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  • richardmitnick 11:33 am on July 19, 2019 Permalink | Reply
    Tags: , Dr. Jennifer Andrews, Earthquake Alert system, , , , The Seismo Lab at Caltech,   

    From Caltech: Women in STEM “What is it Like to be a Caltech Seismologist During a Big Quake?” Dr. Jennifer Andrews 

    Caltech Logo

    From Caltech

    July 18, 2019
    Robert Perkins
    (626) 395‑1862
    rperkins@caltech.edu

    When an earthquake strikes, seismologists at Caltech’s Seismological Laboratory spring into action.

    2

    1
    Dr. Jennifer Andrews

    An arm of Caltech’s Division of Geological and Planetary Sciences (GPS), the Seismo Lab is home to dozens of seismologists who collaborate with the United States Geological Survey (USGS) to operate one of the largest seismic networks in the nation.Together, they analyze data to provide the public with information about where the quake occurred and how big it was. That information not only helps first responders, but feeds into the scientific understanding on earthquakes and when and where the next big quicks are likely to strike.

    After the two largest Ridgecrest earthquakes on July 4 and 5 (Magnitude 6.4 and 7.1, respectively), Caltech staff seismologist Jen Andrews was part of the Seismo Lab team that rushed to respond. Recently, she described that experience.

    Where were you when the earthquakes hit?

    For Thursday’s quake, I was at home in my shower. I didn’t even realize at the time that it was a quake. But when I got out and looked at my computer, I saw the report. Then the phone rang, and it was Egill [Hauksson, research professor of geophysics at Caltech], saying it was time to go to work. It was all hands on deck.

    For Friday’s quake, I was at the ballet at the Dorothy Chandler Pavilion in Downtown Los Angeles. They’d just finished act 1 and were in intermission, so fortunately no dancers were on stage to be knocked off their feet. I was in the balcony, so the movement I felt was probably amplified by the height (and also the soft sediment beneath Downtown). The chandeliers were swaying, but no one panicked. As soon as I felt it shake, I started counting. We felt it as a roll, so I knew the epicenter wasn’t right beneath us. Once I reached 20 seconds, I knew this was a big earthquake, even bigger than the first one. I immediately got in a taxi and headed straight to campus.

    What did you do next?

    Here at the Seismo Lab, it’s our responsibility to verify that all of the info we’re putting out about earthquakes—the locations and magnitudes, for example—are correct. We’re responsible for getting info about the origin out within two minutes of the shaking, so we have fully automated systems that send updates to the National Earthquake Information Center right away. All of that happens without anyone touching anything, before we can even get to our desks. But once we get there, we look at the waveforms and make sure that we’re correctly identifying the P and S waves. [During an earthquake, several types of seismic waves radiate out from the quake’s epicenter, including compressional waves (or P-waves), transverse waves (or S-waves), and surface waves.] We also know the speed at which seismic waves should travel, so we can use that to make sure that we’re correctly identifying where the quake originated. It turns out that the automatic systems did a brilliant job of getting most of the information correct.

    What is it like to be in the Seismo Lab after a big earthquake?

    It’s very busy. There’s a lot of people: seismologists, news reporters, even curious students and people who are on campus who just want to know what’s going on. Meanwhile, we have a lot of issues to deal with: we have seismologists on the phone with state representatives and others speaking to members of the press, while still others are trying to process data coming in from seismometers. Within a few hours of a quake, the USGS tries to figure out who’s going out to the location of the earthquake, and what equipment they’ll be taking. For the Ridgecrest quakes, they did flyovers in a helicopter looking for ruptures, and then sent people on the ground to measure the rupture. They then deployed additional seismometers so that we could get an even clearer picture of any aftershocks.

    How long after the earthquake will things stay busy for you?

    The media attention relaxes after a few hours or days, but I’m going to be looking at the data we gathered from these quakes for a long time. I was here every day over the holiday weekend and the following week working on it. It could take months or even years for our group to process all the data.

    Do you learn more from big earthquakes like these than you do from little ones?

    You learn different things. The data will be incorporated into earthquake hazard models, though likely will not make big changes. But these quakes in particular were interesting, as two perpendicular faults were involved. We can study the rupture dynamics, which you can’t resolve in smaller quakes. Also, having two strong quakes caused variations in fault slip and ground motion that will be important to study and understand.

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 10:48 am on June 6, 2019 Permalink | Reply
    Tags: A unique opportunity to drill and instrument the seismogenic zone of large megathrust earthquakes, , , Earthquake Alert system, , , ,   

    From temblor: “Osa Peninsula, Costa Rica: A unique opportunity to drill and instrument the seismogenic zone of large megathrust earthquakes” 

    1

    From temblor

    June 4, 2019
    Jason Patton

    1
    The past month of earthquakes in Costa Rica with boundaries show that the Osa peninsula is unusually close to the Middle America Trench, and has a very high quake rate.

    A unique opportunity exists on the Osa peninsula, in southern Costa Rica to drill and instrument a locked but mature segment of the Middle America Subduction Zone. This section of the Middle America Subduction Zone has suffered large (Mw=7.2-7.4) earthquakes in 1853, 1904, 1941 and 1983. With an average recurrence interval of roughly 40 years, the timing is now right to drill, instrument and record data of unrivalled importance before, during and after the next megathrust earthquake in this region. Because the subduction of young, rejuvenated and thickened lithosphere, the megathrust surface is unusually shallow. As a consequence, the plate interface beneath the peninsula lies just 4-8 km beneath land. This shallow depth and record of large quakes makes drilling possible and instrumentation fruitful.

    2
    Cross-section with no vertical exaggeration showing the close proximity of the Osa peninsula to the megathrust surface of the Cocos Plate.

    Geodetic observations indicate that the subduction interface is locked beneath the peninsula (Kobayashi et al., 2014) (Figure 3). The surface geology has been mapped to a large extent based on continuous shoreline exposures and observations in bedrock rivers that incise in response to rapid uplift. These uplift rates have been quantified for the Quaternary (the past million years) using marine terraces and their associated sedimentary cover. A series of trench-parallel, landward-dipping reverse faults have been mapped on the peninsula, which could represent splay faults and fluid conduits, similar to those imaged offshore Nankai, Japan, site of a great earthquake sequence in 1944-1946. All of this makes the Osa Peninsula an ideal site to compare with very important results that are currently obtained in the Nankai Trough. Since the trench is only 15-30 km from the SW coastline of Osa Peninsula, submarine cables with seafloor instrumentation, power and data transmission can be deployed and tight to borehole instrumentation, at a much lower cost than in other subduction zones.

    Drilling and instrumenting the hole with seismometers, strainmeters, tiltmeters, fluid samplers and fluid flow meters, among other instruments, would establish the relationship between surface geology, subsurface, upper plate structure, surface deformation and the characteristics of the locked interface. We noted that there are signals only detectable by borehole observatories. The integration of these datasets would be an unprecedented opportunity to relate continuous processes such as strain accumulation and seismic slip with the longer-term evolution of the margin that manifests as upper plate deformation, and permanent uplift. This will be a chance to contribute to the international efforts carried out all over the world, as part of a global network of observatories to understand the genesis of large and destructive earthquakes, to help estimate the seismic hazards and therefore contribute to the reduction of their potential damage.

    Large efforts have been invested in trying to drill to the source of large subduction earthquakes. Since most of these seismogenic zones are located offshore and deeper than current ‘non-riser’ and ‘riser’ drilling technology, very few subduction zone candidates exist where this goal can be achieved. Even at these offshore locations, the cost and time required to drill them are extremely large. Furthermore, strong ocean currents can cause an interruption in drilling operations for a large part of the year and therefore require the drilling vessel to transit to the site many times, which further increases the cost. On the other hand, drilling a 6-8 km hole on land would cost roughly $10-$30 million USD and could be completed in less than 6 months.

    We welcome inquiries from scientists and institutions for such an ambitious yet discounted project. Resources from ICDP, national funding agencies, and potentially other foundations could be leveraged to take advantage of this unique tectonic and temporal opportunity.

    References:

    Bangs, N. L., K. D. McIntosh, E. A. Silver, J. W. Kluesner, and C. R. Ranero (2015), Fluid accumulation along the Costa Rica subduction thrust and development of the seismogenic zone, J. Geophys. Res. Solid Earth, 120, 67–86, doi:10.1002/2014JB011265.

    Kobayashi, D., P. LaFemina, H. Geirsson, E. Chichaco, A. A. Abrego, H. Mora, and E. Camacho (2014), Kinematics of the western Caribbean: Collision of the Cocos Ridge and upper plate deformation, Geochem. Geophys. Geosyst., 15, 1671–1683, doi:10.1002/2014GC005234.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 1:47 pm on May 20, 2019 Permalink | Reply
    Tags: Earthquake Alert system, Large Earthquake in Papua New Guinea re-ruptures major fault in just 19 years: More to follow?, , ,   

    From temblor: “Large Earthquake in Papua New Guinea re-ruptures major fault in just 19 years: More to follow?” 

    1

    From temblor

    May 19, 2019
    Tiegan Hobbs, Ph.D., Postdoctoral Seismic Risk Scientist at Natural Resources Canada (@THobbsGeo)

    A magnitude-7.5 quake broke the same fault that produced a magnitude-8.0 quake in 2000, an extraordinarily short recurrence time that also broke all our rules.

    A major earthquake struck eastern Papua New Guinea (PNG) on Tuesday, May 14th at 22:58 local time. No injuries have been reported, although shaking from this Mw 7.5 earthquake was felt up to 250 km (150 mi) away from the epicenter. The maximum shaking intensity (the so-called ‘Modified Mercalli level VII’) would have been sufficient to cause considerable damage in poorly built houses which are common in the region.

    1
    Map showing the location of the 14 May 2019 Mw 7.5 Papua New Guinea Earthquake, as well as the M=7.1 quake on the other side of the country, which struck just a week beforehand.

    According to Dr. Baptiste Gombert, postdoctoral researcher at Oxford University, the event “occurred on the left-lateral Weitin fault [WF in the map below], a major structure of the New Ireland”. ‘Left-lateral’ means that whatever side you are on, the other side moved to the left. This fault marks the boundary between the North and South Bismarck microplates.

    Beyond the Weitin Fault, this region has “every type of plate boundary” according to Dr. Jason Patton from the California Geological Survey and Adjunct Professor at Humboldt State University. For example, compression and shear between the Pacific and Australian Plates results in subduction along the New Britain Trench, rifting in the Woodlark Basin in addition to the observed strike-slip activity in the area of Tuesday’s quake.

    2
    Modified from Holm et al., [2019], this map shows the regional tectonics. Looking like broken shards of glass, there is a complex interaction of possibly inactive subduction from the north and south, along with rifting, subduction, thrusting, and strike slip faults in between. The USGS moment tensor (beachball) from Tuesday’s Mw 7.5 event (blue star) suggests left-lateral motion on the Weitin Fault between the North and South Bismarck Plates. The event rattled residents of New Ireland (NI), the elongate island through which the Weitin Fault runs.

    First Ever Measurement of Onshore Repeated Rupture

    What makes this event so exciting, though, is that it’s not the first major earthquake in this location. A Mw 8.0 event in the year 2000 resulted in up to 11 m of slip along a 275-km-long (165 mi) fault, with 20 aftershocks with magnitude greater than 5 [Tregoning et al., 2001]. The proximity of this week’s hypocenter to the larger quake 19 years ago had Dr. Sotiris Valkaniotis, geological consultant, wondering if they ruptured the same portion of the fault. With some quick work processing satellite imagery, Dr. Valkaniotis produced what is believed to be the first recording of repeated on-land rupture of a fault.

    ________________________________________

    And we have slip! Co-seismic displacement on Weitin Fault, New Ireland, #PNG after the strong M7.5 May 15 2019 #earthquake. Displacement analysis from optical image correlation using #Sentinel2 images from @CopernicusEU and #MicMac. Repeat rupture on the same fault as 2000! pic.twitter.com/5PFZdfOdPj

    — Sotiris Valkaniotis (@SotisValkan) May 16, 2019
    ________________________________________

    The figure in the above tweet, reproduced below, shows several meters of offset across the fault for both earthquakes. It’s preliminary, but it suggests that this fault is extremely active. For reference, Dr. Gombert describes the Weitin Fault as having a strain rate that is approximately 4 times that of the San Andreas in California. That’s important, because it presents a rare opportunity to study an entire seismic cycle from one large earthquake to the next in under 20 years—which appears to be unprecedented. These observations could help answer important questions about whether earthquakes repeatedly rupture the same patch, and what tends to initiate these events. In many places, such as the Cascadia Subduction Zone with its roughly 500-year recurrence period, this is simply not possible.

    3
    Surface displacements in the North-South direction for the most recent Mw 7.5 event and the 2000 Mw 8.0 event on the Weitin Fault. Measurements made using optical correlation of Sentinel-2 and Landsat-7 satellite data.

    2000 Mw 8.0 Event Triggered Large Nearby Earthquakes

    Within 40 hours of the 16 November 2000 earthquake on the Weitin Fault, which was itself preceded by a 29 October 2000 Mw 6.8 foreshock, two events of magnitude 7.4 and 7.5 were recorded nearby [Park & Mori, 2007]. The events were found to be consistent with static stress triggering from the mainshock, and with a previous observation of Lay and Kanamori [1980] that earthquakes in this part of the world tend to occur in doublets: two large mainshocks that are close in space and time rather than the typical mainshock-aftershock sequence. It begs the question “will there be more?”

    Triggering of Aftershocks From This Sequence?

    Three strong aftershocks have so far struck near the mainshock: two Mw 5.0 events on Tuesday May 14th and Thursday May 16th, and a Mw 6.0 on Friday May 17th. Although we don’t yet know the type of faulting that occurred in these events, we can evaluate how the Mw 7.5 mainshock may have promoted them. A Coulomb Stress calculation shows that the epicentral locations of these events experienced stress loading of 112, 4, and 2 bars, respectively, assuming a similar fault geometry. This is well in excess of a 1 bar triggering threshold, suggesting that all three of these fault locations were brought closer to failure by the mainshock. In the map below, regions of red shading indicate areas prone to aftershocks – extending along an over 100 km swath of New Ireland. Given that the previous event in 2000 was able to trigger relatively large earthquakes on the Weitin [Geist and Parsons, 2005], the coming days and weeks could bring more large events to the region.

    Without doubt, the data from this earthquake sequence will illuminate the stress evolution of this rapidly straining strike-slip fault and serve as a helpful natural laboratory for understanding similar strike-slip systems which are slower to reveal their mysteries.

    5
    Stress change caused by the 14 May 2019 mainshock (green star), for faults with similar orientation. Red indicates areas of positive Coulomb stress change (up to 5 bars), and cyan shows regions with negative stress change (to -5 bars). The two Mw 5.0 and one Mw 6.0 aftershocks (white diamonds) experienced Coulomb stress loading upwards of the triggering threshold.

    Tsunami Warnings for Papua New Guinea and the Solomon Islands

    Strike-slip faults, like the Weitin and the San Andreas in California, generate dominantly horizontal motions, and so are fortunately unlikely to launch large tsunami unless they trigger undersea landslides. Some 9 minutes after the earthquake started, the Pacific Tsunami Warning Center assessed a tsunami threat for regions within 1000 km of the quake: mainly Papua New Guinea and the Solomon Islands. The threat was called off within about an hour and a half, with wave heights reaching less than 0.3 m (about a foot).

    It is important to remember in the coming days and weeks, however, that aftershocks are also capable of producing dangerous tsunami. Following the Mw 8.0 New Ireland earthquake on the same fault in 2000, runups from the mainshock and triggered aftershocks were greater than 3 meters (9 feet) in some locations [Geist and Parsons, 2005]. This was partly due to the thrust mechanism of the aftershocks, which causes greater vertical displacement and therefore larger potential for tsunami. Because many populations in this region live close to the coast, the safest strategy is self-evacuation. This means that if you feel shaking that is strong or long, head to high ground without waiting to be told.

    Read More:

    USGS reports

    https://earthquake.usgs.gov/earthquakes/eventpage/us70003kyy/executive

    https://earthquake.usgs.gov/earthquakes/eventpage/us70003l05/executive

    https://earthquake.usgs.gov/earthquakes/eventpage/usd000a1im/executive

    https://earthquake.usgs.gov/earthquakes/eventpage/us70003mus/executive

    Tsunami warnings

    https://www.tsunami.gov/events/PHEB/2019/05/14/19134000/1/WEPA40/WEPA40.txt

    https://www.tsunami.gov/events/PHEB/2019/05/14/19134000/3/WEPA40/WEPA40.txt

    Social Media:

    https://twitter.com/SotisValkan/status/1129069849131401216 (imagery based surface displacement measurement comparison)

    Geist, E. L., & Parsons, T. (2005). Triggering of tsunamigenic aftershocks from large strike‐slip earthquakes: Analysis of the November 2000 New Ireland earthquake sequence. Geochemistry, Geophysics, Geosystems, 6(10).

    Holm, R. J., Tapster, S., Jelsma, H. A., Rosenbaum, G., & Mark, D. F. (2019). Tectonic evolution and copper-gold metallogenesis of the Papua New Guinea and Solomon Islands region. Ore Geology Reviews, 104, 208-226.

    Lay, T., & Kanamori, H. (1980). Earthquake doublets in the Solomon Islands. Physics of the Earth and Planetary Interiors, 21(4), 283-304.

    Park, S. C., & Mori, J. (2007). Triggering of earthquakes during the 2000 Papua New Guinea earthquake sequence. Journal of Geophysical Research: Solid Earth, 112(B3).

    Tregoning, P., McQueen, H., Lambeck, K., Stanaway, R., Saunders, S., Itikarai, I., Nohou, J., Curley, B., Suat, J. (2001). Progress Report on Geodetic Monitoring of the November 16, 2000 – New Ireland Earthquake. Australian National University, Research School of Earth Sciences, Special Report 2001/3. http://rses.anu.edu.au/geodynamics/tregoning/RSES_SR_2001-3.pdf

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:58 am on February 26, 2019 Permalink | Reply
    Tags: "Seismic warning to India: A shock strikes just north of Delhi", , , Earthquake Alert system, , , , ,   

    From temblor: “Seismic warning to India: A shock strikes just north of Delhi” 

    1

    From temblor

    February 25, 2019
    By Aron Mirwald, M.Sc.
    Ross Stein, Ph.D., Temblor, Inc.

    On 20 February 2019, a magnitude 4 earthquake struck 50 km (30 mi) north from the megacity, Delhi. A magnitude 4 earthquake is not large. If it occurs nearby, it can be felt, and may generate some damage, but it is almost never fatal. This earthquake was no exception: shaking has been reported to be weak to moderate. So, what is interesting about it? Actually, there is a lot to be learned from small, seemingly unimportant events like this. Let us use this earthquake as a means to explore the seismic risk in India.

    1
    This portion of a new map from the GEM Foundation shows the expected cost of earthquake damage relative to the cost of construction, averaged over time, everywhere on Earth. The Himalayan Foothill Thrust region lights up in a band of yellow-orange high risk. The risk is the product of a very high seismic hazard and an extremely high population density. Pakistan and Nepal are also seen to be at very high risk, followed by greater Kabul in Afghanistan.

    Crushing into Eurasia

    We know from GPS observations that the Indian plate is moving 16-18 millimeters per year towards the Eurasian plate (Bilham & Ambraseys, 2005). It is pushed, rather forcefully, below the Eurasian plate. This movement has resulted in the creation of the beautiful Himalayas. But it has also resulted in a thrust-zone, where many great earthquakes occur. In this zone, the two plates are interlocked most of the time. Since the plate is pushing from behind, the stress builds up until it is strong enough to overcome fault friction. Then, very large earthquakes can occur.

    3
    India has been in a slow-motion crash into Asia for 40 million years, as attested to by 500 years of historical reports of great earthquakes, with events striking principally along India’s northern frontier. Some 400 million people live in the Ganges Plain (bright white area), just south of the frontier, in India and Bangladesh. Graphic by Volkan Sevilgen.

    At the thrust-zone between the Indian and Eurasian plate, at least three earthquakes with a magnitude larger than 8 have occurred in medieval times (Bilham, 2009). The recurrence time of this kind of earthquakes is unknown, but it is speculated that earthquakes of similar magnitude are overdue (Bilham & Ambraseys, 2005).

    But, if we take a closer look at last week’s earthquake, it did not occur at the thrust-zone, but further in the south. Actually, there are many earthquakes known to occur far away from the thrust-zone. This could be easily explained, if the Indian plate itself was deformed substantially. But, we know that the rate of deformation along the continent is very low, around 5 millimeters per year (Bilham, 2004). This is too low to explain frequent seismicity.

    The Indian plate is buckling

    The explanation is simple, yet fascinating. The downward bend of the Indian plate beneath the Himalayas has resulted in a ‘flexure’, or bending, of the plate. We can see this in the cross—section south of the thrust-zone. There is first an upward bulge of approximately 450 meters, followed by a smaller depression (Bilham, 2004). Now, we can imagine the plate to be like a wooden stick: it bends before it breaks.

    4
    In this cross-section, North is to the right, and South to the left. The buckling of the Indian plate leads to a bulge south of Delhi, along with shallow tensional quakes, as struck last week. The great earthquakes strike along the thrust fault at right (purple), as well as other sites of concentrated buckling (Bilham, 2009).

    The first part that breaks is usually a weak spot. In tectonic plates such weak spots are often faults, planes where the rock has failed previously due to an earthquake. Weak planes, that were previously stable, will be pushed towards the thrust-zone, and move through the bulge, where the change of flexural stresses can trigger failure and consequently earthquakes.

    Seismic Risk in India

    Now we can put the picture together: Seismic risk in India can be attributed to earthquakes at the thrust-zone below the Himalayas, and to seismicity within the continent due to flexural stresses.

    Delhi, as an example of a vulnerable metropolis, has a history of being affected by both (Iyengar, 2000). There are around 20 seismically active faults in the vicinity of Delhi capable of generating earthquakes. The Mahendraghar–Dehradhun fault, for instance, could produce an earthquake of magnitude 7 (Iyengar & Gosh, 2004). One problem is, that the fast urbanization in Delhi is leading to a rising number of buildings that are helpless even in the face of moderate sized earthquakes (Mittal et. al., 2012).

    India is one of the countries with the most earthquake-related deaths. Just in the past century, over 100.000 people have died due to earthquakes in the country (Bilham, 2009). This number is unlikely to decrease in the future: Its population is growing, and the consequential increase of fatalities is foreseeable (Bilham, 2009).

    5
    India lies in the cluster of countries in the upper right, which have suffered the largest number of large earthquakes and fatalities since the turn of the 19thth century (Bilham, 2009)

    Hope for the best, prepare for the worst

    In their hazard assessment, Nath and Thingbaijam (2012) conclude that the Bureau of Indian Standards underestimates the seismic risk in India and recommend updating the National Building Code. But there is another problem. According to Bilham (2009), constructers often ignore existing building codes. Among the reasons he lists are ignorance of the seismic risk and the engineering solutions to it, people trying to save money, and corruption. He suggests that this could be solved by education. If everybody knew about the fatal consequences of not including earthquake resistant structures, it would occur less frequently.

    Often, action is only taken after the disaster, but that is too late for many. So, this comparatively small earthquake near the megacity should be a reminder to put more effort to raise awareness of the earthquake risk.

    References

    Bilham, Roger. The seismic future of cities. Bulletin of Earthquake Engineering, 2009, 7. Jg., Nr. 4, S. 839.
    Bilham, Roger, et al. Earthquakes in India and the Himalaya: tectonics, geodesy and history. Annals of GEOPHYSICS, 2004.
    Bilham, Roger; AMBRASEYS, Nicholas. Apparent Himalayan slip deficit from the summation of seismic moments for Himalayan earthquakes, 1500–2000. Current science, 2005, S. 1658-1663.
    GEM Global Seismic Risk Map (Silva et al., 2018), https://maps.openquake.org/map/global-seismic-risk-map/
    Iyengar, R. N. Seismic status of Delhi megacity. Current Science, 2000, 78. Jg., Nr. 5, S. 568-574.
    Iyengar, R. N.; GHOSH, Susanta. Microzonation of earthquake hazard in greater Delhi area. Current Science, 2004, 87. Jg., Nr. 9, S. 1193-1202.
    Mittal, Himanshu, et al. Stochastic finite modeling of ground motion for March 5, 2012, Mw 4.6 earthquake and scenario greater magnitude earthquake in the proximity of Delhi. Natural Hazards, 2016, 82. Jg., Nr. 2, S. 1123-1146.
    Nath, S. K.; Thingbaijam, K. K. S. Probabilistic seismic hazard assessment of India. Seismological Research Letters, 2012, 83. Jg., Nr. 1, S. 135-149.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 12:38 pm on February 13, 2019 Permalink | Reply
    Tags: Earthquake Alert system, , Indonesia’s devastating 2018 earthquake was a rare ‘supershear’ according to UCLA-led study, , ,   

    From UCLA Newsroom: “Indonesia’s devastating 2018 earthquake was a rare ‘supershear,’ according to UCLA-led study” 


    From UCLA Newsroom

    February 11, 2019

    Stuart Wolpert
    310-206-0511
    swolpert@stratcomm.ucla.edu

    1
    Pierre Prakash/European Union

    In supershear quakes, the rupture moves faster than the shear waves, which produces more energy in a shorter time, making supershears unusually destructive.

    The devastating 7.5 magnitude earthquake that struck the Indonesian island of Sulawesi last September was a rare “supershear” earthquake, according to a study led by UCLA researchers.

    Only a dozen supershear quakes have been identified in the past two decades, according to Lingsen Meng, UCLA’s Leon and Joanne V.C. Knopoff Professor of Physics and Geophysics and one of the report’s senior authors. The new study was published Feb. 4 in the journal Nature Geoscience.

    Meng and a team of scientists from UCLA, France’s Geoazur Laboratory, the Jet Propulsion Laboratory at Caltech, and the Seismological Laboratory at Caltech analyzed the speed, timing and extent of the Palu earthquake. Using high-resolution observations of the seismic waves caused by the temblor, along with satellite radar and optical images, they found that the earthquake propagated unusually fast, which identified it as a supershear.

    Supershear earthquakes are characterized by the rupture in the earth’s crust moving very fast along a fault, causing the up-and-down or side-to-side waves that shake the ground — called seismic shear waves — to intensify. Shear waves are created in standard earthquakes, too, but in supershear quakes, the rupture moving faster than the shear waves produces more energy in a shorter time, which is what makes supershears even more destructive.

    “That intense shaking was responsible for the widespread landslides and liquefactions [the softening of soil caused by the shaking, which often causes buildings to sink into the mud] that followed the Palu earthquake,” Meng said.

    In fact, he said, the vibrations produced by the shaking of supershear earthquakes is analogous to the sound vibrations of the sonic boom produced by supersonic jets.

    2
    Lingsen Meng. Penny Jennings/UCLA

    UCLA graduate student Han Bao, the report’s first author, gathered publicly available ground-motion recordings from a sensor network in Australia — about 2,500 miles away from where the earthquake was centered — and used a UCLA-developed source imaging technique that tracks the growth of large earthquakes to determine its rupture speed. The technique is similar to how a smartphone user’s location can be determined by triangulating the times that phone signals arrive at cellphone antenna towers.

    “Our technique uses a similar idea,” Meng said. “We measured the delays between different seismic sensors that record the seismic motions at set locations.”

    The researchers could then use that to determine the location of the rupture at different times during the earthquake.

    They determined that the minute-long quake moved away from the epicenter at 4.1 kilometers per second (or about 2.6 miles per second), faster than the surrounding shear-wave speed of 3.6 kilometers per second (2.3 miles per second). By comparison, non-shear earthquakes more at about 60 percent of that speed — around 2.2 kilometers per second (1.3 miles per second), Meng said.

    Previous supershear earthquakes — like the magnitude 7.8 Kunlun earthquake in Tibet in 2001 and the magnitude 7.9 Denali earthquake in Alaska in 2002 — have occurred on faults that were remarkably straight, meaning that there were few obstacles to the quakes’ paths. But the researchers found on satellite images of the Palu quake that the fault line had two large bends. The temblor was so strong that the rupture was able to maintain a steady speed around these bends.

    That could be an important lesson for seismologists and other scientists who assess earthquake hazards.

    “If supershear earthquakes occur on nonplanar faults, as the Palu earthquake did, we have to consider the possibility of stronger shaking along California’s San Andreas fault, which has many bends, kinks and branches,” Meng said.

    Supershear earthquakes typically start at sub-shear speed and then speed up as they continue. But Meng said the Palu earthquake progressed at supershear speed almost from its inception, which would imply that there was high stress in the rocks surrounding the fault — and therefore stronger shaking and more land movement in a compressed amount of time than would in standard earthquakes.

    “Geometrically irregular rock fragments along the fault plane usually act as barriers preventing earthquakes,” Meng said. “However, if the pressure accumulates for a long time — for decades or even hundreds of years — an earthquake will eventually overcome the barriers and will go supershear right away.”

    Among the paper’s other authors are Tian Feng, a UCLA graduate student, and Hui Huang, a UCLA postdoctoral scholar. The UCLA researchers were supported by the National Science Foundation and the Leon and Joanne V.C. Knopoff Foundation.

    The other authors are Cunren Liang of the Seismological Laboratory at Caltech; Eric Fielding and Christopher Milliner of JPL at Caltech and Jean-Paul Ampuero of Geoazur.


    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 11:39 am on October 27, 2018 Permalink | Reply
    Tags: , , Earthquake Alert system, , , , , , The Whistle   

    From temblor: “The Whistle: Are We Ready for the Big One?” 

    1

    From temblor

    October 24, 2018

    Jason R. Patton, Ph.D.
    Ross Stein, Ph.D.
    Volkan Sevilgen, M.Sc.

    It Has Happened Before

    The southern San Andreas fault (SSAF) is a plate boundary strike-slip fault, where the Pacific plate moves northward relative to the North America plate. There have been large earthquakes on this fault in historic time, including the 1857 Forth Tejon earthquake. This 1857 earthquake is estimated to have been a magnitude 7.9 earthquake (larger than the recent earthquake in Sulawesi, Indonesia). There is also a record of prehistoric earthquakes on this fault, spanning the past 5000 years (Weldon et al., 2004; Sharer et al., 2007). These authors have determined that the average time between earthquakes on the SSAF is 105 years. However, the time between earthquakes ranges from 31 – 165 years. This large variation in inter-event time periods makes it more difficult to know when the next “Big One” will happen.

    The USGS prepares earthquake scenarios based on our knowledge about past earthquakes and how future earthquakes may behave based on our empirical knowledge. Below is a USGS scenario map for the part of the SSAF that ruptured in the 1857 Fort Tejon earthquake. The color scale represent relative earthquake shaking intensity based on the Modified Mercalli Intensity scale. Warmer colors represent areas of stronger ground shaking. While the map below is based on a computer model, this is a good estimate of how strongly the ground shook in 1957. Note how the strongest ground shaking is adjacent to the fault.

    1
    USGS Shakemap scenario map for the southern San Andreas fault, showing an estimate of shaking intensity from an earthquake similar in length and magnitude to the 1857 Fort Tejon earthquake. The part of the fault that slips in this scenario earthquake is shown as a black line, very similar to the known extent of the 1857 earthquake.

    Several governments and non-governmental organizations prepare estimates of seismic hazard so that people can ensure their building codes are designed to mitigate these hazards. The Global Earthquake Model (GEM) is an example of our efforts to estimate seismic hazards on a global scale. Temblor.net uses the Global Earth Activity Rate (GEAR) model to provide estimates of seismic hazard at a global to local scale (Bird et al., 2015). GEAR blends quakes during the past 41 years with strain of the Earth’s crust as measured using Global Positioning System (GPS) observations.

    Below is a map prepared using the temblor.net app. Seismicity from the past month, week, and day are shown as colored circles. The temblor app suggests that this region of San Bernardino, CA has an earthquake score of 93. To find out what your earthquake score is, enter your address in the app at temblor.net.

    2
    Earthquake Risk map for southern California, centered on the inland empire. Active faults are shown as red lines. Earthquakes from the past month are shown as circles.

    We Imagine the Consequences

    Earthquakes can cause damage to buildings and other infrastructure due to the shaking intensity. The closer to the earthquake, the higher the intensity. Buildings are located on different types of bedrock and this can amplify the shaking intensity in places. How do we know this? We have made direct observations of the damage from earthquakes.

    There is ample evidence of what happens during earthquakes like what will occur on the SSAF someday. The same fault system, further north, has also ruptured in historic time. In 1868, the Hayward fault (a sister fault of the San Andreas) had an earthquake that caused extensive damage in the San Francisco Bay area. The USGS and the California Geological Survey are using the 150 year anniversary of this earthquake as a tool to educate the public about earthquake hazards along these active faults in northern California. Here is a short video about the HayWired Scenario. More can be learned about how to outsmart disaster at the “HayWired” website here.

    Below is a photo from the aftermath of the 1868 Hayward fault earthquake.

    3
    This photo shows damage to “Pierce’s House,” a building damaged by the 1868 Hayward fault earthquake. Image source: Wikimedia Commons, public domain.

    Another historic earthquake that caused extensive damage in California is the 1906 Great San Francisco earthquake, another San Andreas fault earthquake. The damage from this earthquake included building damage and fire. Fire is one of the most common damaging effects of an earthquake like what will happen someday on the SSAF.

    Below is a photo showing damage to houses that were built on material that did not perform well during an earthquake.

    4
    Photo of houses following the 1906 San Francisco earthquake. Photo from National Archives Record Group 46, public domain.

    The combination of hazard and exposure (people) is what we call risk. When people are exposed to earthquake hazards, they are at risk from damage due to those earthquakes. If there is an earthquake and nobody is there to experience the earthquake, there is no risk. One major difference between 1868, 1906, and today is that there are more people that live close to these earthquake faults. While the average number of earthquakes stays relatively constant through time, as the population grows in earthquake country, the risk also grows.

    Do you live along the San Andreas or some other plate boundary fault? What about another kind of fault?

    To learn more about your exposure to these hazards, visit temblor.net.

    When is the next Big One?

    We don’t know when the next southern San Andreas fault big earthquake will happen. Currently there are no scientifically demonstrated ways to predict earthquakes. We can use the frequency of past earthquakes and patterns of earthquake occurrence (current seismicity) to estimate the chance that an earthquake will occur over a period of time.

    These estimates of future earthquake occurrence are called forecasts. Most people are familiar with weather forecasts, but we know much less about earthquakes than we do about weather. Because of this, earthquake forecasts may not have the same amount of accuracy that weather forecasts do. However, these forecasts are based on the latest cutting edge science about earthquakes and are monumentally better than simply tossing a coin. The cool thing about these forecasts is that the science behind them improves over time as we learn more about how earthquakes happen. This is another improvement over coin tosses, which flip pretty much the same as they did since coins were invented.

    The Whistle is an upcoming series of broadcasts produced by the Empire Network, a collaboration between KVCR, PBS, and National Public Radio.

    This four-part documentary series that dives into earthquake science, history, local and international earthquakes and tsunamis, California preparedness and immediate response, prevention, mitigation, retrofits, resilience, sustainability, conservation, incentives, challenges, new technologies… and solutions. Are we ready for the Big One?

    The first episode airs on October 25 and we will learn about earthquakes and the San Andreas fault:

    ______________________________________________________
    Earthquakes and the San Andreas fault. The Ring of Fire. What do we know about earthquakes today? What causes them, how often, why we know the Big One is due. Evolution of seismology and our understanding of earthquakes and plate tectonics. How did the First Nations and early European settlers deal with Earthquakes before modern technology? How dangerous is the threat and how much of an impact can a big earthquake cause? What will happen when the next big one hits?
    ______________________________________________________

    Episode 2 covers how our immediate response might unfold during and following the Big One. Episode 3 reviews our knowledge of the current state of infrastructures (buildings, roads) and how an earthquake might impact these investments in society. Finally, the 4th episode presents an evaluation of how we have improved our ability to be resilient in the face of disasters from the Big One following decades of applying the scientific method to our observations of earthquakes. How will Earthquake Early Warning work and how will we benefit from this? Learn more by watching The Whistle.

    The premiere for “The Whistle, Are We Ready for the Big One?” premieres on Thursday Oct. 25. Watch the first episode on television, or head to this website where the video will be available to stream online.

    3

    References

    Bird, P., Jackson, D. D., Kagan, Y. Y., Kreemer, C., and Stein, R. S., 2015. GEAR1: A global earthquake activity rate model constructed from geodetic strain rates and smoothed seismicity, Bull. Seismol. Soc. Am., v. 105, no. 5, p. 2538–2554, DOI: 10.1785/0120150058

    Sharer, K.M., Weldon, R.J.III., Fumal, T.E., and Biasi, G., 2007. Paleoearthquakes on the Southern San Andreas Fault, Wrightwood, California, 3000 to 1500 B.C.: A New Method for Evaluating Paleoseismic Evidence and Earthquake Horizons in Bull. Seismol. Soc. Am., v. 97, no. 4, p. 1054–1093, DOI: 10.1785/0120060137

    Weldon, R., Sharer, K.M., Fumal, T., and Biasi, G., 2004. Wrightwood and the Earthquake Cycle: What a Long Recurrence Record Tells Us About How Faults Work in GSA Today, v. 14, no. 9, doi: 10.1130/1052-5173(2004)0142.0.CO;2

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 11:33 am on October 18, 2018 Permalink | Reply
    Tags: Earthquake Alert system, , , ,   

    From UCLA Newsroom: “The evolution of earthquake science” 


    From UCLA Newsroom

    October 11, 2018

    1
    Jonathan Stewart, a professor in the UCLA Department of Civil and Environmental Engineering, at a Los Angeles Department of Water and Power facility.

    It’s a scene of post-mayhem disaster. In front of the Acacia residential building on the west end of the UCLA campus. Victims are everywhere, bleeding, confused, in and out of consciousness. A small boy in a baseball hat and shorts is laid out on a red tarp. “Very low pulse,” says one of the people who helped carry him over, before rushing back to the search and rescue. It’s hard to tell if anyone hears her, given the commotion. Nearby, a woman sits upright, a drop of blood rolling out of her ear and down her cheek, and another woman props her bloodied leg inside a makeshift cardboard splint.

    A few dozen first responders move victims onto colorcoded tarps — green for the most stable, yellow for those in need of a medic and red for the most critical. One of the vested first responders kneels beside the boy to check his pulse, and quickly stands up again. “We have a dead over here,” she calls out. But there’s no time to stop.

    This is the aftermath of a 6.8 magnitude earthquake centered on the Santa Monica Fault just south of campus. It’s the “big one” that Southern Californians had known could one day happen. That day is today.

    Except it’s not. The “victims” are all actors, the injuries painted on and the small boy alive and well. The first responders are volunteers from the Community Emergency Response Team, running a drill to test emergency response procedures on campus.

    While this 6.8 quake didn’t actually happen, through the work of researchers and scientists across UCLA, we know with certainty the probable impact of such a temblor, how to warn those who would feel its shaking, how to plan around its destructive power and even how to ensure that buildings like the Acacia dorms don’t fall. From the deepest motions of our planet’s structure to the foundations of our buildings to the crucial urban systems underpinning modern society, UCLA research is increasing our understanding of how the land beneath us moves and how to survive a major quake.

    It’s estimated that up to 3,000 people died in San Francisco in 1906 as a result of the 7.9 magnitude quake, and more than 140,000 died in the 1923 Great Kanto earthquake in Japan. Fortunately, in more recent years, particularly in the United States, earthquake-caused deaths have been relatively rare. Unlike in the past, when buildings crumbled and crushed the people inside, we now know how to construct buildings that can withstand quakes.

    We learned from buildings that fell. In 1994, a 6.7 magnitude earthquake that struck in the San Fernando Valley destroyed or significantly damaged an estimated 90,000 buildings. Of the approximately 60 people killed, 33 were in buildings that fell. The most common were small apartment buildings perched over space left largely empty for parking. With enough shaking, the apartments come crashing down on the mostly hollow space below.

    Scott Brandenberg, a professor of civil and environmental engineering at the UCLA Henry Samueli School of Engineering and Applied Science, studies the impact of earthquakes on the built environment. He lives in a soft story building.“It’s hard to find buildings in the area I can afford,” he says. Soft story buildings were not designed to resist earthquake forces specified in the current building code and should be evaluated for retrofit. A number of these buildings collapsed during the 1994 Northridge earthquake.

    Today, Brandenberg’s building, as well as thousands of others across the region, have been retrofitted through mandatory retrofit ordinances.

    Learning from the past is key to UCLA’s earthquake research across multiple fields. Brandenberg, for example, is creating an international database on liquefaction, the phenomenon sometimes observed during earthquakes in which soil flows like a liquid, causing land to slide and foundations of buildings to slip away. He and his colleagues are collecting case studies globally that shed light on the consequences of liquefaction. “We’ve never really had a database that was available to the whole community,” says Brandenberg. He hopes broad access to the data will help standardize the science behind liquefaction.

    Researchers can’t wait around for earthquakes to strike; the stakes are too high. Jonathan Stewart, a professor in the Department of Civil and Environmental Engineering, has been collecting global data on earthquake impacts on levees and their associated drinking water systems. His major area: a 1,100-mile network of levees in California that directs water into the State Water Project’s drinking and agricultural water conveyances and prevents salt water intrusion from the San Francisco Bay.

    “A good 40 percent of the water in Southern California is coming through this system,” he says. “So the stability and viability of this system is really a big deal. For the system to work, the whole thing has to work. You can’t just analyze individual sections. So we’ve developed methods to do that.”

    Based on previous seismic activity near levee systems in places like Japan, Stewart and his colleagues can determine the dynamic properties of the peat that makes up much of the structure of the foundation beneath the levees in the Delta, learning how much levees can settle, which can lead to overtopping and cause erosion. They also determine how much soil to keep in reserve to patch breaches that occur. Add in computer modeling, and they can predict worst-case scenarios for disruptions to the system and plan how to respond.

    This type of systemic, model-based thinking is new for earthquake research, a field that has been largely based on observations of specific events. “[Research] was being done on a small-time basis: individual faculty and their grad students working on something, producing a paper, other people doing the same thing, and we get all these disparate documents out there,” Stewart explains. “And then somebody has to figure out what to do with it all. We’re trying to change the paradigm by which this research is done.”

    Practitioners outside the university who are applying this information to the real world say UCLA’s work is making a difference. Ronald T. Eguchi is president and CEO of Long Beach-based ImageCat, which creates earthquake maps and hazard exposure models for buildings and infrastructure. The company serves clients like NASA and FEMA, as well as private insurance companies. Eguchi says the data coming out of UCLA has helped make these maps more accurate.

    “Without [that UCLA] research, I don’t think we’d be able to come up with these quantitative assessments,” he says. “We use that information to [learn] what the extent of displacement or ground failure would be.”

    Useful data can come from surprising sources. Engineering Professor Ertugrul Taciroglu, who studies earthquake effects on urban infrastructure — ports, bridges, power lines — has developed a way to use the abundant images available from Google to visually analyze infrastructures and develop predictive simulation models to quantify their seismic risks.

    “My students and I developed computer codes that will locate each bridge and examine it through Google Street from multiple angles. Our algorithms extract key measurements, such as column heights and cross-sectional dimension. We use those measurements to create a structural analysis model. We intend to do that for all 25,000 bridges in California,” he says. These images are remarkably accurate. Taciroglu says he has checked his models using Google’s images against Caltrans’ original bridge blueprints, and the measurements match up at the sub-inch level.

    Google Earth also has been a rich source of data for power lines and other lifeline transmission corridors that provide electricity across the state. “I can create structural analysis models of power distribution networks by going around with my preprogrammed robot inside Google Earth and extracting where the transmission towers are, the length of the cables, the sag of the cables,” Taciroglu adds. “Because I know where they are, I know what kind of an earthquake shaking we can expect in the future for each structure.”

    Knowing how transmission lines may fail in a big earthquake can show, for example, what hospitals should be better equipped with backup power. Modeling which bridges could fail will help us understand how to prevent parts of cities from being cut off from essential services. Taciroglu says a dream project would be to integrate all this information into one massive model that encompasses the full complexity of an entire urban region and all its interrelated risks. Such a tool would be immensely valuable to government agencies, facility operators and insurance agencies.

    This kind of metropolitan-wide thinking may not be far off. A task force of UCLA earthquake researchers is developing plans to better integrate systems thinking and earthquake consciousness into the operations of city and county entities, such as utilities. “Lifeline infrastructure can be impacted by big earthquakes,” says Ken Hudnut, a geophysicist for Risk Reduction at the U.S. Geological Survey and a lecturer in UCLA’s Department of Civil and Environmental Engineering, who advises the L.A. Mayor’s Office of Resilience.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 7:32 am on September 21, 2018 Permalink | Reply
    Tags: A tectonic squeeze may be loading three thrust faults beneath central Los Angeles, Earthquake Alert system, , , ,   

    From temblor: “A tectonic squeeze may be loading three thrust faults beneath central Los Angeles” 

    1

    From temblor

    September 17, 2018
    Chris Rollins

    Thrust-faulting earthquakes are a fact of life in Los Angeles and a threat to it. Three such earthquakes in the second half of the 20th century painfully etched this ongoing threat to life, limb and infrastructure into the memories and the backs of the minds of many who call this growing metropolis home. The first struck 40 seconds after 6:00 AM on a February morning in 1971 when a section of a thrust fault beneath the western San Gabriel Mountains ruptured in a magnitude 6.7 tremor. The earthquake killed 60 people, including 49 in the catastrophic collapse of the Veterans Administration Hospital in Sylmar, the closest town to the event (which is often referred to as the Sylmar earthquake). Among other structures hit hard were the newly built Newhall Pass interchange at the junction of Interstate 5 and California State Route 14, of which multiple sections collapsed, and the Van Norman Dam, which narrowly avoided failure in what could have been a cruel deja vu for a city that had been through deadly dam disasters in 1928 and 1963.

    1
    Devastation at the Veterans Administration Hospital in the 1971 Sylmar earthquake. Photo courtesy of Los Angeles Times.

    Sixteen years later, a section of the Puente Hills thrust fault ruptured in the magnitude 5.9 Whittier Narrows earthquake, killing eight people in East Los Angeles and bringing attention to a class of thrust faults that do not break the surface, called “blind” thrust faults, which will go on to form a key part of this story. Then early on another winter morning in 1994, an even more deeply buried blind thrust fault ruptured beneath the San Fernando Valley in the magnitude 6.7 Northridge earthquake, causing tens of billions of dollars in damage and taking 57 lives. One of the fatalities was Los Angeles police officer Clarence Wayne Dean, who died on his motorcycle when a span of the Newhall Pass interchange that had been rebuilt following the 1971 Sylmar earthquake collapsed again as he was riding across it in the predawn darkness.

    2
    Collapse of the Newhall Pass (I-5/CA-14) interchange in the 1994 Northridge earthquake. Officer Dean died on the downed section of overpass at right. The interchange has since been renamed the Clarence Wayne Dean Memorial Interchange in his memory. Photo courtesy of CNN.

    LA’s problem: The squeeze

    Thrust earthquakes like these, in which the top side of the fault is thrust up and over the bottom side, will likely strike Los Angeles again in the 21st century. They may in fact pose a greater hazard to the city than earthquakes on the nearby San Andreas Fault because they can occur directly beneath the central metropolitan area. This means that a city that has found so much of its identity and place in history from being improvised as it went, and from being a cultural and economic melting pot, now faces the unwieldy task of readying its diverse infrastructure and populace for the strong shaking these kinds of earthquakes can produce.

    One way that the earthquake science community has been assessing the seismic hazard in LA is by using geodesy – long-term, high-precision monitoring of the deformation of the Earth’s surface – to locate sections of faults that are stuck, or locked, causing the Earth’s crust to deform around them. It is this bending of the crust, or accumulated strain, that is violently released in earthquakes; therefore the locations where this bending is taking place might indicate where future earthquakes will occur, and perhaps how large and frequent they could be. Several decades of geodetic monitoring have shown that the greater Los Angeles area is being squeezed from north to south at roughly 8-9 millimeters per year (⅓ inch per year), about one-fourth the rate at which human fingernails grow. Thrust faults, such as those on which the Sylmar, Whittier Narrows and Northridge earthquakes struck, are ultimately driven by this compression.

    3
    Geodetic data, tectonics and material properties relevant to the problem. Dark blue arrows show the north-south tectonic compression inferred by Argus et al. [2005] after removing deformation caused by aquifer and oil use. Black lines are faults, dashed where blind. Background shading is a measure of material stiffness at the surface based on the Community Velocity Model [Shaw et al., 2015]. “Beach balls” show the locations and senses of slip of the 1971 Sylmar, 1987 Whittier Narrows and 1994 Northridge earthquakes. Figure simplified from Rollins et al. [2018].

    Why the science is still very much ongoing

    The task of linking the north-south tectonic squeeze to specific faults encounters several unique challenges in Los Angeles. First, the city sits atop not only active faults but also several aquifers and oil fields that have long provided part of its livelihood and continue to be used today, which deforms the crust around them. Geodetic data are affected by this anthropogenic deformation, to the extent that a recent study used these data to observe Los Angeles “breathing” water from year to year and even to resolve key hydrological properties of particular sections of aquifers. This spectacular deformation, which furnishes science that can be used in resource management around the world, has the unfortunate effect of obscuring the more gradual north-south tectonic shortening in Los Angeles in these data.

    4
    Animation from Riel et al. [2018] showing long-term subsidence of the Earth’s surface due to use of the Los Angeles and Santa Ana aquifers.

    Second, the faults are a complex jumble. The crust underlying Los Angeles is cut by thrust faults, strike-slip faults like the San Andreas Fault and subparallel to it, and other strike-slip faults nearly perpendicular to it. Although these faults all take part in accommodating the gradual north-south squeeze, the relative contributions of the thrust and strike-slip faults in doing so has been the subject of debate. The problem of estimating strain accumulation on subsurface faults is also generally at the mercy of uncertainties as to how faults behave at depth in the Earth’s crust and how they intersect and link up.

    Third, Los Angeles sits atop a deep sedimentary basin, created when a previous episode of extension created a “hole” in the crust that was gradually filled by sediments eroded off the surrounding mountain ranges. These sedimentary layers are more easily deformed than the stiffer rocks in the mountains around the basin, complicating the problem of estimating strain accumulation at depth from the way the surface is deforming. Finally, as in the case of the Puente Hills Fault, some of the major thrust faults in Los Angeles do not break the surface but are “blind.” This means that the bending of the crust around locked sections of these faults is buried and more difficult to detect at the surface.

    5
    Basin sediments affect the relationship between fault slip and deformation at the surface by up to 50% for the cases of the Puente Hills Fault (left) and Compton Fault (right). For the same fault slip, the basin is more compliant and so the Earth’s surface is displaced more (red arrows) than if it were absent (blue arrows). Figure simplified from Rollins et al. [2018].

    Three thrust faults may be doing a lot of the work

    Several important advances over the past two decades have paved pathways towards overcoming these challenges. The signal of deformation due to water and oil management can be subtracted from the geodetic data to yield a clearer picture of the tectonic shortening. The geometries of faults at depth have also come into focus, as earth scientists at the Southern California Earthquake Center and Harvard University have compiled decades of oil well logs and seismic reflection data to build the Community Fault Model, a detailed 3D picture of these complex geometries. A parallel effort has yielded the Community Velocity Model, a 3D model of the structure and composition of the Southern California crust that is internally consistent with the fault geometries.

    6
    A cross section of faults and earthquakes across central Los Angeles from Rollins et al. [2018]. Red lines are faults, dashed where uncertain; pairs of arrows along the thrust faults show their long-term sense of slip. White circles are earthquakes. Basin structure is from the Community Velocity Model.

    Recently, a team of researchers from Caltech, JPL and USC (with contributions from many other earthquake scientists) has begun to put these pieces together. Their approaches and findings were published in the Journal of Geophysical Research (JGR) this summer. On the challenge presented by the complex array of faults, the study found that the strike-slip faults probably accommodate less than 20% of the total shortening at the max, leaving the rest to be explained by thrust faulting or other processes. Three thrust faults, the Sierra Madre, Puente Hills and Compton faults, stand out in particular as good candidates. All three appear to span the Los Angeles basin from west to east, and the Puente Hills and Sierra Madre faults have generated moderate earthquakes in the last three decades, including the Whittier Narrows shock and a magnitude 5.8 tremor in 1991. Paleoseismology (the study of prehistoric earthquakes) has also revealed that these three faults have each generated multiple earthquakes in the past 15,000 years whose magnitudes may have exceeded 7.0.

    7
    Alternative models of how quickly strain is accumulating on the Compton, Puente Hills and Sierra Madre Faults, assuming that the transition between completely locked (stuck) and freely slipping patches of fault is gradual (left) or sharp (right), simplified from Rollins et al. [2018]. Gray lines are major highways.

    How fast is stress building up on these faults?

    Exploring a wide range of assumptions (such as whether the transitions between stuck and unstuck sections of faults may be gradual or abrupt), the team inferred that the Sierra Madre, Puente Hills and Compton faults appear to be partially or fully locked and building up stress on their upper (shallowest) sections. The estimated total rate of strain accumulation on the three faults is equivalent to a magnitude 6.7-6.8 earthquake like the Sylmar earthquake once every 100 years, or a magnitude 7.0 shock every 250 years. These back-of-the-envelope calculations, however, belie the fact that this strain is likely released by earthquakes across a wide range of magnitudes. The team is currently working to assess just how wide this range of magnitudes practically needs to be: whether the strain can be released as fast as it is accruing without needing to invoke earthquakes larger than Sylmar and Northridge, for example, or whether the M>7 thrust earthquakes inferred from paleoseismology are indeed a likely part of the picture over the long term.

    This picture of strain accumulation will sharpen as the methods used to build it are improved, as community models of faults and structure continue to be refined, and especially as more high-resolution data, such as that used to observe LA “breathing” water, is brought to bear on the estimation problem. The tolls of the Sylmar, Whittier Narrows and Northridge earthquakes in lives and livelihoods are a reminder that we should work as fast as possible to understand the menace that lies beneath the City of Angels.

    References

    Argus, D. F., Heflin, M. B., Peltzer, G., Crampé, F., & Webb, F. H. (2005). Interseismic strain accumulation and anthropogenic motion in metropolitan Los Angeles. Journal of Geophysical Research: Solid Earth 110(B4).

    Riel, B. V., Simons, M., Ponti, D., Agram, P., & Jolivet, R. (2018). Quantifying ground deformation in the Los Angeles and Santa Ana coastal basins due to groundwater withdrawal. Water Resources Research 54(5), 3557-3582.

    Rollins, C., Avouac, J.-P., Landry, W., Argus, D. F., & Barbot, S. D. (2018). Interseismic strain accumulation on faults beneath Los Angeles, California. Journal of Geophysical Research: Solid Earth 123, doi: 10.1029/2017JB015387.

    Shaw, J. H., Plesch, A., Tape, C., Suess, M. P., Jordan, T. H., Ely, G., Hauksson, E., Tromp, J., Tanimoto, T., & Graves, R. (2015). Unified structural representation of the southern California crust and upper mantle. Earth and Planetary Science Letters 415: 1-15.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:54 am on September 14, 2018 Permalink | Reply
    Tags: , , Earthquake Alert system, Earthquake research, EPOS-European Plate Observing System, , ,   

    From Horizon The EU Research and Innovation Magazine : “Plate tectonics observatory to create seismic shift in earthquake research” 

    1

    From Horizon The EU Research and Innovation Magazine

    13 September 2018
    Gareth Willmer

    1
    A 6.2-magnitude earthquake in Amatrice, Italy, in August 2016 killed nearly 300 people. Image credit – Amatrice Corso by Mario1952 is licensed under Creative Commons CC-BY-SA-2.5 and 2016 Amatrice earthquake by Leggi il Firenzepost is licensed under CC BY 3.0

    We may never be able to entirely predict earthquakes such as those that hit central Italy in 2016, but we could better assess how they’re going to play out by joining up data from different scientific fields in a new Europe-wide observatory, say scientists.

    In 2016 and early 2017, a series of major earthquakes rocked central Italy. In the hill town of Amatrice, one magnitude-6.2 earthquake devastated the town and claimed the lives of nearly 300 people, with hundreds more injured.

    Richard Walters, an assistant professor in the Department of Earth Sciences at Durham University, UK, has been studying a variety of datasets to understand how these quakes played out.

    Durham U bloc

    From Durham University

    He and his colleagues found that a network of underground faults meant there was a series of seismic events rather than one major earthquake – a finding that could help scientists predict how future seismic events unroll.

    ‘We were only able to achieve this by analysing a huge variety of datasets,’ said Dr Walters. These included catalogues of thousands of tiny aftershocks, maps of earthquake ruptures measured by geologists clambering over Italian hillslopes, GPS-based ground-motion measurements, data collected by a satellite hundreds of kilometres up, and seismological data from a global network of instruments.

    ‘Many of these datasets or processed products were generously shared by other scientists for free, and were fundamental to our results,’ he said. ‘This is how we make big advances.’

    At the moment, this type of research can rely on having a strong network of contacts and disadvantage those without them. That’s where a new initiative called the European Plate Observing System (EPOS), set to launch in 2020, comes in.

    The aim is to create an online tool that brings together data products and knowledge into a central hub across the solid Earth science disciplines.

    ‘The idea is that a scientist can go to the EPOS portal, where they can find a repository with all the earthquake rupture models, historical earthquake data and strain maps, and use this data to make an interpretative model,’ said Professor Massimo Cocco, the project’s coordinator.

    ‘A scientist studying an earthquake, a volcano, a tsunami, and so on, needs to be able to access very different data generated by different communities.’

    __________________________________________________

    ‘While in Europe’s current climate politicians may be putting up borders, scientists in those same countries are trying even harder to break down national barriers.’

    Dr Richard Walters, Durham University, UK
    __________________________________________________

    Mosaic

    At the moment, findings on solid Earth science at a European scale are scattered among a mosaic of hundreds of research organisations. The challenge is to incorporate a variety of accessible information from many different scientific fields, using a combination of real-time, historical and interpretative data.

    EPOS will integrate data from 10 areas of Earth science, including seismology, geodesy, geological data, volcano observations, satellite data products and anthropogenic – or human-influenced – hazards.

    It will help build on the type of data integration that happened after the Amatrice quake, in which the lead organisation behind EPOS – Italy’s National Institute of Geophysics and Volcanology (INGV) – was involved in coordinating and fostering data sharing.

    This included real-time data from temporary sensor deployments, as well as seismic hazard maps, satellite data products and geophysical data – leading to a first model of the quake’s causative source within 48 hours to aid emergency planning.

    So far, a prototype of the portal has been developed and it will now be tested by users over the coming year to make sure it meets needs.

    Dr Walters said that EPOS is right on time. ‘Projects like EPOS are especially timely and valuable right now, as many of the subdisciplines that make up solid Earth geoscience are entering the era of big data,’ he said.

    Eyjafjallajökull

    The eruption of Icelandic volcano Eyjafjallajökull in 2010 highlights another issue that EPOS is hoping to improve – the challenge of coordination across borders. Though this event did not cost human lives, it had a much wider impact in Europe, leading to flights being grounded throughout the region and costing airlines an estimated €1.3 billion.

    In such cases, said Prof. Cocco, it helps to know factors such as the ash’s composition, something that affects how a plume travels but is not necessarily included in the models of meteorologists. That knowledge could be gained through access to volcanology data, and also used by aviation authorities and airlines, potentially to design systems to protect engines.

    Prof. Cocco said the idea is that EPOS could also be used by people outside the research community to ‘increase the resilience of society to geohazards’. An engineer or organisation could use data on ground shaking or earthquake occurrence to aid safe exploitation of resources or evaluate risks in building a nuclear power plant, for example.

    In addition, the aim is to make it easier for students or young scientists to interpret data through tools, software, tutorials and discovery services, rather than having access to just raw data. ‘Otherwise, you are providing only usability to skilled scientists,’ said Prof. Cocco. ‘This, to me, is the only way to achieve open science.’

    At present, the EPOS community comprises about 50 partners across 25 European countries, with hundreds of research infrastructures, institutes and organisations providing data. The organisation has, meanwhile, submitted a final application to become a legal entity known as a European Research Infrastructure Consortium (ERIC), with a decision establishing the ERIC expected within the next two months. This official status will aid integration with other national and European organisations, and have benefits in the allocation of funding, said Prof. Cocco.

    Professor Giulio Di Toro, a structural geologist at the University of Padova in Italy, said it is great to have this type of hub to bring information together and improve access, but also important to ensure that it doesn’t lead to an increase in bureaucracy. If institutions come up against funding issues, it could also pose a challenge to their ability to share data, he added: ‘If for some years you don’t get grants, you will not produce data to share.’

    Meanwhile, Dr Walters sees a positive spirit reflected in these types of initiative. ‘While in Europe’s current climate politicians may be putting up borders,’ he said, ‘scientists in those same countries are trying even harder to break down national barriers, and working together to build something better for everyone.’

    The implementation phase of EPOS is being part-funded by the EU. If you liked this article, please consider sharing it on social media.

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

     
  • richardmitnick 2:43 pm on September 7, 2018 Permalink | Reply
    Tags: , , Earthquake Alert system, , , , , The ongoing earthquake sequence on the island of Hokkaido Japan   

    From temblor: “The ongoing earthquake sequence on the island of Hokkaido, Japan” 

    1

    From temblor

    September 6, 2018
    Jason Patton
    Jason R. Patton, Ph.D., Ross Stein, Ph.D., Shinji Toda, Ph.D, Volkan Sevilgen, M.Sc.

    The Nation of Japan is one of the most seismically active regions in the world and the people of Japan devote significant efforts to be resilient in the face of these hazards associated with earthquakes. These hazards include ground shaking, tsunami, landslides, and liquefaction. The historical knowledge of these hazards extends centuries into the past. Because of their efforts to learn using scientific methods, the world has learned more about earthquake processes.

    Everyone can benefit from learning about their exposure to natural hazards from earthquakes. To learn more about your exposure to these hazards, visit temblor.net.

    In this report, we discuss the ongoing earthquake sequence on the island of Hokkaido, Japan. Below is a map that shows the epicenter for the mainshock, an earthquake with a magnitude M = 6.6. This map shows the coastline and active faults. There are over 700 aftershocks plotted here.

    1
    Figure 1: Regional seismicity map showing earthquake epicenters from the past 30 days. Faults are in red.

    The major source of earthquakes in Japan are the numerous plate boundary fault systems, which include subduction zones, “forearc sliver” strike slip faults, and a collision zone (another form of convergent plate boundary). The figure below is from the American Geophysical Union blog “Trembling Earth,” written by Dr. Austin Elliot. Great earthquakes, quakes with M ≥ 8.0, in the 20th century include the 1923 Great Kantō subduction earthquake and the 1944 and 1946 Tōnankai and Nankai subduction earthquakes. Subduction zones are convergent plate boundaries where an oceanic plate is subducting beneath a continental or oceanic plate. These events helped shape the earth science programs in Japan, especially regarding efforts to learn about subduction zone processes. The 2011 M 9.1 Tohoku-oki subduction zone earthquake generated a trans-pacific tsunami and reminded the public that their efforts to be resilient are well founded.

    2
    Figure 2: Oblique view showing the configuration of the plate boundaries in the region of Japan.

    The various plates and how they are configured is very complicated in Japan and we learn more about them every year. The recent M 6.6 Sapporo earthquake along the southern part of Hokkaido, Japan was also associated with a plate boundary, but not a subduction zone. In northern Japan, the North America/Okhotsk plate is moving southwestward and converging towards the Amuria/Eurasia plate. This plate motion leads to northeast-southwest oriented compression. This compression has led to the formation of tectonic deformation and thrust faults involved in the Hidaka Collision Zone. Collision zones are convergent plate boundaries where two continental plates are converging. An analogical collision zone is the collision of the India and Eurasia plates that form the Himalayas. The map below shows a generalized view of the geologic rocks in Japan, along with the location of different plate boundary faults (Van Horne et al., 2013). The Hidaka Collision Zone is labeled on the map. I placed a blue star in the location of the M 6.6 earthquake.

    3
    Figure 3: Geologic map of Japan showing the plate boundaries and key tectonic features including the Hidaka Collision Zone (Van Horne et al., 2016).

    Ground Shaking

    The M 6.6 Sapporo earthquake generated significant ground shaking and triggered landslides across the region. There are 3 main factors that control the intensity of ground shaking from earthquakes: (1) the magnitude of the earthquake, (2) the distance from the earthquake, and (3) the earth materials between the earthquake and one’s location. Earthquake magnitude is a measure of the amount of energy released during an earthquake, while intensity is a measure of how strongly the ground shakes (and how damaging the shaking is). It makes sense that when there is a larger magnitude, there is the potential for stronger shaking and a higher intensity. The magnitude does not change with distance, but intensity does. The further away from the earthquake source, the less shaking one might observe.

    Here is a figure prepared using the J-SHIS Japan Seismic Hazard Information website. The color represents Peak Ground Acceleration, a measure of ground shaking. The units are also in g, an acceleration, where g = 9.8/m2. If ground shaking is about 1 g, there is possibly enough energy to throw materials into the air (like rocks, cars, or buildings). The symbols represent locations where instruments made these acceleration measurements. Between symbols, the color represents an estimate of the ground shaking at those locations. Note that one site near the earthquake epicenter has a measured acceleration of 1.5 g!

    4
    Figure 4: Ground shaking map showing Peak Ground Acceleration (PGA) represented by color.

    Many governments and non-governmental organizations prepare estimates of seismic hazard so that people can ensure their building codes are designed to mitigate these hazards. The Global Earthquake Model (GEM) is an example of our efforts to estimate seismic hazards, though on a global scale. Temblor.net uses the Global Earth Activity Rate (GEAR) model to prepare estimates of seismic hazard at a global to local scale (Bird et al., 2015). Each of these models incorporate earthquake information from different sources including, but not limited to, fault slip rates, records of prehistoric earthquakes, historic seismicity, and strain of the Earth’s crust as measured using Global Positioning System (GPS) observations.

    Below is a map prepared using the temblor.net app. The rainbow color scale represents the change of a given earthquake magnitude, for a given location, within the lifetime of a person. The temblor app suggests that this region could have an earthquake of M 7.1 in a human lifetime.

    5
    Figure 5: Global Earthquake Activity Rate map for this region of the northwest Pacific. Warmer colors represent regions that are more likely to experience a larger earthquake than the regions with cooler colors. Seismicity from the past is shown and the location of the M 6.6 earthquake is located near the blue teardrop symbol.

    Landslides

    There are many different ways in which a landslide can be triggered. The first order relations behind slope failure (landslides) is that the “resisting” forces that are preventing slope failure (e.g. the strength of the land) are overcome by the “driving” forces that are pushing this land downwards (e.g. gravity). The ratio of resisting forces to driving forces is called the Factor of Safety (FOS). We can write this ratio like this:

    FOS = Resisting Force / Driving Force

    When FOS > 1, the slope is stable and when FOS < 1, the slope fails and we get a landslide. The illustration below shows these relations. Note how the slope angle α can take part in this ratio (the steeper the slope, the greater impact of the mass of the slope can contribute to driving forces).

    6
    Figure 6: Landslide force balance diagram showing how driving and resisting forces balance for a stable slope.

    Some factors that change this ratio include rainfall, over steepening of the slope, undercutting of the base of the slope, and earthquakes. There are other factors as well.

    Japan recently experienced the most severe Typhoon in decades, which resulted in significant rainfall. When rain water infiltrates into the earth, that water can fill the spaces between soil particles and rock cracks so that the water pressure pushes apart these particles or rocks. If this pressure is large enough, the strength of the material (a resisting force) becomes weaker and there can be a landslide. Even if there is not enough reduction in resisting force, the strength of the material is still potentially weaker.

    Landslide ground shaking can change the Factor of Safety in several ways that might increase the driving force or decrease the resisting force. Keefer (1984) studied a global data set of earthquake triggered landslides. The plot presented here shows that that larger earthquake magnitudes (horizontal axis) can result in landslides across a larger area.

    7
    Figure 7: Spatial extent of landslide triggering by earthquakes relative to earthquake magnitude (Keefer, 1984).

    As a result of the M 6.6 Sapporo earthquake, there were a large number of slope failures in the epicentral region. These landslides have covered many buildings and unfortunately have trapped many dozens of people within the debris. We will learn more about this in the coming days as search and rescue teams respond to this disaster.

    There have been many videos posted online, possibly the best ones from Nippon Hōsō Kyōkai (NHK), Japan’s national public broadcasting organization. NHK also acquired the best aerial videos from the inundation of the 2011 Tohoko-oki earthquake and tsunami. There have also been some excellent comparisons between pre-landslide and post-landslide aerial imagery.

    Here is another spectacular view of some of these triggered landslides here.

    Below is a pair of images that presents a comparison of the landscape from before and after the earthquake. These come from social media here.

    8
    9
    Figure 8: A comparison of imagery from before and from after the earthquake. The earthquake triggered landslides in the second image are identified in this photo by the areas of exposed brown colored soil.

    These landslides appear to be failures within the soil mantle of the hillsides. While these landslides were triggered by the earthquake, it is highly likely that the water content from the Typhoon decreased the Factor of Safety prior to the earthquake. It is possible that without this preceding Typhoon, the slope failures might have been less catastrophic.

    Active Faults in Hokkaido

    There are a number of active crustal faults in southern Hokkaido, Japan. One may view the location of these faults on the Japan Seismic Hazard Information Station (J-SHIS) website here. In addition, estimates for seismic hazard are also placed on that website. For example, the National Seismic Hazard Map for Japan is included there. There are various versions of this map, but the most useful version is the map that shows the chance that an area in Japan will experience earthquake ground shaking at least JMA 6, for the next 30 years. The Japan Meteorological Agency Seismic Intensity Scale (JMA) is an intensity scale with a range of 0 – 7, with 7 being the highest intensity, the strongest ground shaking. To give us an idea about how strong the shaking might be for an earthquake with a JMA 6 intensity, this is what a person might experience: “Impossible to keep standing and to move without crawling.”

    Below is a map that is based upon the J-SHIS website. We plot USGS earthquake epicenters from this earthquake sequence as circles colored relative to their depth with circle size relative to earthquake magnitude. Included in this map are also the active fault sources, shown as red rectangles and black lines. The two active faults in the region are different parts of the Ishikari-teichi-toen fault (the main part and the southern part). Based upon expert knowledge, these faults have the potential to produce an M 7.2 and M 7.1 earthquake for the main part and southern part, respectively. Combined, these faults may produce an M 7.9 earthquake. The USGS fault plane solution (moment tensor) is shown, along with a legend that helps one interpret this diagram. More can be found about these “beach balls” here.

    10
    Figure 9: Earthquake shaking potential and active fault map. Warmer colors (red) represent areas that are more likely to shake strongly (minimum JMA 6) compared to the less warm colors (yellow). Active faults are shown as red rectangles or black lines.

    This M 6.6 earthquake was about 33 km (20 miles) deep, deeper than the active crustal faults in the National Seismic Hazard Map. The earthquake was a thrust or reverse earthquake (oriented as a result of northeast-southwest compression, consistent with the orientation of the Hidaka Collision Zone).

    This M 6.6 earthquake has changed the stresses within the crust surrounding the earthquake. The amount of this stress change is moderate, especially when compared with the amount of stress that is typically released during an earthquake. We label the faults in the above map that may or may not have an increased amount of stress (the Ishikari fault system).

    This change in stress is called a change in “static coulomb stress” and a paper that discusses the fundamental factors controlling these stress increases is from Lin and Stein (2004). There is software available to the public from the USGS to perform these calculations. This software is called “Coulomb 3” and is available online here. An introduction to this software and the physics behind the calculations can be found in Stein (2003).

    An earthquake occurs when the stress is greater than the strength of the rock. Rocks can have strengths that range dozens of Mega Pascal (1,000,000 Pa = 1 MPa). When earthquakes slip they release stress on the order of several to a dozen MPa. In order for an earthquake to trigger another earthquake due to these changes in stress, the triggered earthquake fault needs to have a pre-existing level of stress that is somewhat close to failure.

    Dr. Shinji Toda has calculated the change in static coulomb stress as a result of the M 6.6 earthquake. They prepared two different analyses. (1) Dr. Toda first used a computer model to estimate the increased stress that could be observed on a generic fault parallel to the M 6.6 earthquake. (2) Then Dr. Toda used a computer model to estimate what the increase in stress that might be observed on a known active fault near the M 6.6 earthquake epicenter.

    For both analyses, the process begins by choosing a fault geometry for the source earthquake fault (e.g. the M 6.6 earthquake fault). This includes the size (length and width) and the geometry (angle dip beneath horizontal and compass orientation) of the fault. The analysis also requires information about how much the fault slipped along this fault, which controls the magnitude of these stress changes. Finally assumptions need to be made about the material properties of the crust (i.e. the rheology), which controls the spatial distribution and extent of these stress changes. Dr. Toda used the mainshock focal mechanism and seismic moment, centered in the hypocenter.

    One may then calculate the change in stress on generic receiver faults in the region surrounding the source fault. Receiver faults are the faults that may have triggered earthquakes from an increase in stress. Dr. Toda calculated the change in stress for two potential source fault orientations. The figure below shows that there are regions of increased stress (red) and decreased stress (blue). The units for these stress changes are bar, a measure of force. 1 bar = 100,000 Pascal (Pa), or 0.1 MPa. If there were a fault in the red region, and this fault were parallel to the source fault, those faults have the potential to be triggered by this change in stress. Faults that are parallel to the source fault and are located in blue areas, they would have a decrease in stress, inhibiting the possibility of a triggered earthquake.

    11
    Figure 10: Static coulomb stress change imparted by the M 6.6 earthquake onto generic receiver faults that are parallel to the source fault. Red represents regions of increased stress and blue represents regions of decreased stress.

    The next step is to input the fault geometry for a “receiver” fault based upon known active faults in the National Seismic Hazard Map database. Dr. Toda selected a fault similar to the southern part of the Ishikari fault in the active fault database from Japan. The map below shows the configuration of this experiment (north is up, units on both axes is kilometers), including the shoreline and fault geometry. The source fault is the blue rectangle in the center of the map. The receiver fault is the series of small rectangles that compose a larger rectangle. Notice how the receiver fault overlaps the source fault.

    12
    Figure 11: Static coulomb stress change imparted by the M 6.6 earthquake onto an active fault with a known geometry. Red represents regions of increased stress and blue represents regions of decreased stress.

    The figure here shows that there is a strong decrease in stress (-0.5 bar) in the area of the fault near the epicenter and a modest increase in stress (0.15 bar) further to the north. Drs. Toda and Stein hypothesize that the net effect probably inhibits failure on this receiver fault. The Ishikari fault is capable of producing an earthquake M > 7 and this fault did not rupture during the M 6.6 earthquake. So, those who live in the region would benefit from continuing their efforts to mitigate the earthquake hazards that they are faced with.

    Here is another perspective of these data. The view is from the southeast looking into the Earth.

    13
    Figure 12: Low Angle Oblique Stress Changes: Static coulomb stress change imparted by the M 6.6 earthquake onto an active fault with a known geometry. Red represents regions of increased stress and blue represents regions of decreased stress.
    References:

    Bird, P., Jackson, D. D., Kagan, Y. Y., Kreemer, C., and Stein, R. S., 2015. GEAR1: A global earthquake activity rate model constructed from geodetic strain rates and smoothed seismicity, Bull. Seismol. Soc. Am., v. 105, no. 5, p. 2538–2554, DOI: 10.1785/0120150058

    Keefer, D.K., 1984. Landslides caused by earthquakes. GSA Bulletin 95, 406-421

    Lin, J., and R. S. Stein (2004), Stress triggering in thrust and subduction earthquakes and stress interaction between the southern San Andreas and nearby thrust and strike-slip faults, J. Geophys. Res., 109, B02303, doi:10.1029/2003JB002607

    Stein, R.S., 2003. Earthquake conversations, Scientific American, v. 288, no. 1, p. 72-79

    Travasarou, T., Bray, J.D., Abrahamson, N.A., 2003. Empirical attenuation relationship for Arias Intensity. Earthquake Engineering and Structural Dynamics 32, 1133-1155

    Van Horne, A., Sato, H., Ishiyama, T., 2017. Evolution of the Sea of Japan back-arc and some unsolved issues in Tectonophysics, v. 710-711, p. 6-20, http://dx.doi.org/10.1016/j.tecto.2016.08.020

    More information about the tectonics in this region can be found here.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

    Earthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
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