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  • richardmitnick 8:55 am on August 23, 2019 Permalink | Reply
    Tags: , , Earthquakes, ,   

    From University of Washington: “USGS awards $10.4M to ShakeAlert earthquake early warning system in the Pacific Northwest “ 

    U Washington

    From University of Washington

    August 19, 2019

    The U.S. Geological Survey today announced $10.4 million in funding to the Pacific Northwest Seismic Network, based at University of Washington, to support the ShakeAlert earthquake early warning system. Some $7.3 million of the funding will go to the UW.

    The PNSN is responsible for monitoring earthquakes and volcanoes in Washington and Oregon. It is a partnership between the University of Washington, the University of Oregon and the USGS. The support for the PNSN is among the new ShakeAlert cooperative agreements announced today by the USGS.

    The first year’s funding of $5.4 million to the PNSN begins this month. The UW will receive about $3.75 million in direct support of its PNSN activities and $1.66 million will support the PNSN team at the University of Oregon. The second-year funding, of an additional $5 million, is contingent on approval by Congress and will be similarly shared.

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    Karl Hagel and Pat McChesney, field engineers with the Pacific Northwest Seismic Network team at the University of Washington, install earthquake monitoring equipment on the slopes of Mount St. Helens, with Mount Hood in the distance.Marc Biundo/University of Washington.

    “This investment in the PNSN represents a major increase in federal support for earthquake monitoring in the Cascadia region,” said Harold Tobin, director of the PNSN and professor in the UW’s Department of Earth and Space Sciences. “At the end of the two years of funding we anticipate having essentially doubled the number of seismic stations across our whole region that contribute to real-time earthquake early warning. This would allow for full public alerts of any potentially damaging earthquakes, across our entire region of Washington and Oregon, by the end of the two-year period.”

    This new award will allow for installation of 104 new seismic stations in Washington state and 44 in Oregon, during the two-year period. It will also support improved, more-sophisticated detection of earthquakes as they begin, and new efforts to engage potential users of the warnings.

    ShakeAlert’s network of instruments detect the first, less damaging waves from a major earthquake close to where the earthquake begins. The system then issues alerts for the estimated size and location of the earthquake, providing seconds or minutes of warning before the more damaging ground shaking begins – enough for someone to pull off the road, stop a surgery, or find a safe place to take shelter.

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    A sample warning, with a countdown of the number of seconds until the strong shaking reaches the user.Pacific Northwest Seismic Network

    In the Pacific Northwest’s pilot phase of the system, early adopters in the region have developed pilot projects with guidance and support from the PNSN and USGS, and have received ShakeAlert warning messages for the past two years. These warnings are currently used to trigger loss-reduction measures at critical facilities — such as turning off water valves in public utility districts — before dangerous shaking would arrive.

    The additional funding will support the development of new pilot projects in schools, businesses, communities and critical infrastructure facilities in preparation for the eventual goal of open alerts to the general public, as launched recently in the Los Angeles region. The improvements to PNSN’s network supported by this funding will meet the USGS’ recommended station-density standard for public alerting in almost all areas of Washington and Oregon.

    “It will enable us to rapidly build out our network to produce faster and more accurate alerts for Cascadia Region earthquakes,” Tobin said.

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    Existing Pacific Northwest Seismic Network ShakeAlert stations, as of spring 2019. The new funding will roughly double the number of stations in Washington and Oregon.

    The funding will also support ongoing research to integrate GPS data into ShakeAlert, which will allow quicker estimates of the magnitude of offshore Cascadia Subduction Zone earthquakes as they unfold. The UW is sharing its research in this area with the National Oceanic and Atmospheric Administration and NASA in the hope of improving tsunami-warning capabilities. The UW is working with Central Washington University, also supported by USGS, to receive near-real-time GPS data from across Washington and Oregon that will be integrated into future releases of ShakeAlert.

    The regional ShakeAlert effort began in 2011, when the UW joined the University of California, Berkeley and California Institute of Technology as a primary ShakeAlert center in the developing a West Coast warning system. The Gordon and Betty Moore Foundation awarded $2 million to each university to kick-start ShakeAlert from a research project to an operational system. With support from Congress, the USGS ramped up support for ShakeAlert as the foundation’s seed funding expired.

    Additional support for PNSN operations comes from the U.S. Department of Energy and the states Oregon and Washington. The Washington legislature, in its current biennium budget, allocated $1.24 million over two years for additional enhancements to the ShakeAlert network.

    See the full article here .


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  • richardmitnick 10:25 am on August 10, 2019 Permalink | Reply
    Tags: "A big earthquake in the US Pacific Northwest?", Cascadia megathrust fault, , Earthquakes, , ,   

    From University or Oregon via EarthSky: “A big earthquake in the US Pacific Northwest?” 

    From University or Oregon

    via

    1

    EarthSky

    August 5, 2019
    Miles Bodmer, University of Oregon
    Doug Toomey, University of Oregon

    Most people don’t associate the US Pacific Northwest with earthquakes, but maybe they should. It’s home to the 600-mile (1,000-km) Cascadia megathrust fault, stretching from northern California to Canada’s Vancouver Island.

    1
    Data derived from NaturalEarthData.com, 10m datasets. Projected into NAD83 UTM 9N. Alicia.iverson

    3
    This is the USGS’ scenario ShakeMap for a M9 shock on the Casdadia Subduction Zone. This is not a real event.
    23 December 2016
    Source Earthquakes Shakemap usCasc9.0_se
    Author United States Geological Survey

    The Pacific Northwest is known for many things – its beer, its music, its mythical large-footed creatures. Most people don’t associate it with earthquakes, but they should. It’s home to the Cascadia megathrust fault that runs 600 miles (966 km) from Northern California up to Vancouver Island in Canada, spanning several major metropolitan areas including Seattle and Portland, Oregon.

    This geologic fault has been relatively quiet in recent memory. There haven’t been many widely felt quakes along the Cascadia megathrust, certainly nothing that would rival a catastrophic event like the 1989 Loma Prieta earthquake along the active San Andreas in California. That doesn’t mean it will stay quiet, though. Scientists know it has the potential for large earthquakes – as big as magnitude 9.

    Geophysicists have known for over a decade that not all portions of the Cascadia megathrust fault behave the same. The northern and southern sections are much more seismically active than the central section – with frequent small earthquakes and ground deformations that residents don’t often notice. But why do these variations exist and what gives rise to them?

    Our research tries to answer these questions by constructing images of what’s happening deep within the Earth [Geophysical Research Letters Research], more than 90 miles (144 km) below the fault. We’ve identified regions that are rising up beneath these active sections which we think are leading to the observable differences along the Cascadia fault.

    Cascadia and the ‘Really Big One’

    The Cascadia subduction zone is a region where two tectonic plates are colliding. The Juan de Fuca, a small oceanic plate, is being driven under the North American plate, atop which the continental U.S. sits.

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    The Juan de Fuca plate meets the North American plate beneath the Cascadia fault. Image via USGS.

    Subduction systems – where one tectonic plate slides over another – are capable of producing the world’s largest known earthquakes. A prime example is the 2011 Tohoku earthquake that rocked Japan.

    Cascadia is seismically very quiet compared to other subduction zones – but it’s not completely inactive. Research indicates the fault ruptured in a magnitude 9.0 event in 1700. That’s roughly 30 times more powerful than the largest predicted San Andreas earthquake. Researchers suggest that we are within the roughly 300- to 500-year window during which another large Cascadia event may occur.

    Many smaller undamaging and unfelt events take place in northern and southern Cascadia every year. However, in central Cascadia, underlying most of Oregon, there is very little seismicity. Why would the same fault behave differently in different regions?

    Over the last decade, scientists have made several additional observations that highlight variations along the fault.

    One has to do with plate locking, which tells us where stress is accumulating along the fault. If the tectonic plates are locked – that is, really stuck together and unable to move past each other – stress builds. Eventually that stress can be released rapidly as an earthquake, with the magnitude depending on how large the patch of fault that ruptures is.

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    A GPS geosensor in Washington. Image via Bdelisle.

    Geologists have recently been able to deploy hundreds of GPS monitors across Cascadia to record the subtle ground deformations that result from the plates’ inability to slide past each other. Just like historic seismicity, plate locking is more common in the northern and southern parts of Cascadia.

    Geologists are also now able to observe difficult-to-detect seismic rumblings known as tremor. These events occur over the time span of several minutes up to weeks, taking much longer than a typical earthquake. They don’t cause large ground motions even though they can release significant amounts of energy. Researchers have only discovered these signals in the last 15 years, but permanent seismic stations have helped build a robust catalog of events. Tremor, too, seems to be more concentrated along the northern and southern parts of the fault.

    What would cause this situation, with the area beneath Oregon relatively less active by all these measures? To explain we had to look deep, over 100 kilometers (60 miles) below the surface, into the Earth’s mantle.

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    Green dots and blue triangles show locations of seismic monitoring stations. Image via Bodmer et al., 2018, Geophysical Research Letters.

    Imaging the Earth using distant quakes

    Physicians use electromagnetic waves to “see” internal structures like bones without needing to open up a human patient to view them directly. Geologists image the Earth in much the same way. Instead of X-rays, we use seismic energy radiating out from distant magnitude 6.0-plus earthquakes to help us “see” features we physically just can’t get to. This energy travels like sound waves through the structures of the Earth. When rock is hotter or partially molten by even a tiny amount, seismic waves slow down. By measuring the arrival times of seismic waves, we create 3-D images showing how fast or slow the seismic waves travel through specific parts of the Earth.

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    Ocean bottom seismometers waiting to be deployed during the Cascadia Initiative. Image via Emilie Hooft.

    To see these signals, we need records from seismic monitoring stations. More sensors provide better resolution and a clearer image – but gathering more data can be problematic when half the area you’re interested in is underwater. To address this challenge, we were part of a team of scientists that deployed hundreds of seismometers on the ocean floor off the western U.S. over the span of four years, starting in 2011. This experiment, the Cascadia Initiative, was the first ever to cover an entire tectonic plate with instruments at a spacing of roughly 30 miles (50 km).

    What we found are two anomalous regions beneath the fault where seismic waves travel slower than expected. These anomalies are large, about 90 miles (150 km) in diameter, and show up beneath the northern and southern sections of the fault. Remember, that’s where researchers have already observed increased activity: the seismicity. Interestingly, the anomalies are not present beneath the central part of the fault, under Oregon, where we see a decrease in activity.

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    Regions where seismic waves moved more slowly, on average, are redder, while the areas where they moved more quickly are bluer. The slower anomalous areas 90 miles (150 km) beneath the Earth’s surface corresponded to where the colliding plates are more locked and where tremor is more common. Image via Bodmer et al., 2018, Geophysical Research Letters.

    So what exactly are these anomalies?

    The tectonic plates float on the Earth’s rocky mantle layer. Where the mantle is slowly rising over millions of years, the rock decompresses. Since it’s at such high temperatures, nearly 1500 degrees Celsius (2700 F) at 100 km (60 mi) depth, it can melt ever so slightly.

    These physical changes cause the anomalous regions to be more buoyant – melted hot rock is less dense than solid cooler rock. It’s this buoyancy that we believe is affecting how the fault above behaves. The hot, partially molten region pushes upwards on what’s above, similar to how a helium balloon might rise up against a sheet draped over it. We believe this increases the forces between the two plates, causing them to be more strongly coupled and thus more fully locked.

    A general prediction for where, but not when

    Our results provide new insights into how this subduction zone, and possibly others, behaves over geologic time frames of millions of years. Unfortunately our results can’t predict when the next large Cascadia megathrust earthquake will occur. This will require more research and dense active monitoring of the subduction zone, both onshore and offshore, using seismic and GPS-like stations to capture short-term phenomena.

    Our work does suggest that a large event is more likely to start in either the northern or southern sections of the fault, where the plates are more fully locked, and gives a possible reason for why that may be the case.

    It remains important for the public and policymakers to stay informed about the potential risk involved in cohabiting with a subduction zone fault and to support programs such as Earthquake Early Warning that seek to expand our monitoring capabilities and mitigate loss in the event of a large rupture.

    See the full article here .

    Earthquake Alert

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    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

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  • richardmitnick 11:24 am on July 31, 2019 Permalink | Reply
    Tags: "A Tectonic Plate Under Oregon Is Being Slowly Ripped Apart", , Earthquakes, , Juan de Fuca tectonic plate, , ,   

    From UC Berkeley via Science Alert: “A Tectonic Plate Under Oregon Is Being Slowly Ripped Apart” 

    From UC Berkeley

    via

    ScienceAlert

    Science Alert

    31 JUL 2019
    DAVID NIELD

    Spare a thought for the Juan de Fuca tectonic plate, not long for this world (in tectonic plate terms) as it slowly slides under the continent of North America.

    3
    Map of the Juan de Fuca Plate. No image credit. Wikipedia.

    Geologists are hoping it can help solve one of the biggest mysteries in their field – how tectonic plates die.

    The Juan de Fuca plate is the last remnant of the much bigger Farallon plate, which has been disappearing under North America for tens of millions of years. It’s the perfect opportunity to study how plates eventually get swallowed up, and how that might cause seismic and volcanic activity on the surface.

    In particular, researchers William Hawley and Richard Allen, from the University of California, Berkeley, are interested in a gap that’s appearing in the Juan de Fuca plate – which may in fact represent a tearing of the plate way down below the surface.

    “The tearing not only causes volcanism on North America but also causes deformation of the not‐yet‐subducted sections of the oceanic plate offshore,” write the researchers in their newly published paper [Geophysical Letters Research].

    “This tearing may eventually cause the plate to fragment, and what is left of the small pieces of the plate will attach to other plates nearby.”

    All the rock that gets buried as a plate is subsumed has to go somewhere, and the large-scale deformations and breaks that can occur aren’t easy for scientists to predict or map.

    Using data from 217 earthquakes and more than 30,000 seismic waves, Hawley and Allen have been able to put together a detailed 3D picture of this particular part of the Cascadia Subduction Zone.

    2
    Cascadia subduction zone. USGS.

    Specifically, they identified which parts of the rock were from the Juan de Fuca plate.

    They found what looks like a tear more than 150 kilometres (93 miles) deep, and it matches a previously identified area of weakness on the Juan de Fuca plate at the surface, known as a propagator wake.

    The researchers suggest that as the Juan de Fuca plate turns and twists, parts of it are being pulled off and separated, creating the gap that experts have observed. Some of it might even live on as part of another plate.

    More evidence is needed to be sure of what is happening here, but the hypothesis matches seismic activity around southern Oregon and northern California, as well as unusual patterns of volcanism in the region.

    Those unusual patterns are the volcanoes known as the High Lava Plains in southern Oregon, where the newest eruptions are at the wrong end of the series from where geologists would expect them to be, based on the direction of drift of the North American tectonic plate.

    Fresh volcanic activity caused by the propagator wake and deeper weakness in the Juan de Fuca could perhaps explain this anomaly, the researchers suggest.

    As Juan de Fuca disappears, further research – as well as readings from the EarthScope project and the Cascadia Initiative, which were used in this study – should shed more light on how tectonic plates die, and how they’ve formed the world we live on.

    “In many ways, when we’re looking at these things, we’re looking back in time,” seismologist Lara Wagner from the Carnegie Institution for Science, who wasn’t involved in the study, told National Geographic.

    “If we don’t understand how those processes work[ed] in the past, where we can see the whole story and study it, then our chances of seeing what’s happening today and understanding how that might evolve in the future are zero.”

    See the full article here .

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  • richardmitnick 11:33 am on July 19, 2019 Permalink | Reply
    Tags: , Dr. Jennifer Andrews, , Earthquakes, , , 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 10:43 am on July 7, 2019 Permalink | Reply
    Tags: "Oregon Is About to Get a Lot More Hazardous", , Earthquakes, Landslides and debris flows, , ,   

    From Scientific American: “Oregon Is About to Get a Lot More Hazardous” 

    Scientific American

    From Scientific American

    June 29, 2019
    Dana Hunter

    State leadership is failing its citizens—and there will be a body count.

    1
    Credit: Dale Simonson (CC BY-SA 2.0)

    When you live in an area at as much geologic risk as Oregon, you would expect that government officials would maybe, possibly, take those risks seriously. But the people who currently govern Oregon seem quite determined to ignore hazards and let the state languish unprepared.

    It’s bad enough that legislators voted this month to allow “new schools, hospitals, jails, and police and fire stations” to be built in areas that will most certainly be inundated in the event of a tsunami. Both parties think it’s a good idea now; I doubt they’ll still be feeling great about locating schools right in the path of rampaging seawater when the big one hits. But short-term economic gain outweighs long-term planning, so here we are. What else can we expect from a statehouse where lawmakers who would rather flee the state than be forced to deal with climate change?

    People say they’re willing to accept the risks. However, the state government is now planning to make it far harder for residents to even know what those risks are, because Oregon’s Department of Geology and Mineral Industries (DOGAMI for short) is severely underfunded and will now lose three critically-needed experts on staff as a punishment for going over budget. As if that weren’t bad enough, the governor’s office is considering whether the agency should even continue to exist:

    “In a note on the preliminary budget proposal for the agency, the Joint Ways and Means Committee said the Governor’s office would be “evaluating if the Department should continue to exist as an independent or recommendations to abolish and move the individual programs to other entities.”

    That drastic of a move could come with big consequences,” Avy said.

    “It would be incredibly disruptive to staff and it is likely that some on-going studies would be discontinued,” he said.”Oregon would lose a valued agency and may lose talented staff in our Geological Survey and Services Program which provides a focus on geologic and mineral mapping and natural hazard identification.”

    Can we be real for a minute, here? Oregon is a geologically young state in an active subduction zone, located on an ocean that has subduction zones on both sides, which generate ocean-spanning tsunamis on a regular basis. The local subduction zone, plus Basin and Range crustal stretching and faulting, also produces active volcanoes. Many, many volcanoes. Also, too, all of this folding and faulting and uplifting and volcanoing leaves the state terribly landslide prone. This is not a place where you can safely starve your local geological survey of funds, and then shut it down when it needs extra money to identify and quantify the hazards you face.

    So if you live in Oregon, or even if you just visit, I’d strongly consider writing a polite but serious missive to Governor Kate Brown, letting her know that it would perhaps be a good idea to look further into the possible repercussions of signing that deplorable tsunami bill (I mean, at least take the schools out of the mix!), and also fully fund DOGAMI rather than further crippling it and then stripping it for parts.

    Let’s have a brief tour of Oregon’s geohazards which DOGAMI helps protect us from, then, shall we?

    Tsunamis

    The Oregon coast is extremely susceptible to tsunamis, both generated from Cascadia and from other subduction zones along the Pacific Ocean. You can see evidence of them everywhere.

    1
    Cascadia subduction zone. This is the site of recurring en:megathrust earthquakes at average intervals of about 500 years, including the en:Cascadia Earthquake of en:1700.

    One of the starkest reminders in recent times was the dock that was ripped from the shoreline in Misawa, Japan, in the brutal 2011 Tōhoku Earthquake. The tsunami that sheared it loose and set it afloat also washed ashore in California and Oregon, causing millions of dollars in damage; loss of life in the United States was only avoided due to ample warnings.

    3
    Ocean energy distribution forecast map for the 2011 Sendai earthquake from the U.S. NOAA. Note the location of Australia for scale.

    Just over a year later, the dock washed up on Agate Beach, Oregon.

    At Agate Beach, homes and businesses are built right in the path of the next Cascadia tsunami. I can’t describe to you the eerie sensation you feel turning away from that dock to see vulnerable structures that will be piles of flooded rubble after the next tsunami hits.

    3
    Residences and businesses on Agate Beach. Even a modest tsunami will cause untold damage to these structures. Credit: Dana Hunter

    The people here will have minutes to find high ground after the shaking stops, if that long. There is some high ground nearby, but not much, and perhaps not near enough. Roads will probably be destroyed or blocked in the quake. This is the sort of location the legislature has decided it would be fine to site schools.

    Earthquakes

    6
    The stump of a drowned spruce at Sunset Bay, Shore Acres, OR. Lockwood DeWitt for scale. Credit: Dana Hunter

    Sunset Bay is the site of one of Oregon’s many ghost forests. Here, a Cascadia earthquake dropped the shoreline about 1,200 years ago, suddenly drowning huge, healthy trees in salt water. At least seven spectacular earthquakes have hit the Oregon coast in the past 3,500 years. It may not sound like much, or often… but look to Japan for the reason why we should take the threat extremely seriously. And Oregon doesn’t just have to worry about Cascadia quakes: the state is full of faults, stretching from north to south and from coast to interior.

    Volcanoes

    Huge swathes of Oregon are volcanic. As in, recently volcanic. As in, will definitely erupt again quite soon.

    Mount Hood, a sibling to Mount St. Helens, is right outside of Portland and last erupted in the mid-1800s. It is hazardous as heck.

    6
    Mount Hood reflected in Trillium Lake, Oregon, United States

    But Hood is very, very far from the only young volcano in the state, and evidence of recent eruptions is everywhere. Belknap shield volcano and its associated volcanoes on McKenzie Pass ceased erupting only 1,500 years ago, and the forces that created it are still active today.

    7
    Belknap Crater, Oregon. Cascades Volcano Observatory

    Another volcanic center like it could emerge in the near future. And you see here just a tiny swath of the destruction such a volcanic center causes.

    You know what you really don’t want to be caught unawares by? A volcano. And even once they’ve stopped erupting, the buggers can be dangerous. Sector collapses, lahars, and other woes plague old volcanoes. You need people who can keep a sharp eye on them. And I’m sorry, but the USGS can’t be everywhere at once. Local volcano monitoring is important!

    Landslides and debris flows

    If you’re an Oregon resident, you’ll probably remember how bloody long it took to finish the Eddyville Bypass due to the massive landslide that got reactivated during construction. Steep terrain plus plenty of rain equals lots of rock and soil going where we’d prefer it didn’t.

    Debris flows and landslides regularly take out Oregon roads, including this stretch on a drainage by Mount Hood.

    7
    Construction equipment copes with damage caused by massive debris flows coming down from Mount Hood. Credit: Dana Hunter

    We know from the Oso mudslide just how deadly these mass movements can be. Having experts out there who understand how to map the geology of an area and identify problem areas is critically important, especially in places where a lot of people want to live, work, and play.

    Contact the governor’s office and let her know if you don’t think it’s worth letting a budget shortfall torpedo the agency that should be doing the most to identify these hazards and help us mitigate them.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 10:38 am on July 6, 2019 Permalink | Reply
    Tags: "Magnitude 7.1 earthquake rips northwest from the M6.4 just 34 hours later", Earthquakes, , The M 6.4 quake on July 4 can now be regarded as a foreshock of the M 7.1 quake.   

    From temblor: “Magnitude 7.1 earthquake rips northwest from the M6.4 just 34 hours later” 

    1

    From temblor

    July 6, 2019
    Tiegan Hobbs

    The M 6.4 earthquake loaded the site where the M 7.1 shock nucleated. Now, the M 7.1 has extended the original rupture to the northwest, as well as to the southeast, where it kisses the major Garlock Fault.

    Citation: Ross S. Stein, Tiegan Hobbs, Chris Rollins, Geoffrey Ely, Volkan Sevilgen, and Shinji Toda, (2019), Magnitude 7.1 earthquake rips northwest from the M6.4 just 34 hours later, Temblor, http://doi.org/10.32858/temblor.037

    Rupture of a Previously Unknown Fault

    The town of Ridgecrest was not done shaking after a magnitude 6.4 earthquake on the morning of July 4. An M=7.1 shock ruptured for at least 35 km (20 mi) from the 4 July 2019 epicenter, towards the northwest, and perhaps also for 25 km to the southeast. It is astonishing that there is no continuous mapped fault at the ground surface, despite the near absence of vegetation that can otherwise hide faults. Numerous other faults have been mapped in this region, trending predominantly in a north-south direction, somewhat different than this earthquake. The aftershock alignment, however, is very straight in a northwest-southeast trend, suggesting that beneath the surface must lie a continuous fault. We strongly suspect that the rupture is right-lateral (whichever side you are on, the other moves to the right). The trend is parallel to the San Andreas Fault, but has a strike (or compass orientation) more westerly than most of the nearby surrounding faults.

    1
    Map of the past 40 hours of earthquakes from the USGS (ANSS) catalog, with the inferred sense of fault slip represented by the gray half-arrow pairs. This gives the impression of a northwestward rupture of perhaps 30 km length, which is very short for such a large shock. Because the USGS website is experiencing problems, this might be an incomplete portrayal.

    Did the Rupture Unzip to the Northwest Only, or Also to the Southeast?

    Without knowing about this fault, there was no reason to suspect that such a large earthquake could occur to the north of the July 4 rupture. Fortunately, this is a remote location, with even fewer people living to the northwest of the mainshock than the south.

    While much of the seismicity in the last 48 hours has fallen along two nearly linear faults, aftershocks of this magnitude 7.1 earthquake have formed a cluster to the northwest of the main rupture fault. This cluster, near Little Lake, CA, is approximately 15 km (9 miles) south of the Coso Geothermal Area. That geothermal region is home to abundant seismicity [Hauksson & Unruh, 2007] which is often clustered in swarms at its periphery. All events in this swarm, as of midnight local time on July 5th, are shallower than 10 km depth, consistent with previous swarms in this area.

    2
    This Temblor app map with another 2 hours of events gives a different impression of the M 7.1 aftershocks than the initial USGS map, suggesting that the rupture does not simply extend to the northwest. Based on these aftershocks it appears ‘bilateral’, meaning that the fault unzipped both to the northwest and southwest, for a total length of up to 55 km. This would be more consistent with its magnitude, as a strike-slip M 7.1 typically has a length of about 50 km. If this is correct, then parts of the Garlock Fault might also be brought closer to failure.

    Chain Reaction

    In retrospect, the M 6.4 quake on July 4 can now be regarded as a foreshock of the M 7.1. While generally uncommon, there are many recent examples of occurrences similar to this. The 14 April 2016 M 6.0 Kumamoto shock was followed 28 hours later by a M 7.0 quake on 15 April 2016 that ruptured two major faults that were brought closer to failure by the first event. The 3 November 2002 M 7.9 Denali earthquake on the Denali Fault was preceded by a M 6.7 shock on the Fault on 23 October 2002, 11 days beforehand.

    The epicenter of the M 7.1 was Loaded by the M 6.4 Earthquake

    Preliminary Coulomb stress transfer calculations reveal that the epicenter of the M 7.1 shock was brought 2 bars closer to failure by the M 6.4 shock. In other words, the 4 July event stoked the fire for the 5 July magnitude 7.1 earthquake. This large stress jump very likely played a role in the triggering of the second event. In fact, it would not be incorrect to say that the M 7.1 was an unusually large aftershock of the M 6.4, rather than the M 6.4 being a foreshock of the M 7.1.

    3
    Coulomb stress changes on nearby faults, as a result of the 4 July 2019 M=6.4 earthquake near Ridgecrest. The approximate location of the 5 July M=7.1 earthquake is indicated by the purple star, near the northwesterly extension of the fault that ruptured on the 4th of July. Stress in the region of the M=7.1 event was increased by roughly 2 bars following the M=6.4 earthquake.

    Aftershocks Propagating Towards the Garlock Fault

    Seismicity between the M=7.1 at 8:19pm and midnight (local) has continued to the northwest and southeast. At the time of writing, 12:10am (local) the closest aftershock is within a few kilometers of the nearby Garlock Fault, which runs east-west between the Eastern California Shear Zone and the San Andreas Fault. Changes in stress on this major fault can have major implications for the nearby city of Los Angeles, and so will be closely monitored in the coming days. At this time, the USGS has forecasted that in the next week there is only a 9% chance of an aftershock which is equal to or larger than this M=7.1 event.

    References

    Hauksson, E., & Unruh, J. (2007). Regional tectonics of the Coso geothermal area along the intracontinental plate boundary in central eastern California: Three‐dimensional Vp and Vp/Vs models, spatial‐temporal seismicity patterns, and seismogenic deformation. Journal of Geophysical Research: Solid Earth, 112(B6).

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

    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 10:15 am on June 3, 2019 Permalink | Reply
    Tags: "El Salvador Earthquake: A Moderate Event in An Area of Extreme Seismic Risk", , , Earthquakes, , ,   

    From temblor: “El Salvador Earthquake: A Moderate Event in An Area of Extreme Seismic Risk” 

    1

    From temblor

    Posted on June 1, 2019 by Tiegan Hobbs
    Tiegan Hobbs, Ph.D., Postdoctoral Hazard Scientist (@THobbsGeo), and Ross S. Stein, Ph.D., Temblor, Inc.

    Because of its offshore location and moderate depth, Thursday’s shock did little damage. But many indications suggest that El Salvador will not stay so lucky for long. This event also highlights the increasing number of large extensional earthquakes: a global trend with important hazard implications.

    1
    A photo by Twitter user Daniel (@dfvegacom) showing the calm after the earthquake in El Salvador.

    At 03:03 am local time on Thursday morning, a strong earthquake ruptured off the west coast of El Salvador on the Pacific side of Central America. It was felt in southern Mexico, Guatemala, Honduras, Nicaragua, and Costa Rica, with a maximum reported intensity of about Level VI (strong shaking). The quake awakened many residents of the nearby city of La Libertad, less than an hour’s drive south of the capital city of San Salvador. But fortunately, the shaking is likely to damage only poorly built structures. Because of its moderate depth and offshore location, no tsunami was produced and little liquefaction or land-sliding is expected.

    2
    Thursday’s M 6.6 earthquake just off the coast of El Salvador was felt in surrounding countries: Mexico, Guatemala, Nicaragua, and Costa Rica.

    Waiting For El Salvador’s ‘Big One’ in the Red Zone

    While this event has no reported damage or injuries so far, El Salvador has among the highest seismic risks in the world. What does that mean, exactly? Hazard refers to the probability of earthquakes occurring, but risk refers to the likelihood of suffering losses from that hazardous event. Both El Salvador and Guatemala are recognized by the Global Earthquake Model Foundation as having a very high potential for losses due to a high likelihood of earthquakes occurring compounded by buildings and population centers that are highly susceptible to damage. So, this week’s earthquake was a gentle reminder of what could be in store for this small country.

    3
    The Global Earthquake Model Foundation assesses seismic risk around the world. El Salvador and Guatemala are both ominously high. (Silva et al., 2018)

    Two Deep Tensional Earthquakes in One Week

    As with the M=8.0 Peru earthquake from earlier this week, Thursday’s M=6.6 El Salvador earthquake was also a relatively deep tensional rupture. That means it occurs within the subducting slab, rather than on the interface between the slab and the over-riding continental plate. In this part of Central America, tensional events occur relatively frequently at this depth range (Correa-Mora et al., 2009). This includes a M=7.3 in 1982 and M=7.7 in 2001, which, combined, killed almost 2,000 people.

    Conflicting views of seismic hazard in Central America

    Although the GEM model and the Global Earthquake Activity Rate model (Bird et al., 2015), used by Temblor and shown in the first figure, both suggest high risk for El Salvador and Guatemala, Correa-Mora et al., (2009) argue that the subduction zone in this region may be too ‘weak’ (slippery) to generate large megathrust earthquakes. These are the kinds of events that are usually associated with great damage, and which can generate tsunami if they occur near the ocean floor. Correa-Mora and coauthors suggested that although there is a great deal of energy being released through earthquakes in the subduction zone region here, they are probably mostly from these tensional events. Nevertheless, earthquakes can be deadly regardless of their mechanism. The 1556 Huaxian earthquake in China occurred in an extensional rift environment, and yet it is the single deadliest earthquake on record, claiming 830,000 lives (Liu et al., 2011).

    Is the Rate of Large Global Tensional Earthquakes Growing?

    In addition to this week’s two major extensional (also called ‘normal’ or tensional) earthquakes, the last couple of years have seen other strong tensional events: the September 2017 M=7.1 Puebla earthquake in Mexico City, the November 2018 M=7.1 Anchorage earthquake in Alaska, and the February 2019 M=7.5 Ecuador earthquake. But is the apparent increase in extensional events real?

    4
    A map of tensional earthquakes with magnitude 7 and above, since 2005. They are distributed mainly in the ‘Ring of Fire, around the Pacific Ocean. Mapped using GeoMapApp.

    Generally speaking, we detect more earthquakes with time because networks, detection algorithms, and computing power are all improving. However, the number of large extensional events appears to increase with time at a greater rate than either thrust events or combined thrust and strike-slip events. The rate of increase is 0.01 magnitude units per year when normalized to all non-extensional earthquakes, and 0.02 when compared to only thrust events. This means that (1) there are more large tensional earthquakes than there were before, and (2) the occurrence of thrust events is actually decreasing slightly.

    6
    9

    The proportion of normal events is increasing with time. The ratio of extensional events to all other types of events (top) and to only thrust events (bottom), inclusive from 1976-2018 (Global CMT Project). Only M>7 earthquakes considered. The lines show a linear regression (fitting), with the corresponding equations and regression coefficients in the top left. A clear upward trend is observed, although a larger increase is occurring relative to thrust events. This means that the rate of large thrust events is actually decreasing with time.

    It’s possible that, because extensional earthquakes are sometimes quite deep, this apparent increased frequency of extensional events is just due to improved seismic networks. Additional work will be required to determine how compelling this result is. However, if it is real then it is astounding! These events occur because the subducting slab is being pulled apart as it is dragged into the mantle by suction. Is that suction force increasing with time, or does it oscillate? We know that great megathrust earthquakes (Ben-Naim et al., 2013) and strike-slip events (Pollitz et al., 2012) can tend to be clustered in time – perhaps the same is true for extensional intraslab events?

    Aftershocks in Unexpected Places

    7
    The initial aftershocks of the M=6.6 event lie 30-40 km southwest of the mainshock.

    Although Thursday’s M=6.6 earthquake off El Salvador was too far away to have been caused by Sunday’s M=8.0 event in Peru, the El Salvador event did produce its own remarkable aftershock sequence. Early aftershocks are concentrated to the southwest of the mainshock, roughly 30 km away, at a depth of about 35 km. Usually, aftershocks are distributed around the edge of the region that slipped during the mainshock, rather than being clustered in only one direction. This may be due to the rupture propagating (unzipping) towards the southwest, concentrating seismic energy in that direction, or possibly related to a tear or bump in the subducting slab that makes this region more susceptible. By studying cases like this one, scientists can better understand where and when aftershocks will strike in the aftermath of much larger earthquakes.

    References

    Ben‐Naim, E., Daub, E. G., & Johnson, P. A. (2013). Recurrence statistics of great earthquakes. Geophysical Research Letters, 40(12), 3021-3025.

    Bird, P., Jackson, D. D., Kagan, Y. Y., Kreemer, C. & Stein, R. S. (2015). GEAR1: A Global Earthquake Activity Rate Model Constructed from Geodetic Strain Rates and Smoothed Seismicity. Bull Seis. Soc. Am.105(5), 2538-2554.

    Correa-Mora, F., DeMets, C., Alvarado, D., Turner, H. L., Mattioli, G., Hernandez, D., … & Tenorio, C. (2009). GPS-derived coupling estimates for the Central America subduction zone and volcanic arc faults: El Salvador, Honduras and Nicaragua. Geophysical Journal International, 179(3), 1279-1291.

    Liu, M., Stein, S., & Wang, H. (2011). 2000 years of migrating earthquakes in North China: How earthquakes in midcontinents differ from those at plate boundaries. Lithosphere, 3(2), 128-132.

    Pollitz, F. F., Stein, R. S., Sevilgen, V., & Bürgmann, R. (2012). The 11 April 2012 east Indian Ocean earthquake triggered large aftershocks worldwide. Nature, 490(7419), 250.

    V. Silva, D. Amo-Oduro, A. Calderon, J. Dabbeek, V. Despotaki, L. Martins, A. Rao, M. Simionato, D. Viganò, C. Yepes, A. Acevedo, N. Horspool, H. Crowley, K. Jaiswal, M. Journeay, M. Pittore (2018). Global Earthquake Model (GEM) Seismic Risk Map (version 2018.1). DOI: 10.13117/GEM-GLOBAL-SEISMIC-RISK-MAP-2018.1, https://maps.openquake.org/map/global-seismic-risk-map/

    GEM Profile for El Salvador: https://downloads.openquake.org/countryprofiles/SLV.pdf

    USGS Event Pages

    https://earthquake.usgs.gov/earthquakes/eventpage/us70003t2n

    https://earthquake.usgs.gov/earthquakes/eventpage/us2000ar20/

    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 10:42 am on May 24, 2019 Permalink | Reply
    Tags: "Monitoring Haiti’s Quakes with Raspberry Shake", , , , Earthquakes, ,   

    From Eos: “Monitoring Haiti’s Quakes with Raspberry Shake” 

    From AGU
    Eos news bloc

    From Eos

    17 May 2019
    By Eric Calais, Dominique Boisson, Steeve Symithe, Roberte Momplaisir, Claude Prépetit, Sophia Ulysse, Guy Philippe Etienne, Françoise Courboulex, Anne Deschamps, Tony Monfret, Jean-Paul Ampuero, Bernard Mercier de Lépinay, Valérie Clouard, Rémy Bossu, Laure Fallou, and Etienne Bertrand

    1
    A woman displays a Raspberry Shake seismometer. Poor-quality construction, typical of many neighborhoods in Haiti, is visible in the background. A pilot project to create a network of these personal seismometers across Haiti aims not only to provide earthquake data but also to involve citizens in earthquake awareness and hazard mitigation efforts. Credit: E. Calais

    On 12 January 2010, a devastating earthquake put Haiti on the map for many of us who were unaware of the recurrent difficulties that the country has endured over the past decades. The earthquake claimed more than 200,000 lives, and the damage amounted to about $11 billion, close to 100% of the country’s gross domestic product.

    Before the earthquake, Haiti had no seismic network, no in-country seismologist, no active fault map, no seismic hazard map, no microzonation, and no building code. The national seismic network that has emerged since then currently consists of 10 broadband stations (Figure 1) [Seismological Research Letters ], operated and maintained by Haiti’s Bureau of Mines and Energy (BME). Although this network was a significant step in the right direction, it has not proved to be a panacea.

    2
    Fig. 1. Seismic stations in Haiti (symbols) and seismic activity as reported by the U.S. Geological Survey (white circles) from August 1946 to 14 January 2019. Natural Resources Canada (NRCan) broadband station PAPH (red circle), based in Port-au-Prince, is usually operational. The nine Raspberry Shake stations shown on this map (with their code names) were installed in January 2019 and were operational as of 15 February. The yellow star east of Port-au-Prince indicates the location of the M3.1 earthquake shown in Figure 3. Stations RE7D0, RE87E, and R2ABA, which use Wi-Fi to connect to the Internet, are not observing the radio frequency interference noted by some RS hosts elsewhere who also use Wi-Fi to connect to the Internet. BME is Haiti’s Bureau of Mines and Energy, which operates seismic instruments from two manufacturing companies.

    On 6 October 2018, a magnitude 5.9 earthquake struck northwestern Haiti, causing 17 fatalities and significant damage in the larger cities of the epicentral area. Only one seismic station was operating at the time, a situation that has persisted for several years now. In spite of its continued efforts, it is difficult for the BME to overcome the chronic lack of resources—financial and human—necessary to maintain such a high-technology system.

    This is where Raspberry Shake (RS) comes into play [Anthony et al., 2018 (Seismological Research Letters)]. This organization, founded using a Kickstarter campaign in 2016, provides affordable “personal seismometers” powered by small Raspberry Pi computers. The low cost of an RS station and the ease of installation and maintenance make it possible to imagine a situation in which perhaps as many as 100 citizens, businesses, or schools throughout Haiti would host an RS station.

    To do more than just imagine, we began a pilot project last January, purchasing and deploying nine one-component vertical velocimeters (RS1D) throughout Haiti (Figure 1), four of them additionally equipped with 3-D accelerometers (RS4D). Except for one station located at the BME, all RS hosts are private homes or hotels. We selected these hosts from people whom we knew had quasi-continuous Internet access and electricity, the latter being a major issue in Haiti. This initiative is similar to the Quake Catcher Network [see below] [Cochran et al., 2009 (Seismological Research Letters)], although the latter uses only accelerometers.

    Overcoming Limited Resources

    As a result of resource limitations, seismologists in Haiti are able to provide only limited information to the public or to decision-makers when earthquakes are felt. This reinforces the ill-founded perception that seismic monitoring is of little value, and it keeps the population in the dark about seismic hazard. As a result, citizens and businesses do little to protect themselves from future large events. The lack of reliable information also provides ground for fake seismonews, including the notion that earthquake prediction has already been around for years so that earthquake monitoring is irrelevant.

    Interestingly, however, the public demands reliable information about earthquakes and tsunamis and their associated risks. They ask questions, want to be informed, and want to know how to prepare. Some would even like to be able to help improve earthquake knowledge in Haiti.

    A citizen’s network of small, affordable seismic stations could be a starting place for providing this information. Even though RS instruments would most likely be concentrated in major cities, their redundancy would alleviate inevitable maintenance issues at any single station. Such a network would improve the ability of the Haiti seismic network to detect small-magnitude earthquakes on a continuous basis, resulting in a better understanding of earthquake distribution and fault behavior. In addition, installing seismometers in people’s homes may be a way to initiate a conversation with the population to promote a culture of earthquake safety.

    Setting Up the Network

    4
    Raspberry Shake setup at station R897D in Jacmel (see Figure 1) uses an RS1D instrument located on the first floor of a public notary’s office, under “made-on-the-spot” wooden protection. The RS station is connected to secure power and to the Internet through an Ethernet cable to the router visible on the windowsill. From left to right are Berthony (technician from the Haiti Bureau of Mines and Energy); Mrs. Beaulieu, who hosts the station; and authors Eric Calais and Steeve Symithe. Credit: E. Calais

    We set about creating our RS network by simply laying an RS instrument on the floor of the quietest first-story room we could find at each location. We connected them to power and Internet utilities, in six cases directly to the router via an Ethernet cable and in three cases via Wi-Fi. We made it clear to the hosts that the RS stations would use very little power and Internet bandwidth but that they should contact us if they suspected any issue. We also told them that they were free to disconnect the RS in case of a problem.

    Several hosts asked whether their RS could serve to predict earthquakes or whether they would sound an alarm if seismic waves were coming. We made it very clear that this was not the case and explained that we were mostly interested in the smaller earthquakes: the ones they never feel but that occur every day.

    “What? There are earthquakes every day in Haiti?” was a common reaction. Yes, indeed, we told our hosts, and knowing where and how big the small quakes are tells us a lot about the future large ones. Many hosts asked how they could see the information. We showed them how to view the helicorder (which records data from the seismometer) from their smartphone or computer on their local network, but often, they were not impressed with the displays. Helicorder output is indeed difficult to read because most squiggles are not earthquakes. Clearly, we need to do more work on how to provide relevant and useful information to RS station hosts.

    First Observations

    Three weeks after the installation of the first RS, we could already make a few observations that will be useful for the next phase of our project and, we hope, for other similar projects elsewhere.

    We have detected many events that occurred less than 100 kilometers from this first RS station. The first one (Figure 2), recorded on 13 January 2019, was later located by the seismological network of the Dominican Republic, which quoted its magnitude as 3.1. We also recorded a sequence of four events in northwestern Haiti the day after we installed another station; these events were not reported by any regional seismic network. Regional events show up very well too, for example, the M5.3 earthquake that struck the Dominican Republic on 4 February 2019. Even the P wave and S wave arrivals of teleseismic (distant) events are recorded, including an M5.6 earthquake that occurred in Colombia on 26 January 2019.

    5
    Fig. 2. Station R30E2, located in downtown Pétion-Ville, produced Haiti’s first Raspberry Shake station recording of a local earthquake on 13 January 2019. This event was not reported by Haiti’s national seismic network, but it was later reported by the Dominican Republic seismic network as an M3.1 event (yellow star in Figure 1) along the Enriquillo–Presqu’île du Sud fault close to the border between Haiti and the Dominican Republic.

    Noise levels are, of course, very different from station to station, unless tight seismological prescriptions are enforced. However, that is not the point of using low-cost RS stations at individual homes, businesses, or schools. Our hope is that the redundancy of RS stations within a small footprint—a city—will suffice to ensure the availability of enough reliable data. This remains to be investigated in a quantitative manner as more stations come online.

    We noticed that reliability and continuity of service are an issue, even though we tried our best to place the RS instruments at locations with continuous power and reliable Internet. One RS station host wanted to negotiate communication costs and, after a few days, apparently disconnected his station. Another station, located in a power-secure part of Port-au-Prince that had not previously needed power backup, is now experiencing regular blackouts. This underscores the importance of observation redundancy, with many stations at short distances from each other, because one never knows which one will have an issue and stop operating when an interesting earthquake shows up.

    A Work in Progress

    We were positively impressed by the response of civil society members and the private sector to this initiative. However, to gain the support of civil society, it is clear that we need to provide RS hosts with personalized information, such as “your RS instrument detected an earthquake of magnitude 2.5 located 50 kilometers away, in the area of….” A smartphone application would be a great way to provide this information in quasi-real time and keep station hosts engaged. It could also serve to broadcast information on earthquake preparedness and hence use the (fortunately long!) time intervals between large earthquakes to educate and promote earthquake safety.

    With the lessons learned during this pilot experiment, our goal now is to push forward and engage the civil society and the private sectors—at least those entities that can afford continuous power and Internet—to be a bigger part of this project. Expanding the project would provide more RS stations and thus redundancy and continuity of service. It would also engage RS hosts in a project that puts them at the center of the information chain. RS hosts will become information providers to scientists rather than passive listeners to scarce and unintelligible information.

    It is our hope that as RS hosts and others become more aware of the earthquake issue, they will share information they will be privy to. We hope that they will become advocates for seismic monitoring, but more important, we hope that they will act to reduce seismic risk for themselves and their community.

    Acknowledgments

    This pilot activity is funded by the Interreg Caraibes/European Regional Development Fund (FEDER) program through the PREST (vers la Plateforme Régionale de Surveillance Tellurique du Futur) project, the Centre National de la Recherche Scientifique/French Institute for Research and Development (IRD) Risques Naturels program, and the Jeune Equipe Associée of the IRD. All data from the RS stations installed in Haiti are openly available via the Raspberry Shake International Federation of Digital Seismograph Networks (FDSN) web services. We thank Maurice Lamontagne and two anonymous reviewers for their constructive comments.

    References

    Anthony, R. E., et al. (2018), Do low‐cost seismographs perform well enough for your network? An overview of laboratory tests and field observations of the OSOP Raspberry Shake 4D, Seismol. Res. Lett., 90(1), 219–228, https://doi.org/10.1785/0220180251.

    Bent, A. L., et al. (2018), Real‐time seismic monitoring in Haiti and some applications, Seismol. Res. Lett., 89(2A), 407–415, https://doi.org/10.1785/0220170176.

    Cochran, E. S., et al. (2009), The Quake-Catcher Network: Citizen science expanding seismic horizons, Seismol. Res. Lett., 80(1), 26–30, https://doi.org/10.1785/gssrl.80.1.26.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

    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 8:16 am on April 22, 2019 Permalink | Reply
    Tags: , Earthquakes, Hydrophones, MERMAIDs, ,   

    From Science Magazine: “These ocean floats can hear earthquakes, revealing mysterious structures deep inside Earth” 

    AAAS
    From Science Magazine

    Apr. 17, 2019
    Erik Stokstad

    1
    A MERMAID undergoes testing off Japan’s coast in 2018. ALEX BURKY/PRINCETON UNIVERSITY

    A versatile, low-cost way to study Earth’s interior from sea has yielded its first images and is scaling up. By deploying hydrophones inside neutrally buoyant floats that drift through the deep ocean, seismologists are detecting earthquakes that occur below the sea floor and using the signals to peer inside Earth in places where data have been lacking.

    In February, researchers reported that nine of these floats near Ecuador’s Galápagos Islands had helped trace a mantle plume—a column of hot rock rising from deep below the islands. Now, 18 floats searching for plumes under Tahiti have also recorded earthquakes, the team reported last week at the European Geosciences Union (EGU) meeting here. “It seems they’ve made a lot of progress,” says Barbara Romanowicz, a geophysicist at the University of California, Berkeley.

    The South Pacific fleet will grow this summer, says Frederik Simons, a seismologist at Princeton University who helped develop the floats, called MERMAIDs (mobile earthquake recorders in marine areas by independent divers). He envisions a global flotilla of thousands of these wandering devices, which could also be used to detect the sound of rain or whales, or outfitted with other environmental or biological sensors. “The goal is to instrument all the oceans.”

    For decades, geologists have placed seismometers on land to study how powerful, faraway earthquakes pass through Earth. Deep structures of different density, such as the cold slabs of ocean crust that sink into the mantle along subduction zones, can speed up or slow down seismic waves. By combining seismic information detected in various locations, researchers can map those structures, much like 3D x-ray scans of the human body. Upwelling plumes and other giant structures under the oceans are more mysterious, however. The reason is simple: There are far fewer seismometers on the ocean floor.

    Such instruments are expensive because they must be deployed and retrieved by research vessels. And sometimes they fail to surface after yearlong campaigns. More recently, scientists have begun to use fiber optic communication cables on the sea floor to detect quakes, but the approach is in its infancy.

    MERMAIDs are a cheap alternative. They drift at a depth of about 1500 meters, which minimizes background noise and lessens the energy needed for periodic ascents to transmit fresh data. Whenever a MERMAID’s hydrophone picks up a strong sound pulse, its computer evaluates whether that pressure wave likely originated from seafloor shaking. If so, the MERMAID surfaces within a few hours and sends the seismogram via satellite.

    The nine floats released near the Galápagos in 2014 gathered 719 seismograms in 2 years before their batteries ran out. Background noise, such as wind and rain at the ocean surface, drowned out some of the seismograms. But 80% were helpful in imaging a mantle plume some 300 kilometers wide and 1900 kilometers deep, the team described in February in Scientific Reports. The widely dispersed MERMAIDs sharpened the picture, compared with studies done with seismometers on the islands and in South America. “The paper demonstrates the potential of the methodology, but I think they need to figure out how to beat down the noise a little more,” Romanowicz says.

    Since that campaign, the MERMAID design was reworked by research engineer Yann Hello of Geoazur, a geoscience lab in Sophia Antipolis, France. He made them spherical and stronger, and tripled battery life. The floats now cost about $40,000, plus about $50 per month to transmit data. “The MERMAIDs are filling a need for a fairly inexpensive, flexible device” to monitor the oceans, says Martin Mai, a geophysicist at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia.

    Between June and September of 2018, 18 of these new MERMAIDs were scattered around Tahiti to explore the Pacific Superswell, an expanse of oddly elevated ocean crust, likely inflated by plumes. The plan is to illuminate this plumbing and find out whether multiple plumes stem from a single deep source. “It’s a pretty natural target,” says Catherine Rychert, a seismologist at the University of Southampton in the United Kingdom. “You’d need a lot of ocean bottom seismometers, a lot of ships, so having floats out there makes sense.”

    So far, the MERMAIDs have identified 258 earthquakes, Joel Simon, a graduate student at Princeton, told the EGU meeting. About 90% of those have also been detected by other seismometers around the world—an indication that the hydrophones are detecting informative earthquakes. Simon has also identified some shear waves, or S-waves, which arrive after the initial pressure waves of a quake and can provide clues to the mantle’s composition and temperature. “We never set out to get S-waves,” he said. “This is incredible.” S-waves can’t travel through water, so they are converted to pressure waves at the sea floor, which saps their energy and makes them hard to identify.

    In August, 28 more MERMAIDS will join the South Pacific fleet, two dozen of them bought by the Southern University of Science and Technology in Shenzhen, China. Heiner Igel, a geophysicist at Ludwig Maximilian University in Munich, Germany, cheers the expansion. “I would say drop them all over the oceans,” he says.

    See the full article here .


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    Stem Education Coalition

     
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