Tagged: temblor Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 9:22 am on June 30, 2020 Permalink | Reply
    Tags: , , Magnitude-5.9 quake is the latest and largest in Tokyo seismic swarm, temblor,   

    From temblor: “Magnitude-5.9 quake is the latest and largest in Tokyo seismic swarm” 

    1

    From temblor

    June 29, 2020
    Shinji Toda, Ph.D., International Research Institute for Disaster Science, Tohoku University
    Ross Stein, Ph.D., Temblor Inc.

    Six magnitude-5.0+ shocks have struck greater Tokyo since April 1st, part of a larger swarm that extends north to Hokkaido, at a rate that is about three times higher than normal.

    1
    The recent swarm shocks are shown as stars. Tokyo sits near the junction where three great tectonic plates, the Pacific, Philippine Sea, and Eurasia, meet.

    Tokyo’s seismic past and future

    Earthquakes have long accosted the residents of Tokyo. Most devastating was the magnitude-7.9 1923 Kanto earthquake that killed ~105,000 people, rupturing the megathrust along the Sagami trough. An even larger event struck in 1703. Modern Tokyo and its suburbs are home to one-quarter of Japan’s 127 million population.

    Tokyo is uniquely located where three tectonic plates converge, a setting known as a “triple-junction.” Both the Philippine Sea and Pacific plates are shoved, or subducted, beneath Tokyo, causing megathrust earthquakes on multiple plate interfaces, as well as shallow crustal quakes, and deep earthquakes within the subducting plates.

    2
    Cross section of seismicity (black dots) beneath Tokyo, which sits in the middle of the Kanto Plain. The Pacific plate (PAC) subducts beneath the Eurasian plate (EUR). We believe that a fragment of the Pacific plate is wedged between the underlying Pacific slab and the overlying Eurasia. Many small and some destructive earthquakes have occurred along the surfaces of the fragment. From Toda et al. (2008).

    To evaluate the seismic hazard, the Japanese government has regularly updated their estimates of large earthquake probabilities since it launched the Headquarters of Earthquake Research Promotion in 1995. The last report announced that the 30-year probability of magnitude-6.7+ quakes for the Tokyo metropolitan area is ~70%.

    The swarm so far

    The recent magnitude-5.0+ earthquakes near metropolitan Tokyo emphasize the high risk of devastating earthquakes. From 1 April 2020 to 28 June, six earthquakes over magnitude-5.0 occurred within ~62 miles (100 kilometers) from the downtown Tokyo (lon. 139.750°/lat. 35.683°), which is two times higher than annual average rate of magnitude-5.0+ quakes since 1950. If this high rate remains, 14 quakes would strike Tokyo by the end of 2020.

    3
    Six magnitude-5.0+ earthquakes have struck in the Tokyo metro region since 1 April, 2020. The five quakes closest to Tokyo are show here as red stars, along with the epicenters of past earthquakes (blue dots).

    The swarm quakes (red dots) in the above map are occurring in much the same location as past events (blue dots), indicating that the same faults that have slipped in the past are continuing to slip during the swarm. But now, these faults have been activated at a higher rate. We term the current rapid rate of earthquakes a ‘mild swarm,’ because it exceeds the range of natural fluctuation of rate rates. The only comparable period was the year after the 2011 magnitude-9.0 Tohoku earthquake, which transferred a large and sudden pulse of stress to the Kanto region (Ishibe et al., 2011; Toda and Stein, 2013).

    Good news, bad news

    We do not know why the rate of magnitude-5.0+ shocks is increased or whether the ongoing mild swarm could be precursory to a larger catastrophic event. However, the simplest and perhaps most prudent interpretation is that the higher the rate of moderate size quakes accompanies a higher probability of large ones. This assumes that the ratio of small to large quakes has not changed, which, as far as we can tell, is the case.

    A counterargument to our interpretation signals a higher hazard (a higher chance of large events) would be that the swarm quakes indicate that ‘aseismic’ creep is also occurring, as has been recorded off the Boso Peninsula (Uchida and Matsuzawa, 2013). If the magnitude-5.0+ quakes accompany accelerated fault creep, that creep could reduce fault stress. This might then lower the probability of large earthquakes, as advocated by Sommerville (2014).

    4
    The 1855 Ansei-Edo shock destroyed former Tokyo. Its inferred location and depth coincides with one of the recent magnitude-5.0+ swarm earthquakes. (From Grunewald and Stein, 2006).

    But there is a problem with this interpretation. Several of the swarm quakes struck at a location and depth similar to that of the magnitude~7.2 Ansei-Edo earthquake, which destroyed Edo (former Tokyo) in 1855. That means that the faults beneath Tokyo cannot exclusively creep accompanied by harmless magnitude-5.0 shocks; instead, those faults must also store enough stress to rupture in strong quakes, and so could again. Even if half the inferred slip rate of 1.7 inches per year (~40 millimeters per year) for the slab fragment with respect to the Pacific plate (Toda et al, 2008) is seismic, enough stress has accumulated since 1855 for 9.8 feet (3 meters) of slip, or enough for another deep magnitude-7.2 event.

    5
    Here is the earthquake forecast issued by Temblor to its commercial clients on 1 June 2020. The impact of the 2011 magnitude-9.0 Tohoku shock, as well as all other magnitude-6.5+ shocks are incorporated into the forecast. Red-yellow sites are expected to have the highest rate of magnitude-5.0 shocks. The 25 Jun 2020 event is consistent with this forecast.

    Even in the time of COVID, we must prepare for quakes

    Even while Japan continues to battle the coronavirus pandemic, as long as the swarm persists, the Japanese should make provisions for the possibility of large earthquakes. Given the great number of people in the Tokyo metropolitan area, we need to plan for shelters that are safe for both natural disasters and coronavirus infection, a daunting prospect.

    Acknowledgements

    We used the JMA and NIED hypocenter data to analyze seismicity with a software package ZMAP (Wiemer, 2001).

    Further Reading

    Grunewald, E., and R. S. Stein (2006), A new 1649-1884 catalog of destructive earthquakes near Tokyo and implications for the long-term seismic process, J. Geophys. Res., 111, doi:10.1029/2005JB004059.

    Headquarters for Earthquake Research Promotion, 2014, Long-term seismic hazard estimates for the regions along the Sagami trough (updated), https://www.jishin.go.jp/main/chousa/kaikou_pdf/sagami_2.pdf. (in Japanese)

    Ishibe, T., K. Shimazaki, K. Satake, and H. Tsuruoka, Change in seismicity beneath the Tokyo metropolitan area due to the 2011 off the Pacific coast of Tohoku Earthquake, Earth Planets Space, 63, 731–735, 201, doi:10.5047/eps.2011.06.001.

    Sommerville, Paul (2014), A post-Tohoku earthquake review of earthquake probabilities in the Southern Kanto District, Japan, Geoscience Lett., 1, 10, doi.org/10.1186/2196-4092-1-10.

    Toda, S., R. S. Stein, S. H. Kirby, and S. B. Bozkurt (2008), A slab fragment wedged under Tokyo and its tectonic and seismic implications, Nature Geoscience, 1, 771-776, doi:10.1038.ngeo318.

    Toda, S. and R. S. Stein, 2013, The 2011 M=9.0 Tohoku oki earthquake more than doubled the probability of large shocks beneath Tokyo, Geophys. Res. Lett., 40, 2562-2566, doi.org/10.1002/grl.50524.

    Uchida N, and T. Matsuzawa, 2013, Pre- and post-seismic slow slip surrounding the 2011 Tohoku-Oki earthquake rupture. Earth Planet Sci. Lett., 374, 81–91, doi: 10.1016/j.epsl.2013.05.021.

    Wiemer, S., 2001, A software package to analyse seismicity: ZMAP, Seismol. Res. Lett. 72, 373– 382, doi.org/10.1785/gssrl.72.3.373.

    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 4:42 pm on June 25, 2020 Permalink | Reply
    Tags: "La Crucecita earthquake illustrates quake risk in México", , , , , , temblor   

    From temblor: “La Crucecita earthquake illustrates quake risk in México” 

    1

    From temblor

    June 25, 2020
    By Aaron A. Velasco, University of Texas at El Paso, Xyoli Pérez-Campos, Servicio Sismológico Nacional (SSN), Instituto de Geofísica, Universidad Nacional Autónoma de México, Allen Husker, Department of Geophysics, Instituto de Geofísica, Universidad Nacional Autónoma de México, Marianne S. Karplus, University of Texas at El Paso, Hector Gonzalez-Huizar, Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, Solymar Ayala Cortez, University of Texas at El Paso.

    On June 23, 2010 at about 10:30 am local time, a large magnitude-7.4 earthquake struck the Pacific coast of Oaxaca, México, as reported by the Servicio Sismológico Nacional (SSN), UNAM, the national seismic authority in México. Strong shaking reached nearby cities, such as La Crucecita, Juchitán, El Espinal and Asunción Ixtaltepec — cities that remained heavily damaged from the magnitude-8.2 Tehuantepec quake in 2017.

    1
    Cracks in the sand on a beach near La Crucecita taken two hours after the earthquake. A laguna is to the left in the photo and the ocean to the right. The cracks outline the laguna and result from infiltration of water from the laguna due to the earthquake. Credit: Ericka Alinne Solano

    Tuesday’s earthquake triggered the early warning system in México City, over 500 km away from the epicenter. Residents received an earthquake alert almost two minutes prior to the arrival of the seismic waves that shook buildings throughout the city. In the state of Oaxaca, at least six people were killed by the earthquake. Seven hospitals were damaged in different towns and in some of these, patients were evacuated. Reports of a small tsunami have been confirmed and initial estimates show that the nearby coast was uplifted about 1.6 feet (0.5 meters). In the 12 hours following the earthquake, the SSN had reported more than 1200 aftershocks, the largest — with a magnitude of 5.5 — occurred about 11 hours after the mainshock.

    2
    Map showing the epicenter of Tuesday’s La Crucecita earthquake from the Servicio Sismológico Nacional (SSN), and two other major earthquakes in the region. The Middle American Trench and the Tehuantepec Ridge are significant ocean floor features.

    Tectonic plate boundaries produce big earthquakes

    In this region, the Cocos Plate subducts beneath the North American Plate, creating a seismic and volcanic belt along the Pacific coast of Mexico. Tuesday’s earthquake occurred near this interface along the tectonic plate boundary known as the Middle American Trench, just offshore at a shallow depth 13.7 miles (22.6 kilometers) according to SSN. Preliminary estimates by the SSN and the United States Geological Survey show the earthquake occurred on a thrust fault oriented west-northwest, which is consistent with motion along this plate boundary interface.

    A complex plate boundary

    A number of factors contribute to the complex seismicity observed in this region. The Tehuantepec ridge, a remnant fracture zone related to the East Pacific spreading center, is being actively subducted beneath the North American Plate about 71.5 miles (115 kilometers) from Tuesday’s epicenter. This bathymetric high may play a role in the tectonic complexities of the region, as nearby the angle of subduction of the Cocos plate changes from shallow in the northwest to steep in the southeast.

    Studies in the region show that slow-slip events — where an earthquake’s worth of energy and fault slip is released over a period of weeks to months — and weak vibration of the Earth’s crust occur along parts of this subduction zone. Seismologists are still trying to figure out whether these slow slip events could trigger large earthquakes.

    Distant earthquakes cause shaking in Mexico City

    Near the epicenter of a large earthquake, the shaking can be very strong, generating significant damage, as was observed in La Crucecita and other cities closest to the epicenter. Generally, seismic waves decrease in amplitude with distance from an earthquake epicenter and shaking diminishes. However, the soft sediments that comprise the México City basin act to slow and amplify these incoming waves. This, and the long duration of shaking created by distant but strong surface waves, can cause significant shaking in México City.

    This earthquake was felt strongly in México City but fortunately, did not result in significant damage. The city has not been so lucky in the past and has suffered damage from distant earthquakes such as the 1985 magnitude-8.1 earthquake and the Morelos-Puebla magnitude-7.1 earthquake in 2017, 400 km and 50 km away from city center, respectively.

    2017 Tehuantepec earthquake

    On September 7, 2017, the magnitude-8.2 Tehuantepec earthquake struck offshore, around 125 miles (200 kilometers) southeast of the Tuesday’s epicenter. Unlike the thrust motion observed in this quake, the Tehuantepec earthquake ruptured the downgoing Cocos plate along a high-angle normal fault at ~28 miles (~45 kilometers) depth. The rupture propagated northwest at a relatively high velocity 2.1-2.24 miles per second (3.4-3.6 kilometers per second). Normal faults generally accommodate tensional force in Earth’s crust, rather than the compressional force expected when two tectonic plates are being pushed together in a subduction zone.

    Aftershocks from a large earthquake usually outline the section of the main fault that ruptured because stress changes related to the main shock are often strongest closest to the area of the fault that ruptured. These stress changes cause a trickle of aftershocks in this area following a quake. The complexity of the Tehuantepec earthquake rupture is highlighted by the aftershock locations.

    3
    Epicenters from the SSN catalog are plotted for September to October 2017, highlighting seismicity immediately following the Tehuantepec earthquake. The different colors represent different depths of the earthquakes. Aftershocks were generally shallow closer to the main shock location and deeper inland, following the subduction interface. However, north of the Tehuantepec ridge a region of shallow inland aftershocks shows that there is additional complexity in the faults beneath the surface.

    The La Crucecita earthquake occurred adjacent to the shallow, northern aftershocks of the Tehuantepec earthquake. This quake extends the seismically active region along the plate interface evident in the aftershocks from the Tehuantepec quake.

    If the two earthquakes are related, the exact triggering mechanism must be further investigated, as earthquakes can be linked through the type of stresses that they create. For example, permanent deformation created by movement along a fault can increase or decrease stresses on adjacent faults, affecting the likelihood of future earthquakes. This stress usually diminishes within two fault lengths of a rupture. The Tehuantepec earthquake rupture length was approximately 75-125 miles (~120-200 kilometers), which could increase stress within about 250 miles (400 kilometers) of the epicenter. Preliminary analysis of the stress generated during the Tehuantepec earthquake shows an increase in the surrounding regions, including near the epicenter of the June 23 earthquake.

    4
    Preliminary stress calculations from movement of the fault that ruptured during the Tehuantepec earthquake. The increase in stress in the region around the La Crucecita earthquake could have triggered this earthquake.

    Further Reading

    Husker, A., Frank, W. B., Gonzalez, G., Avila, L., Kostoglodov, V., & Kazachkina, E. (2019). Characteristic Tectonic Tremor Activity Observed Over Multiple Slow Slip Cycles in the Mexican Subduction Zone. Journal of Geophysical Research: Solid Earth, 124(1), 599–608. https://doi.org/10.1029/2018JB016517

    Manzo, D. (2020), La Jornada, accessed 23 June 2020, https://www.jornada.com.mx/ultimas/politica/2020/06/23/sismo-de-7-5-deja-cinco-muertos-y-danos-a-viviendas-en-oaxaca-2101.html

    Gonzalez-Huizar, H. (2019) La Olimpiada XXIV de Ciencias de la Tierra: Los Grandes Terremotos de México, GEOS, 39(1).

    Perez-Campos, X., & Clayton, R. W. (2014). Interaction of Cocos and Rivera plates with the upper-mantle transition zone underneath central México. Geophysical Journal International, 197(3), 1763–1769. https://doi.org/10.1093/gji/ggu087

    Suárez, G., Santoyo, M. A., Hjorleifsdottir, V., Iglesias, A., Villafuerte, C., & Cruz-Atienza, V. M. (2019). Large scale lithospheric detachment of the downgoing Cocos plate: The 8 September 2017 earthquake (M 8.2). Earth and Planetary Science Letters, 509, 9–14. https://doi.org/10.1016/j.epsl.2018.12.018

    SSN (2020). Reporte especial: Sismo del 23 de junio de 2020, costa de Oaxaca (M 7.5). Servicio Sismológico Nacional, Instituto de Geofísica, Universidad Nacional Autónoma de México, México. URL: http://www.ssn.unam.mx

    Toda, S., & Stein, R. S. (2015). 2014 M w 6.0 South Napa Earthquake Triggered Exotic Seismic Clusters near Several Major Faults. Seismological Research Letters, 86(6), 1593–1602. https://doi.org/10.1785/0220150102

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:38 am on June 19, 2020 Permalink | Reply
    Tags: "Magnitude-5.9 quake strikes the eastern end of the North Anatolian Fault", , , , , temblor   

    From temblor: “Magnitude-5.9 quake strikes the eastern end of the North Anatolian Fault” 

    1

    From temblor

    June 18, 2020
    Haluk Eyidoğan, Ph.D., Professor of Seismology, Istanbul Technical University

    A moderate earthquake struck the Bingöl province in eastern Turkey on Sunday. The quake occurred at the intersection between two major faults in the region along a right-lateral strand of the North Anatolian Fault.

    On June 14, 2020 (14:26 UTC) in the province of Bingöl in eastern Turkey, near Kaynarpinar village (39.3495 N, 40.7350 E), a strong earthquake occurred. According to Turkish authorities, the shallow — 3.1 mile (5 kilometer) — deep quake registered as a magnitude-5.8. The European Mediterranean Seismic Centre (EMSC) reports it as a magnitude-5.9.

    1
    The location of the 14 June 2020 earthquake and other notable quakes in the region.

    The number of buildings damaged in the quake is not currently known, but there are reports of significant damage to mudbrick masonry structures and also to a small number of reinforced concrete structures. Official statements report at least one fatality and several people injured.

    Junction of the North Anatolian and East Anatolian Faults

    The earthquake ocurred where the North Anatolian Fault and the East Anatolian Fault meet. This junction exhibits a rather complicated network of faults of different length that cross one another. Depending on the orientation and magnitude of stress imparted by this earthquake on the faults in the region, I expect that aftershock activity may be prolonged.

    Elmali Fault a likely source

    The earthquake seems to have struck on the right-lateral strike-slip Elmalı Fault, a 27-kilometer-long branch of the North Anatolian Fault, based on the latest official active fault map in Turkey. Slip on this fault caused a magnitude-6.9 earthquake on August 17, 1949. Regions of high damage correlate to the location of the Elmalı Fault, further suggesting this is the structure that ruptured. The locations of large and moderate magnitude earthquakes are often revised by scientists after review of available data. After the location of this earthquake is revised and finalized, the quake’s relationship with the 40-kilometer-long Kargıpazar Fault, parallel to the Elmalı Fault, will be better understood.

    1:1 250 000 Scale Active Fault Map Of Turkey

    This map is a guide document which shows the geographic distribution and general characteristics of the active faults of the Turkish mainland. It provides active fault information at a 1:1,250,000 scale for the country. It is published with accompanying explanatory textbook. It does not provide all data to be used in analytical assessments and applications. Click for the larger map view.

    Cite this map as follows:

    Emre, Ö., Duman, T.Y., Özalp, S., Elmacı, H., Olgun, Ş. and Şaroğlu, F., 2013. Active Fault Map of Turkey with and Explanatory Text. General Directorate of Mineral Research and Exploration, Special Publication Series-30. Ankara-Turkey

    1

    After 250 years of quiet, is the Yedisu Fault now in play?

    The epicenter of the earthquake is located near the eastern end of the Yedisu Fault, one of the important segments of the North Anatolian Fault. The Yedisu Fault has not generated a strong earthquake in the last 250 years — since 1874, when a magnitude-5.8 quake struck — according to current records. Given the location of this week’s earthquake and the orientation of the fault that likely ruptured, I recommend calculating how much stress the 1874 earthquake — with a right strike-slip fault mechanism — loaded on Yedisu Fault. This analysis may inform futures estimates of earthquake hazard in the region.

    Further Reading

    Active Faults of Turkey, General Directorate of Mineral Research and Exploration (MTA), Ankara, Turkey.
    Duman, T.Y. & Emre, Ö., 2013. The East Anatolian Fault: geometry, segmentation and jog characteristics Geological Society, London, Special Publications, 372, 495-529.

    Eyidoğan, H., U. Güçlü, Z. Utku & E. Değirmenci, 1991. Türkiye büyük depremleri makro-sismik rehberi (1900-1988), İstanbul Teknik Üniversitesi, İstanbul, 199 pages.

    http://www.koeri.boun.edu.tr/sismo/2/latest-earthquakes/list-of-latest-events/

    https://www.emsc-csem.org/Earthquake/earthquake.php?id=867603#summary

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 1:18 pm on June 12, 2020 Permalink | Reply
    Tags: "Five Puget Sound cities likely to feel strong shaking in a megaquake", , temblor   

    From temblor: “Five Puget Sound cities likely to feel strong shaking in a megaquake” 

    1

    From temblor

    June 11, 2020
    Ian Stone, University of Washington

    Cascadia has experienced major earthquakes in the past. Should another occur today, the region’s cities would feel intense shaking — some more than others.

    Cascadia subduction zone

    Although Washington State’s Puget Sound has been shaken every few decades, damage in the region’s largest cities, including Seattle, Tacoma and Olympia, has only ever been modest.

    However, an enormous threat lurks just off the coast of the Pacific Northwest. Here, the Juan de Fuca tectonic plate is jammed beneath the North American plate at a rate of a few centimeters per year. The interface of the two plates is the Cascadia subduction zone, a fault that has generated magnitude-8.0+ earthquakes over intervals spanning many centuries. The region’s last major earthquake was in 1700, when an approximate magnitude-9.0 earthquake ruptured the full length of the fault, which extends from off the coast of Northern California to Vancouver Island in Canada.

    2
    The Cascadia subduction zone sits just offshore of the Pacific Northwest. Red shading indicates areas of possible slip on the fault during a magnitude-9.0 earthquake. Credit: USGS

    A repeat of the 1700 earthquake today would cause extensive damage throughout the Pacific Northwest. The risk is particularly high in the Puget Sound, where major population centers are growing directly in harm’s way.

    A geologic mystery is solved

    The 1700 quake occurred two centuries before seismometers were invented and widely installed. We therefore do not have direct measurements of how large the earthquake was. Magistrate records from Eastern Japan and Native American oral histories from the Pacific Northwest do, however, suggest a large wave of water swept through these regions around this time. It wasn’t until 20th century researchers compared these records with coastal geology that the source of this tsunami was identified: a magnitude-9.0 earthquake on the Cascadia subduction zone (Atwater et al., 2005; Satake et al., 2003; Ludwin et al., 2005).

    A disaster in the making

    Since the start of European settlement in the late 19th century, the population of the Pacific Northwest has grown into the millions, and the region is currently experiencing one of the largest population booms in the country. Within Washington State’s Puget Sound region, urbanization has transformed muddy tidal flats into the bustling port cities of Seattle, Tacoma and Olympia, which have rapidly grown into huge tech and manufacturing hubs. Most of this urbanization took place prior to the realization of the danger posed by a possible megathrust earthquake.

    Knowing how the 1700 event shook the region would provide valuable information about which areas need more preparation before the next great Cascadia earthquake. While there are not seismological recordings of the last Cascadia earthquake, seismologists can simulate ground shaking using information about the fault and observations from other subduction zone earthquakes. With these results, we can see which parts of the Puget Sound would experience the strongest shaking during a possible repeat of the 1700 quake.

    Simulated peak ground velocities from a magnitude-9.0 earthquake on the Cascadia Subduction Zone (taken from the results of Frankel et al., 2018 and Wirth et al., 2018) highlight differences in the effect of such an earthquake throughout the Puget Sound region. The peak ground velocity describes the maximum speed at which the ground moves during an earthquake and typically correlates well with felt shaking intensity ¬— and damage —during large earthquakes. As a point of comparison, a peak ground velocity of 1.1 miles per hour (0.5 meters/second) was strong enough to tip over train cars during the 1906 magnitude-7.0 San Francisco earthquake (Veeraraghavan et al., 2019).

    Since we do not know where the hypocenter was or the exact slip distribution for the 1700 earthquake, what’s shown in the map is the average peak ground velocity from thirty different rupture scenarios, each considering a different hypocenter and slip distribution. While the peak ground velocity for a city may change from one rupture scenario to another, the relative response between cities is often similar, since shaking is strongly influenced by geologic structure and fault location. Using these data, we can estimate which cities with a population greater than 50,000 in the Puget Sound region are expected to experience the strongest shaking.

    3

    These results might not be immediately intuitive. After all, Olympia, which is the closest of the cities to the megathrust fault, is estimated to experience the least severe shaking; at the same time, many cities on the east side of the Puget Sound — further away from the fault — experience much stronger shaking. This oddity may be attributed to the effect of sedimentary basins, which trap and amplify seismic waves. Shoreline sits near the middle of the Seattle Basin, which is why it is estimated to experience the strongest shaking, with a peak ground velocity around 1.6 miles per hour (0.7 meters/second). Cities with the lowest amount of estimated shaking are either located away from sedimentary basins or are further to the east. Topping this list are Olympia, Everett and Sammamish, all of which are estimated to experience a peak ground velocity around 0.7 miles per hour (0.3 meters/second).

    It is important to emphasize that when it comes to earthquake damage, the estimated shaking mapped above will only be part of the equation. Factors like construction quality and local soil conditions will play an important role in how much a structure is damaged. For instance, a well-built house on hard rock in a strong shaking area might fare better than a poorly built house on sand or artificial fill in a weak shaking area. The results presented here do not consider localized soil conditions, so shaking at a given location may end up being stronger (or weaker) than what is shown.

    It is also important to point out that the city with the “weakest” shaking in this analysis (Olympia) is still estimated to have a peak ground velocity near 0.7 miles per hour (0.3 meters/second), which is strong enough to be widely felt and cause modest localized damage.

    Preparing for the next earthquake

    When the subduction zone ruptures again, the earthquake will only be the start of the disaster. It is expected that a repeat of the 1700 earthquake would cripple infrastructure throughout the entire Pacific Northwest, and for many weeks following the disaster, citizens of the area will have to learn to live without access to fully functioning roads, water, electricity and sewage, according to the Cascadia Region Earthquake workgroup 2013 report. This is doubly true for more remote regions of Western Washington and Oregon.

    The estimated likelihood of another magnitude-9.0 earthquake on the Cascadia Subduction Zone over the next 50 years sits at around 15% (Goldfinger et al., 2017). The likelihood of a magnitude-8.0 or larger earthquake in the same time period, which would partially rupture the fault and still do a significant amount of damage, is around 40% (Goldfinger et al., 2012). Also consider that a magnitude-9.0 mainshock can produce an approximately magnitude-8.0 aftershock, as happened 30 min after the magnitude-9.0 Tohoku, Japan, megathrust earthquake in 2011.

    You can use the Temblor app to look at the impact of a magnitude-9.0 earthquake on your home, in terms of cost and repair time, in the Temblor app. Temblor finds your location, grabs information about your home from public databases and uses USGS, FEMA, and Washington Geological Survey data and models to estimate your own losses.

    It’s important that those living in the Pacific Northwest have a personal disaster plan. Emergency managers recommend having a cache of water and non-perishable foods that will sustain you and your family for up to fourteen days. Other suggestions on building an emergency plan may be found at the Washington Emergency Management website.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:59 am on May 17, 2020 Permalink | Reply
    Tags: "Magnitude-6.5 earthquake rattles Nevada and California", , , , temblor   

    From temblor: “Magnitude-6.5 earthquake rattles Nevada and California” 

    1

    From temblor

    May 15, 2020
    Alka Tripathy-Lang, PhD

    A shallow earthquake struck near the California-Nevada border in the early morning hours on May 15, 2020, waking people as far away as the Bay Area and Las Vegas.

    1
    A magnitude-6.5 quake struck a remote part of Nevada today (May 15, 2020), but was felt in the San Francisco Bay area, Bakersfield, and Las Vegas. Based on its aftershocks and focal mechanism, the event probably struck on an unnamed left-lateral fault. Credit: Temblor

    On May 15, 2020, at 4:03 a.m. local time, the desert area west of Tonopah, Nev., was rattled awake by a widely felt magnitude-6.5 earthquake. Nucleating at a depth of 1.7 miles (2.8 kilometers), this shallow temblor occurred on a nearly vertical fault surface where no matter which side of the fault you’re on, the other side moved to the left. Called a left-lateral strike-slip fault, it is similar to the fault that ruptured during the magnitude-6.4 Ridgecrest foreshock that struck approximately 170 miles (270 kilometers) to the south less than a year ago.

    Damage appeared to be minimal, with the Nevada Department of Transportation reporting minor pavement damage to a half-mile section of U.S. Highway 95.

    Earthquakes east of the Sierra Nevada

    As the Pacific Plate moves northwest relative to North America, much of that motion occurs on the famed San Andreas Fault. However, a significant component of the movement between these two tectonic plates, almost 20-25 percent of the total motion, shows up several hundred miles to the east, in the Walker Lane Belt, says Ian Pierce, a postdoctoral researcher at Oxford University who studies active faults. The Walker Lane Belt runs roughly parallel to the California-Nevada border, east of the Sierra Nevada. Like the notorious San Andreas, Walker Lane is a right-lateral fault zone, meaning whichever side you are on, the other side moves to the right.

    Spanning 500 miles (800 kilometers) between near Ridgecrest, Calif., at its southern extent into the northern Sierra Nevada, the Walker Lane Belt comprises many smaller zones of right-lateral faulting that are linked by small left-lateral faults, says Pierce. “It looks like this earthquake was one of those left-lateral faults rupturing,” he says. “As far as the tectonic setting,” he continues, “it’s basically the same as Ridgecrest last year.”

    Similarities to Ridgecrest

    On July 4, 2019, a magnitude-6.4 foreshock rattled Ridgecrest’s residents, but that was just the opening act to the magnitude-7.1 mainshock, which occurred 34 hours later. Pierce compares the Tonopah earthquake with the Ridgecrest foreshock, and points out that aside from their similar magnitudes, “they both occurred on left-lateral faults with small surface ruptures on fairly short—maybe 20-kilometer—fault[s]

    2
    Map of the southern section of the Walker Lane Belt around surrounding regions showing the the past 30 days of earthquake activity. The three stars indicate important quakes—the July 2019 Ridgecrest magnitude-6.4 foreshock, the July 2019 Ridgecrest magnitude-7.1 mainshock, and the Tonopah magnitude-6.5 event of May 15, 2020. Stars are scaled to correspond with magnitude. Credit: Temblor

    However, Pierce says, although Ridgecrest started with a big quake and was followed by an even larger one the next day, “we probably won’t have a magnitude-7.1 tomorrow.”

    Aftershock forecasts

    The U.S. Geological Survey (USGS) issues aftershock forecasts, which can be found here. Over the course of the next week, the chance of an aftershock with magnitude-7.0 or higher is 1 percent, indicating that it’s certainly possible, but with very low probability. On the other hand, the chance of a magnitude-3.0 aftershock or higher is greater than 99 percent. As of this writing, at least 12 aftershocks greater than magnitude-4.0 have been reported, including magnitude-4.9 and magnitude-5.1 shocks that occurred less than an hour after the mainshock.

    “People don’t think of Nevada as being very active, but it really is,” says Kathleen Hodgkinson, a geophysicist at UNAVCO.

    Felt on the other side of the mountains

    As of this writing, more than 21,000 people have reported feeling (or not feeling) the event, according to the USGS “Did you Feel It?” citizen science initiative. People felt the distinctive shaking associated with earthquakes in Las Vegas, about 170 miles (280 kilometers) to the southeast, all the way to the California Bay Area, about 280 miles (450 kilometers) west. Austin Elliot, a research geologist at the USGS Earthquake Science Center in the Bay Area, described waking up to “the seemingly ceaseless thumping of the closet doors” on twitter. He also pointed out that “building height amplified the otherwise maybe imperceptible ground motions,” referencing the fact that the higher up you are, the more likely you are to feel the swaying as seismic waves pass by.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 1:24 pm on March 19, 2020 Permalink | Reply
    Tags: "Earthquake strikes Utah amid COVID-19 pandemic", Luckily preparations made for COVID-19 also prepare people for dealing with an earthquake., temblor, This quake serves as a reminder that Mother Nature doesn’t take a break just because there’s a pandemic., Utah is still in “earthquake country” due to its numerous faults.   

    From temblor: “Earthquake strikes Utah amid COVID-19 pandemic” 

    1

    From temblor

    March 18, 2020
    Tiegan Hobbs, PhD

    As residents prepared for a pandemic, a magnitude-5.7 quake shook Salt Lake City, causing a chemical spill in the nearby mine and closing the airport.

    At 7:09 a.m. local time on March 18, 2020, the ground started shaking in Salt Lake City, Utah. The earthquake had a magnitude of 5.7, releasing 11 times less energy than the smaller of the two 2019 magnitude 6.4 and 7.1 Ridgecrest events in California. Despite being relatively small, the event closed down the Salt Lake City Airport and was felt as far away as Raleigh, N.C.! Within the first three hours, more than 30 aftershocks were recorded, leaving residents of this usually pleasant city feeling uneasy — particularly during the early stages of a viral pandemic.

    This quake serves as a reminder that Mother Nature doesn’t take a break just because there’s a pandemic. Luckily, preparations made for COVID-19 also prepare people for dealing with an earthquake.

    1
    An aerial view of downtown Salt Lake City and the nearby snow-capped Wasatch Mountains. At the edge of the Wasatch Range lies the major and seismically active Wasatch Fault. Today’s earthquake occurred on an unmapped fault to the west. Image credit: Ron Reiring, CC BY 2.0.

    Scientists expect earthquakes here

    Firstly, some comfort: Earthquakes of this size are expected in the Salt Lake City area. Despite being inland, Utah is still in “earthquake country” due to its numerous faults. The University of Utah reports that there have been six earthquakes with magnitude 3.0 or larger since 1962. That year, a magnitude-5.2 earthquake struck less than 3 miles (5 kilometers) from today’s epicenter.

    Overall, the maximum probable earthquake shaking you can expect in your lifetime in Salt Lake City is a level 5 on the Modified Mercalli Intensity (MMI) scale. The March 18th earthquake, however, had a maximum shaking of level 8. The reason this is so much higher is that global models of maximum shaking don’t include the effect of basins. In this region, the Salt Lake Valley Basin is 1000-2000 feet deep (Radkins et al., 1989), which contributes to a stronger shaking here than in the nearby mountains. This has been observed for Seattle (Pratt et al., 2003), Mexico City (Asimaki et al., 2019), and other cities built atop deep basins.

    2
    Temblor map showing the location of the March 18 mainshock and its aftershocks in the first few hours. The earthquakes are on unmapped faults to the west of the West Valley Fault Zone and the Wasatch Fault. Although the quake registered a maximum shaking of MMI 8 (VIII), the PUSH model predicts a maximum probable lifetime shaking of only MMI 5 (V) here. Image credit: Temblor.

    Earthquake preparedness in the time of COVID-19

    Salt Lake Mayor Erin Mendenhall was quick to make a public statement regarding the earthquake and the ongoing novel coronavirus pandemic. She reminded residents that in “some really strange ways,” being prepared for a pandemic means they were already prepared for an earthquake: shelter in place, with pantries stocked with a couple of weeks’ worth of nonperishable foods and well-supplied first aid kits.

    Additionally, being at home tends to reduce injuries and fatalities in earthquakes, caused by damaged large industrial, commercial or government buildings made from unreinforced masonry or concrete.

    That this earthquake occurred during an evolving viral outbreak response, however, draws attention to the difficulty of responding to multiple disasters simultaneously. No casualties are expected from Utah, but an estimated 2.6 million people were exposed to shaking in this earthquake. With a healthcare system that is already stressed by the ongoing COVID-19 pandemic, it’s easy to imagine the devastating impact of a larger earthquake in Utah or any other populated place.

    Double disasters have happened before too. During the 1991 eruption of Mt. Pinatubo in the Philippines, Typhoon Yunya passed over the region, unleashing strong winds and rain on the volcano and the nearby capital city: Luzon. In this case, much like today’s earthquake in pandemic-ready Utah, the second hazard actually lessened the negative impacts of the first. The Guardian reported that some of the particles that were spewed from the second-largest volcanic eruption of the century would have damaged the ozone far more seriously had the typhoon not shifted the plume.

    Although most combinations of disasters are worse than the sum of their parts, the good news is that preparing for a joint occurrence of hazards is done the same way as preparing for a single hazard: keep your emergency kit well-stocked and have a communication plan with your loved ones. And as with any unfolding disaster, listen only to official news sources like local, state and federal emergency management operations to help limit the spread of misinformation. This was essential in Utah, for example, as rumors swirled nearly instantly after the earthquake about imminent large aftershocks.

    Concerned about earthquakes? Check your risk at Temblor.

    Earthquake causes spill at the nearby copper mine

    As reported by Mary Richards from KSLM Local News, the earthquake caused a hazardous material spill at the nearby Kennecott Copper Mining facility. The fire from this hazardous spill produced a large vertical plume of smoke. At this time, it is unknown if there was any other damage to the mining facilities or the nearby tailings ponds, which have previously been identified as potentially seismically susceptible. The Utah National Guard was deployed to help manage the situation, although all mine staff and personnel have been reported safe.

    Earthquake near, but not on, the major Wasatch Fault

    The majority of earthquakes in the Salt Lake City area tend to locate along the north-south-aligned Wasatch Fault Zone. This fault is “the longest continuous, active [extensional] fault (343 km) in the United States,” and tends to rupture in a major earthquake every 395 years (Machette et al., 1991). It defines the eastern edge of the Basin and Range Province, where extension across the western states pulls the crust apart into a series of valleys called “grabens”.

    For further reading and references see the full article.

    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 10:19 am on March 18, 2020 Permalink | Reply
    Tags: "Faults slip slowly in Cascadia", A new study reveals what this means for future large earthquakes in the region., , , , , Just off the Pacific Northwest coast the Juan de Fuca Plate collides with the North American Plate., temblor, The Cascadia Subduction Zone plate interface slips every few hundred years in very large earthquakes with magnitudes approaching or even above 9.0.   

    From temblor: “Faults slip slowly in Cascadia” 

    1

    From temblor

    March 17, 2020
    Noel Bartlow, Ph.D., Assistant Researcher, Berkeley Seismology Laboratory

    The Cascadia Subduction Zone has occasional large earthquakes and frequent slow-slip events. A new study quantifies how these slow-slip events accommodate tectonic plate motion.

    Subduction zones such as the one beneath the U.S. Pacific Northwest and British Columbia are capable of generating very large and destructive earthquakes. But not all of the tectonic motion accommodated in these areas causes earthquakes that can be felt. Episodic tremor and slip, a type of aseismic fault slip or slow slip, accounts for a large amount of fault motion on the deeper extent of the Cascadia Subduction Zone. A new study reveals what this means for future large earthquakes in the region.

    1
    Seattle, Wash., sits on top of the Cascadia Subduction Zone. Credit: CommunistSquared

    A quiet Cascadia comes to life

    Just off the Pacific Northwest coast, the Juan de Fuca Plate collides with the North American Plate. Here, the Juan de Fuca Plate slides beneath North America, forming the Cascadia Subduction Zone. The contact between these two plates, called the plate interface, is stuck due to friction. Slip on the plate interface is necessary to accommodate the collision of the two plates. The Cascadia Subduction Zone plate interface slips every few hundred years in very large earthquakes with magnitudes approaching or even above 9.0. These earthquakes generate dangerous tsunamis similar to the 2011 magnitude-9.0 Tohoku-Oki earthquake and accompanying tsunami in Japan. The last such event in the Cascadia region occurred more than 320 years ago on January 26, 1700.

    3
    Map showing the Cascadia subduction zone, the Gorda and Explorer “plates” are part of the larger Juan de Fuca tectonic plate, but move in slightly different directions and can be considered sub-plates.

    In between large earthquakes, the plate interface is not silent. Instead it chatters to life every few months with episodic tremor and slip events. In these events, the plate interface slips as it would in an earthquake but takes much longer to do so, releasing the same energy as an earthquake with a magnitude of up to 6.8 over a period of a few days to weeks. These events do not produce dangerous shaking, but they do contain information about how the subduction zone is behaving. An episodic tremor and slip event differs from other slow-slip events in that episodic tremor and slip events recur frequently and are also accompanied by numerous tiny earthquakes called tremor, which are too small for humans to feel.

    In a new study published in the journal Geophysical Research Letters, I reveal how much plate motion is accommodated by these events in the Cascadia Subduction Zone.

    Using GPS satellites to observe plate motion

    Knowing where and how much slip occurs during these events helps scientists understand how they may influence the location and timing of a future large earthquake.

    Measuring slip on a plate interface is not as easy as pulling out a yard stick, however.

    The plate interface lies below Earth’s surface, so to find out how much slip occurs during these events, we needed to look at what we can see—the ground beneath our feet. This is where satellites come in.

    In this study, I used satellite GPS observations to determine how much ground motion occurs during each event. I then calculated how much slip had to occur along the plate interface at depth to account for that ground motion. I tallied up ground motion during these events to find the cumulative effect of all episodic tremor and slip events across the Cascadia Subduction Zone over the last 15-25 years, averaged over time. Applying this systematic approach across the region revealed that not all parts of the subduction zone are behaving the same.

    A highly variable system

    GPS observations and other data collected over the past few decades show that the Juan de Fuca and North American plates are moving toward each other at 40 millimeters per year in the northern part of the subduction zone near Seattle, and 31 millimeters per year in the southern part near Cape Mendocino, CA. The rate of motion between the two plates defines the “slip budget”, or the total amount of slip that must be accommodated everywhere on the plate interface. I compare this total to the amount released in episodic tremor and slip to understand its role in the overall accommodation of slip on the plate interface.

    Episodic tremor and slip events accommodate a highly variable amount of slip along the length of the subduction zone. This has implications for how stress is distributed along the plate interface, and thus where future large earthquakes may nucleate.

    In some areas, the slow-slip events account for all of the measured plate convergence. In the very southern part of the subduction zone, slow slip actually releases more slip than the expected convergence rate of the two plates. This might mean that the plates are moving together faster than previous estimates in this region. In other areas of the interface, the slow-slip events accommodate only a fraction of the convergence motion of the two plates—one-fourth or less of the motion in some places. This means that a lot of the motion between the two plates must be released in another way, most likely as steady creep of the plates past one another but potentially also in future earthquakes.

    4
    Motions of GPS sites in the Cascadia region during episodic tremor and slip events, modified from Bartlow (2020). Each arrow represents one GPS station and its motion relative to the subducting plate. Motions are greatly exaggerated.

    Identifying regions at risk

    Previous work on the plate interface in this region revealed the locations where the plate is locked—that is, where friction prevents slip between the two plates (Schmalzle et al., 2014). Large earthquakes occur in these locked sections when the lock is abruptly broken. My results show that slow slip generally occurs in a region offset from the locked section of the plate interface. This means that at present, these events are less likely to trigger large earthquakes than if they were located right at the edge of the locked zone.

    The main region of episodic tremor and slip in Cascadia is in an area with no locking. This means that the full slip budget is accommodated by episodic tremor and slip. In the majority of the subduction zone where episodic tremor and slip takes up less than the full slip budget, the plate interface is creeping along at a slower rate between these events.

    It is possible that over time the episodic tremor and slip events will migrate closer to the locked zone over time. If this were to occur, it may indicate that the next big earthquake is on the horizon. It is also possible that slow-slip events will become larger or more frequent when a large earthquake is imminent. It is therefore important to monitor episodic tremor and slip in Cascadia over time. The method we applied here can be used to detect these changes and therefore remains an important tool in earthquake hazard monitoring.

    5
    A) Time-averaged episodic tremor and slip rate (colors) and contours of density of tremor detections (brown lines) on the Cascadia plate interface (modified from Bartlow, 2020). B) Same as A, but with a comparison to the location of the locked zone (red and yellow colors) from Schmalzle et al. (2014).

    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 4:34 pm on March 4, 2020 Permalink | Reply
    Tags: "Strong earthquakes on Turkey-Iran border trigger scientific cooperation", A pair of conjugate faults—two faults that intersect like an “X” through Earth’s crust —is to blame., , , , , Goharan Fault in Iran, Saray Fault on the Turkish side, temblor   

    From temblor: “Strong earthquakes on Turkey-Iran border trigger scientific cooperation” 

    1

    From temblor

    March 3, 2020
    By Elisabeth Nadin, Ph.D., Associate Professor, University of Alaska Fairbanks, U.S.
    Haluk Eyidoğan, Ph.D., Professor of Seismology, Istanbul Technical University, Turkey
    Ali Moradi, Ph.D., Director of Iranian Seismological Center and Assistant Professor, Institute of Geophysics, University of Tehran, Iran

    *editor’s note: Haluk Eyidoğan and Ali Moradi provided significant insight into this piece, in addition to their attributed material.

    On February 23, 2020, two earthquakes struck the Turkey-Iran border. Scientists from both countries are now working to figure out which faults ruptured during this event.

    Faults don’t recognize international boundaries. When large earthquakes occur in border regions, scientists are often left piecing together data from different sources to figure out what happened. This is critical to assessing further seismic hazard in the area.

    In the early morning hours of February 23, a magnitude 5.8 earthquake rattled the border between Turkey and Iran. That evening, a magnitude 6 quake struck in the same area. Ten days later, geologists in both countries are still trying to figure out exactly which of the numerous faults in this region ruptured.

    1
    A cluster of earthquakes recently struck the Turkey-Iran border, destroying or damaging thousands of buildings. Credit: Temblor.

    A cluster of earthquakes

    The February 23 events were among several notable quakes in the region in recent days. A cluster of earthquakes occurred in northwestern Iran over the past few weeks, including a magnitude-4.7 on 16 February. The magnitude 5.8 caused 10 fatalities in Turkey, more than 100 injuries between the two countries, and thousands of destroyed or damaged buildings. Ten hours later, the magnitude-6 struck within the same cluster.

    Although seismic hazard agencies around the world calculate earthquake magnitude and location within minutes to hours of any large event, it can still be difficult to know exactly which fault ruptured, and what its precise orientation is. This information is important to understanding future earthquake risk in a region because in some cases energy released during one earthquake could increase stress on a neighboring fault, driving it toward failure.

    Science across borders

    Seismologists Haluk Eyidoğan of Turkey and Ali Moradi of Iran are trying to converge on what faults in the region slipped during this series of earthquakes. They suspect that a pair of conjugate faults—two faults that intersect like an “X” through Earth’s crust —is to blame.

    The complex network of faults throughout Turkey and Iran result from the tectonic march of the Arabian plate into the Eurasian plate, resulting in the rise of the Zagros mountains. “Conjugate fault structures are a common feature in the eastern Anatolian tectonic region,” notes Eyidoğan.

    The two scientists believe that on the Iranian side of the border, the Goharan Fault, oriented northwest–southeast, slipped predominantly by right-lateral motion during the 5.8-magnitude quake. Its conjugate—the other arm of the X—the northeast–southwest-oriented Ravian Fault, slipped by left-lateral motion during the magnitude-6 quake.

    As these faults don’t stop just because there is a national border, it is important to know how their traces continue into Turkey. Differing fault naming and measurement conventions can obscure the continuity of faults from one country to another and make rapid post-event analysis challenging. “As far as I understand, the continuation of the Ravian fault is called the Başkale Fault on the Turkish side,” says Eyidoğan, a professor at Istanbul Technical University. “Can we propose that the Goharan Fault in Iran is the continuation of the Saray Fault on the Turkish side?” he suggests.

    A region at risk of damaging earthquakes

    Earthquakes along strike-slip faults, like those that exist throughout this region, tend to have lower magnitudes than those at convergent margins, but these can still be quite large. The Başkale Fault is capable of producing a magnitude-7 earthquake, for example (Emre et al., 2016). In fact, in 1930 there was a magnitude-7.1 within the same region, on the Salmas Fault parallel to the Goharan–Saray Fault.

    The proximity of the 1930 earthquake and this recent cluster “is important in terms of the energy accumulation in the area, the interaction between the seismogenic sources, and the possible maximum magnitudes for seismic hazard assessments,” notes Farnaz Kamranzad, a seismologist at the University of Tehran. She suggests that this earthquake cluster is similar to an event that occurred in the area in 2012, noting that “moderate earthquakes are quite frequent in the northwest part of Iran.”

    The two recent earthquakes of February 23 were particularly destructive for their size. This is because they occurred at shallow depths—about 10 km for both. The closer to the surface an earthquake nucleates, the less energy dissipates before it reaches the surface, and therefore the more shaking that occurs.

    Knowing the potential for destruction during earthquakes is integral to preparing regions for shaking hazards. Turkey’s most recent earthquake hazard map, published in 2018, indicates that the Başkale fault is capable of generating a magnitude-7 temblor. Despite this warning, this cluster of earthquakes from February, as well as the January earthquake about 500 km to the west on a different fault system, “showed us how unprepared the settlements are for earthquake risks,” says Eyidoğan. He adds, “We are sadly watching how the stone masonry and adobe masonry structures in rural areas are weak, and the so-called reinforced concrete carcass multi-story buildings are demolished in cities.” It is clear that more work is to be done to understand the geology in this region, to better prepare citizens of both countries for future damaging earthquakes.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 1:08 am on January 17, 2020 Permalink | Reply
    Tags: , , , , , https://pubs.geoscienceworld.org/, , San Diego CA, , temblor   

    From temblor: “Past meets present to help future seismic hazard forecasts in San Diego, CA” 

    1

    From temblor

    January 13, 2020
    Alka Tripathy-Lang
    @DrAlkaTrip

    Urbanization obscures a complex fault zone on which downtown San Diego sits, but decades-old geotechnical studies reveal the faults.

    1
    Urbanization in downtown San Diego. Credit: Tony Webster CC-BY-2.0.

    Fault studies often rely on surface expressions of the ground’s movement. In densely populated urban areas, such as San Diego, this evidence is concealed beneath the cityscape. Now, though, a team has used historical reports to trace faults through downtown San Diego in unprecedented detail, establishing a template that other fault-prone cities can follow to illuminate otherwise hidden hazards.

    Urbanization obscures geology

    Downtown San Diego, popular for its beaches and parks, also hosts the active Rose Canyon Fault Zone, a complex hazard that underlies the city from northwest of La Jolla through downtown, before curving into San Diego Bay.

    2
    Rose Canyon Fault. https://www.nbcsandiego.com/

    Like the nearby San Andreas, the Rose Canyon Fault is right-lateral, meaning if you were to stand on one side, the opposite side would appear to move to your right. But it plods along at a rate of 1-2 millimeters per year, unlike its speedy neighbor, which indicates a comparatively lower seismic risk.

    “We haven’t had a major rupture” on the Rose Canyon Fault since people have been living atop it, says Jillian Maloney, a geophysicist at San Diego State University and co-author of the new study. So it’s hard to say what kind of damage would be caused, she says. “But, a magnitude-6.9 [of which this fault is capable] is big.”

    Because of urbanization, though, “there haven’t been any comprehensive geologic investigations” of the faults underlying downtown San Diego, Maloney says. This presents a problem because detailed knowledge of active and inactive fault locations, especially in a complicated area where the fault zone bends, is key for successful seismic hazard assessments, she says. The state and federal government maintain fault maps and databases, but their accuracy at the small scale was unknown.

    3
    Map of the Rose Canyon Fault near San Diego, California, USA. USGS

    Faded pages

    A solution to the lack of detailed fault mapping in downtown San Diego resided in decades of old geotechnical reports. These individual studies the size of a city block or smaller are required by the city for any proposed development near active faults, as mapped by the state. Although the data are public once the reports are filed with the city, the reports had not been integrated into a comprehensive or digital resource, and the city does not maintain a list of such reports.

    4
    This bird’s-eye view of downtown San Diego was drawn by Eli Glover in 1876. Prior to the development of downtown San Diego, the Rose Canyon Fault Zone was expressed on the surface and could be seen laterally offsetting topographic features. Credit: Library of Congress, Geography and Map Division.

    According to Luke Weidman, lead author of this study, which was his master’s project, the first challenge was determining how many reports were even available. Weidman, currently a geologist at geotech firm Geocon, went straight to the source: He asked several of San Diego’s large geotechnical firms for their old publicly available reports in exchange for digitizing them. 


    Weidman scrutinized more than 400 reports he received, dating from 1979 to 2016. Many were uninterpretable because of faded or illegible pages. He assembled the 268 most legible ones into a fault map and database of downtown San Diego. Because reports lacked geographical coordinates, Weidman resorted to property boundaries, building locations, park benches and even trees to locate the reports on a modern map, says Maloney, one of his master’s advisors. Weidman, Maloney and geologist Tom Rockwell also of San Diego State published the findings from their comprehensive interactive digital map last month in Geosphere, along with an analysis of the Rose Canyon Fault Zone in downtown San Diego.

    Below from https://pubs.geoscienceworld.org/

    5
    Map of the Rose Canyon fault zone (RCFZ) through San Diego (SD), California (USA) and across the San Diego Bay pull-apart basin. Black box shows the extent of Figure 3. Grid shows population count per grid cell (∼1 km2) (source: LandScan 2017, Oak Ridge National Laboratory, UT-Battelle, LLC, https://landscan.ornl.gov/). DF—Descanso fault; SBF—Spanish Bight fault; CF—Coronado fault; SSF—Silver Strand fault; LNFZ—La Nacion fault zone.

    6
    Street map of greater downtown San Diego region showing Alquist-Priolo (AP) zones and faults from the U.S. Geological Survey (USGS) fault database (USGS-CGS, 2006). Black box shows the extent of Figures 6, 7, and 8. Background imagery: ESRI, HERE (https://www.here.com/strategic-partners/esri), Garmin, OpenStreetMap contributors, and the GIS community.

    Fault findings

    The team found that downtown San Diego’s active faults—defined in their paper as having ruptured within the past 11,500 years—largely track the state’s active fault maps. However, at the scale of the one-block investigations, they found several faults mapped in the wrong location, and cases of no fault where one was expected. Further, the team uncovered three active faults that were not included in the state or federal maps. At the scale at which geotechnical firms, government, owners and developers need to know active fault locations, the use of this type of data is important, says Diane Murbach, an engineering geologist at Murbach Geotech who was not involved in this study.

    7
    This map of downtown San Diego, Calif., shows fault locations as mapped by the U.S. Geological Survey (USGS), and faults as located by the individual geotechnical reports compiled in the new study. Green, light orange, dark orange and red boxes indicate whether individual geotechnical studies found no hazard (green), active faults (red) or potential fault hazards (dark or light orange). Note that the Rose Canyon Fault Zone as mapped by USGS occasionally intersects green boxes, indicating the fault may be mislocated. Where the fault is active, mismatches exist as well. Note the arrow pointing to the ‘USGS-Geotech fault difference,’ highlighting a significant discrepancy in where the fault was previously mapped, versus where it lies. Credit: Weidman et al., [2019].

    Maloney says they also found other faults that haven’t ruptured in the last 11,500 years. This is important, she says, because “you could have a scenario where an active zone ruptures and propagates to [one] that was previously considered inactive.”

    This research “is the first of its kind that I know of that takes all these different reports from different scales with no set format, and fits them into one [usable] database,” says Nicolas Barth, a geologist at the University of California, Riverside who was not part of this study. Many cities have been built on active faults, obscuring hints of past seismicity, he notes. “This is a nice template for others to use,” he says, “not just in California, but globally.”

    References
    Weidman, L., Maloney, J.M., and Rockwell, T.K. (2019). Geotechnical data synthesis for GIS-based analysis of fault zone geometry and hazard in an urban environment. Geosphere, v.15, 1999-2017. doi:10.1130/GES02098.1

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:34 pm on December 30, 2019 Permalink | Reply
    Tags: "Largest Colombian crustal earthquake in 20 years strikes on Christmas Eve", , , , , , , temblor   

    From temblor: “Largest Colombian crustal earthquake in 20 years strikes on Christmas Eve” 

    1

    From temblor

    December 28, 2019
    Albert Leonardo Aguilar Suarez, Ph.D. candidate, Stanford University
    Ross S. Stein, Ph.D., Temblor, Inc.

    Evacuations in Bogotá and the suspension of transportation systems followed a magnitude-6.2 earthquake, which struck on or near where the North Andean Block grinds against South American Plate. The mainshock was followed just 15 minutes later by a magnitude-5.7 aftershock. Further large aftershocks remain a possibility.

    1
    Bogotá, Colombia, the capital and largest city in the country, was shaken on Christmas Eve by a magnitude-6.2 temblor. Credit: Ian Barbour, CC BY-SA 2.0

    The Christmas Eve gift from the Earth to the people of Colombia was a reminder of Earth’s immense power and destructive potential. A magnitude-6.2 earthquake struck near the town of Mesetas, Meta just after 2 pm local time on December 24. This event was followed 15 minutes later by a magnitude-5.7 aftershock. Both were widely felt in Bogotá, Villavicencio, Cali and other big cities in the country. The shaking caused evacuations in Bogotá and the suspension of transportation systems. Fortunately, no injuries have been reported, but many buildings were damaged near the epicentral region. Damages in Mesetas include cracking of the school, the police station and many houses.

    3
    The magnitude-6.2 and magnitude-5.7 earthquakes struck at the junction of several faults, in a location where strong shaking is expected over a person’s lifetime. In this map, sediment-filled basins would be expected to experience more intense shaking than the highlands. The expected shaking is from Temblor’s PUSH (Probabilistic Uniform Seismic Hazards) model, which is available worldwide.

    4
    Ground motion recorded at the seismic station Tumaco, nearly 600 km away. The magnitude-6.2 shock struck 15 minutes before the magnitude-5.7 shock. Data provided by National Seismological Network at the Colombian Geological Survey (RSNC) and stored on IRIS DMC.

    More to come

    Following a large earthquake, many smaller earthquakes, called aftershocks, occur because of stress changes caused by the mainshock. In the 48 hours following the magnitude-6.2 earthquake, the National Seismological Network of Colombia (RSNC for its initials in Spanish) reported more than 300 aftershocks.

    5
    Aftershocks reported by the National Seismological Network at the Colombian Geological Survey (RSNC).

    In a typical aftershock sequence, earthquakes will become less frequent with time. That is observed here, with the aftershock sequence including several earthquakes greater than magnitude-4.5. These aftershocks will continue for weeks to years, but most will be too small to be felt or cause damage, although we cannot rule out the possibility of a larger event.

    6
    Evolution of aftershocks, with time on the x-axis and magnitude on the y-axis. The size of the circles scale with magnitude to emphasize the y-axis. Notice the decrease in earthquake frequency with time. The vertical dashed line marks the origin time of the magnitude-6.2 event.

    Unsurprising, naturally occurring earthquakes

    The magnitude-6.2 is the largest crustal earthquake that has occurred in Colombia in the last 20 years, but its size and location are not surprising for earthquake scientists. The epicenter is located on the eastern side of the Eastern Cordillera of Colombia, where the Algeciras fault system acts as the boundary between the South American plate and the North Andean Block [Velandia et al., 2005; Veloza et al., 2012]. The Algeciras fault system is as a right-lateral strike slip fault, meaning that whichever side of the fault you’re on, the opposite side moves to the right (see the green arrows on the map below). The Algeciras fault system was also responsible for the largest historical crustal earthquake in Colombia—the 1967 magnitude-7.0 Huila earthquake [Dimaté et al.,2005].

    6
    Large historical and recent earthquakes in the Eastern Cordillera near Bogotá. The green arrows indicate the right-lateral sense of motion of the Algeciras fault system. On the left is the Colombia-Huila seismic sequence (2016-2017-2018). In the middle, highlighted by red boxes are the Christmas earthquakes. The inset shows the tectonic setting of Colombia. CP stands for Caribbean Plate, NP for Nazca Plate, NAB for North Andean Block and SAP for South American Plate.

    The eastern cordillera of Colombia and the faults that run through it are responsible for more than half of the shallow seismicity (i.e. depth < 30 km) reported by RSNC. Small earthquakes happen every day, but for the most part, their shaking is too small to be felt. However, more than two years ago, a magnitude-4.7 earthquake took place ~20 km NE of the epicenter of the magnitude-6.2 Christmas earthquake, which is why the location of the Christmas quake is no surprise at all.

    In recent years, seismic activity surged near the town of Colombia (a town with the same name as the country). Three earthquakes greater than magnitude-5.0 struck the town in October 2016, February 2017 and July 2018, and were felt in major cities. These earthquakes also had a rich sequence of aftershocks, as shown by Aguilar & Prieto [2019]. There, the Altamira and Nazareth faults were responsible for the sequence, which occurred near the intersection of the two. At the time, these three quakes were the largest to occur close to Bogotá, after the 2008 magnitude-5.9 Quetame earthquake.

    This seismicity is naturally occurring, a consequence of the interactions of the geological faults that are building the Eastern Cordillera. They are unrelated to industrial oil and gas activities as many people have falsely claimed on social media. Furthermore, there is no relation between these earthquakes and the so-called ‘activation of the Pacific ring of fire’, which is a headline that goes viral after any notable earthquake near the edge of the Pacific Ocean.

    An opportunity for advancement

    The RSNC recently deployed additional seismometers, including two new stations close to the recent earthquakes—station URMC in Uribe, Meta, installed in March 2018, and station CLBC in Colombia, Huila that started recording on February 2019. These additional seismometers will allow a higher resolution image of seismicity, especially for small quakes that are hidden in the shadow of bigger ones.

    Aguilar & Prieto [2018] and Aguilar et al. [2019] revisited the data recorded by RSNC near Colombia-Huila. Through a systematic search for small earthquakes, they tripled the number of events in the catalog for the years 2016, 2017 and 2018. They also clarified the geometry of these faults via precise relocations. The work in the following weeks and months will be pivotal for gaining further insights into the geometry of the faults and the mechanisms of these earthquakes, as well as the seismic hazard near Bogotá, the largest city in Colombia.

    7
    These are waveforms of the M 6.2 aftershocks, with time pointing upwards. We took the liberty of ‘dressing the tree’ with the red bulbs.

    References
    INGEOMINAS – Servicio Geologico Colombiano (SGC Colombia) (1993): Red Sismologica Nacional de Colombia. International Federation of Digital Seismograph Networks. Dataset/Seismic Network. doi:10.7914/SN/CM

    Dimaté, C., Rivera, L., and Cisternas, A. (2005), Re-visiting large historical earthquakes in the Colombian Eastern Cordillera, Journal of Seismology, 9, 1–22, doi:10.1007/s10950-005-1413-2

    Aguilar, A. and Prieto, G. (2018), Spatial and temporal evolution of source properties in the Colombia-Huila seismic sequence. Seismology of the Americas. Available at: https://www.seismosoc.org/wp-content/uploads/2018/06/poster_AA.pdf

    Aguilar, A. and Prieto, G. (2019), Spatial and temporal evolution of source properties in the Colombia-Huila seismic sequence. Thesis submitted to the National University of Colombia.

    Veloza, G., Styron R., Taylor M., and Morg, A. (2012), Open-source archive of active faults for northwest South America, GSA Today, 22, 4–10. doi:10.1130/GSAT-G156A.1

    Mora-Páez, H., Mencin, D.J., Molnar, P., Diederix, H., Cardona-Piedrahita, L., Peláez-Gaviria, J.-R., and Corchuelo- Cuervo, Y. (2016), GPS velocities and the construction of the Eastern Cordillera of the Colombian Andes, Geophys. Res. Lett., 43, 8407–8416, doi:10.1002/ 2016GL069795.

    Aguilar, A., Prieto, G., Pedraza, P., Pulido, N. and Beroza, G. (2019), The recent seismicity of the Eastern Cordillera of Colombia. American Geophysical Union Fall Meeting.

    Velandia, F., Acosta, J., Terraza, R. and Villegas, H. (2005), The current tectonic motion of the Northern Andes along the Algeciras Fault System in SW Colombia, Tectonophysics, doi:10.1016/j.tecto.2004.12.028.

    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

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: