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  • richardmitnick 10:58 am on May 15, 2019 Permalink | Reply
    Tags: "Two damaging tremors highlight the Philippines’ coast-to-coast earthquake problem", 100% of the Philippines is earthquake country., A tragedy and a success story that followed, , , Shake Alert System, , The first quake was a near-miss of Manilla, The mysterious Philippine Trench, Unlike California   

    From temblor: “Two damaging tremors highlight the Philippines’ coast-to-coast earthquake problem” 

    1

    From temblor

    May 9, 2019
    Chris Rollins, Ph.D.
    Michigan State University

    Unlike California, 100% of the Philippines is earthquake country. Two damaging and deadly earthquakes late last month served as a reminder of this.
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    The 22 and 23 April 2019 Philippines earthquakes against a backdrop of the past month of M≥4.5 shocks, which strike on the many active faults that lace—and formed—the archipelago. At the locations of last month’s quakes, the earthquake magnitude likely in one’s lifetime is over M=7, or about 10-20 times larger than the quakes recently experienced.

    The first quake was a near-miss of Manilla

    On April 22 just after 5 PM local time, a magnitude 6.1 earthquake struck less than 85 km (50 mi) from the Philippine capital of Manila, in the provinces of Zambales and Pampanga on the northern island of Luzon. In footage that went viral around the world (link), the shaking ejected water out of a rooftop swimming pool atop a Manila skyscraper. But back on Earth, the earthquake killed 18 people and caused widespread damage in the epicentral region. Although the epicenter was in Zambales, shaking intensities and damage were worse in neighboring Pampanga, much of which sits on soft sediments that amplify shaking, as reported by the Philippine Institute of Volcanology and Seismology (PHIVOLCS). This is a recurring theme in earthquake hazard: we typically settle near water, often on unconsolidated sediments recently deposited by water flow. This is a good call except when an earthquake strikes.

    2
    Damage in the April 22 M=6.1 earthquake. Photo courtesy of Al Jazeera.

    Luzon is no stranger to earthquakes, as it is surrounded on the west and east by subduction trenches and sliced down the middle by the Philippine Fault, a major left-lateral strike-slip fault (whichever side you are on, the other side has moved to the left), with about the same character and slip rate as the San Andreas Fault. The fault likely partners with the subduction zones to accommodate different components of the regional tectonic strain in a “slip partitioning” system.

    3
    The left-lateral Philippine Fault and right-lateral San Andreas Fault are remarkably similar. They have the same slip rate (~25 mm/yr or 1 in/yr), length, straightness, secondary faults, and each has a history of strong, damaging earthquakes. The Temblor Earthquake Score for San Francisco is 77; in Manila, the Philippine capital, it is 88. Manila is the most densely populated city in the world (12 million residents in the metropolitan area, 22 million in the greater urban area).

    A tragedy and a success story that followed

    In 1990, the Philippine Fault ruptured in a M=7.7 strike-slip earthquake that killed over 1,600 people on Luzon. That earthquake – which provides a possible parallel for future earthquakes on the San Andreas and other strike-slip faults around the world – also appears to have squeezed the magma chamber feeding nearby Mt. Pinatubo and hastened its catastrophic 1991 eruption, the second largest of the 20th century. The volcano reawakened immediately after the M=7.7 shock, and then steadily increased in seismicity and steam eruptions until PHIVOLCS and the USGS jointly announced a likely eruption and called for imminent evacuations. Twelve hours later, Pinatubo erupted, with the warning having saved thousands of lives. This was one of science, collaboration, and diplomacy’s finest hours. It is an ideal we continue to strive for today.

    4
    Many of the famous photos of the 1991 Pinatubo eruption show a textbook mushroom cloud – and are actually from a comparatively minor eruption three days before the cataclysmic VEI 6 finale. This photo, courtesy USGS, is of the finale.

    For its part, the earthquake on April 22 appears to have struck on a strike-slip fault parallel to, but well to the west of, the Philippine Fault. It did strike only 15 km (10 mi) from Pinatubo, so it could conceivably have been influenced by magmatic activity there. The reverse is unlikely, however: PHIVOLCS reported no sign of increased activity at Pinatubo after April 22.

    The mysterious Philippine Trench

    That’s more than enough tectonic unrest for one country (particularly one undergoing rapid development in the early 21st century), but it’s only one piece of the story in the Philippines. On the east side of the country lies the Philippine Trench, along which the Philippine Sea Plate is subducting westward beneath the archipelago. The Philippine Sea Plate’s motion is notoriously difficult to constrain because it is a fully “oceanic plate” with few islands on which to place GPS receivers to track its motion. Further, all of its boundaries are subduction zones, a rarity. But the convergence rate along the Philippine Trench probably exceeds 10 cm/yr (4 in/yr), faster than those in Japan and Alaska, and about three times faster than the Cascadia subduction zone in the Pacific Northwest. This means that the earthquake loading process is very rapid, and so great quakes should be frequent.

    5
    Damage in the April 23 M=6.5 Visayas earthquake, courtesy of CNN.

    The Philippine Trench has produced a handful of M>7 earthquakes in the 20th century, and on April 23, it ruptured in a M=6.4 thrust earthquake beneath the island of Samar. This followed on the heels of the April 22 quake in Luzon by less than 24 hours, and although 48 people were injured, fortunately no one was killed. The April 23 quake occurred at around 45 kilometers (25 miles) depth, which may have resulted in milder shaking than had it struck closer to the surface. (This may also have been true in the 2018 M=7.1 Anchorage, Alaska earthquake, which was a different kind but also occurred at 45 km depth and resulted in no deaths).

    Was the second quake triggered by the first?

    With two M>6 earthquakes striking in less than 24 hours, were they connected in some way? There are two ways this could work: 1) static stress transfer, via the bending of the Earth in the April 22 event, or 2) dynamic triggering, where the waves from the April 22 M=6.1 event bump the April 23 fault towards failure. We can rule out static stress transfer: the two earthquakes occurred 575 km apart (350 miles, the distance from LA to San Francisco), well outside the range of significant stress change from a M=6.1 earthquake. Dynamic triggering is more elusive: the waves from the April 22 event were not felt more than 100 km (60 miles) away, one-sixth of the interevent distance; but the 1992 M=7.3 Landers, California earthquake and the 2002 M=7.9 Denali Fault earthquake did trigger seismicity at much greater distances.

    A ‘smoking gun’ for this case would be if there was an uptick in seismicity or creep on the April 23 fault immediately after the waves from the April 22 event passed. This is difficult to pin down both because the April 23 event was rather deep and because it struck beneath the rugged and sparsely populated center of Samar, where the growing PHIVOLCS seismic network is understandably still sparse. Remember, though, that the April 23 event occurred in a stress regime featuring a subducting plate coming in faster than those in Japan and Alaska. That could generate an earthquake anytime, especially a M=6.4, and history shows that it does.

    The pair is reminiscent of the much larger recent pair in Mexico: The 2017 M=8.2 Tehuantepec shock was followed 12 days later and 600 km away by the M=7.2 Puebla shock, which felled 38 buildings in Mexico City. In previous work, we found that it is unlikely that the two were causally related. The time difference in the Philippines case is much shorter, but quake rates there are much higher, and so the probability of a link seems similarly low. PHIVOLCS came to the same conclusion, and in a timely manner, immediately after the second quake.

    6
    Earthquakes and faults line all sides of the Philippines. Figure from Wong et al. [2014].

    More to come

    These two earthquakes served as a reminder that the tectonic strain and the seismic hazard in the Philippines come from all sides, and fast. The Cotabato Trench to the south produced the Philippines’ deadliest earthquake in 1976, and the Manila Trench to the northwest poses a tsunami hazard to southeast Asia, coastal China and Hong Kong. The country is at risk.

    References

    Bautista, B.C., Bautista, L.P., Barcelona, E.S., Punongbayan, R.S., Laguerta, E.P., Rasdas, A.R., Ambubuyong, G., Amin, E.Q., and Stein, R.S. (1996), Relationship of regional and local structures to Mount Pinatubo activity, in R. S. Punongbayan and C. G. Newhall (Eds.), The 1991-1992 eruption of mount Pinatubo, Philippines, 351-370.

    Hill, D.P., et al. (1993), Seismicity Remotely Triggered by the Magnitude 7.3 Landers, California Earthquake, Science 260(5114), https://science.sciencemag.org/content/260/5114/1617.

    Prejean, S.G., Hill, D.P., Brodsky, E.E., Hough, S.E., Johnston, M.J.S., Malone, S.D., Oppenheimer, D.H., Pitt, A.M., and Richards-Dinger, K. B. (2004), Remotely Triggered Seismicity on the United States West Coast Following the Mw7.9 Denali Fault Earthquake, Bull. Seis. Soc. Am., 94(6B), https://doi.org/10.1785/0120040610.

    Smoczyk, G., Hayes, G., Hamburger, M., Benz, H., Villasenor, A., and Furlong, K. (2010), Seismicity of the Earth 1900-2012: Philippine Sea Plate and Vicinity, USGS Open-File Report 2010-1083, https://doi.org/10.3133/ofr20101083M.

    Wong, I., Dawson, T., and Dober, M. (2014), Evaluating the Seismic Hazards in Metro Manila, Philippines, 14th World Conference on Earthquake Engineering (14WCEE).

    Ye, L., Lay, T., and Kanamori, H. (2012), Intraplate and interplate faulting interactions during the August 31, 2012, Philippine Trench earthquake (Mw 7.6) sequence, Geophys. Res. Lett., 39, L24310, doi:10.1029/2012GL054164.

    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 9:15 am on April 30, 2019 Permalink | Reply
    Tags: "Ten times more earthquakes now detected in Southern California", , , , , Shake Alert System,   

    From temblor: “Ten times more earthquakes now detected in Southern California” 

    1

    From temblor

    April 29, 2019
    Ross S. Stein, Ph.D., Temblor

    What did they do?

    In a study published this month in Science, Zachary Ross and Egill Hauksson (both from Caltech), Daniel Trugman (Los Alamos National Laboratory) and Peter Shearer (Scripps Institution of Oceanography) were able to increase the number of recorded southern California earthquakes during 2010-2017 from 180,000 to 1.8 million. They did this by recovering all the quakes that stuck down to a magnitude of 0.29, whereas in the original catalog, only quakes larger than magnitude 1.7 had been reliably recovered. The relationship between earthquake size and frequency obeys a ‘power-law distribution,’ which means that when you drop down one magnitude unit, you get 10 times more quakes.

    How did they do it?

    They employed a method called ‘template matching’. Template matching takes advantage of the similar waveforms recorded at seismometers for quakes located very close together. Each quake was compared to 248,000 template earthquakes, making this is an enormously computer-intensive process. So, they harnessed an array of 200 NVIDIA graphic processing units. NVIDIA’s are designed for video gaming and for self-driving cars, so this is a special kind of scientific dividend. Then, they more precisely located all the earthquakes using a method called ‘double-difference relocation.’ Both methods have been used for a decade or so, but never on so large a data set. The new catalog is now freely available to all researchers (scedc.caltech.edu), a great gift to seismologists around the world.

    2
    Here is an example of the dazzling detail of the relocated seismicity (colored by depth) in the new catalog, which I annotated. Because most of the seismicity at depth lies to the northeast of the fault at the ground surface, the faults must be inclined 8-9° to the northeast, consistent with earlier studies (Fattaruso et al, 2014).

    Did they discover remote aftershocks of an M=7.2 mainshock up to 300 km (180 mi) away?

    In the panel on the right below, sites where the quake rate is higher in the week after the 2010 M=7.2 El Mayor-Cucapah (Baja California) earthquake are red, while sites where the rate is lower are white. The authors declare these are aftershocks, but in fact, their job is to prove it. This would not be unprecedented, as remote triggering following other large shocks has been widely reported (Hill et al., 1993; Brodsky et al., 2000; Prejean et al., 2004; Velasco et al., 2008; Pollitz et al., 2012). But the difference is that the new study bases its findings exclusively on very small (Magnitude<1.0) quakes.

    3
    The ‘Noise’ plot was kindly provided by the authors; the ‘Signal’ plot comes from their paper, with the blue aftershock zone boundary added here. Sites with no reliable rate change are grey.

    On the left panel above is another ‘week after vs. week before’ comparison provided by Zachry Ross, but not centered in the earthquake, so presumably this is just random quake rate variability. I’ve inscribed a blue line around the apparent (mostly red) aftershock zone, which extends twice as far from the mainshock as had been visible before their new catalog was created. Aftershocks promoted by the permanent stress changes in the earth should extend to about 100-135 km, and so the authors ascribe the more distant shocks to dynamic triggering carried by the seismic waves, which reach 300 km away within about 2 minutes from the time the quake begins; within about an hour, those waves will have encircled the globe and will have dissipated, if not disappeared, in southern California.

    Here, below, is another figure in their paper that I have annotated, showing the quake rate relative to the preceding year collapsed on to a line with distance from the epicenter. The quakes within about 135 km or twice the fault length, are consistent with static stress triggering. But for the next 100 km, the quake rate does not decay, which is not what one would expect if they were caused by the seismic wave propagation, which diminishes in amplitude as it propagates away from the rupture, just as ripples diminish in amplitude and spread out as they expand after one throws a stone into a pond. If there is a decay, it is obscured by noise.

    4
    The aftershocks the authors attribute to remote dynamically triggered events exhibit a rate 2-4 times higher in the week after the mainshock than in the preceding year.

    In the next figure below, I compare the authors’ aftershock plot with their plot of seismicity density for the entire catalog period, 2008-2017. If the red quakes are indeed aftershocks, then they should not be correlated with the event density. That’s because aftershock locations should be most influenced by the epicenter and fault rupture. But here, instead, the aftershocks locate just where the long-term seismic rate is highest. It’s almost as if the location of the mainshock doesn’t matter. How could that be so?

    5
    Annotated versions of the figures in Ross et al. (2019). The seismicity density (the number of quakes in each 2 km x km cell) is on the left, and the elevated quake rate after the 2010 mainshock is on the right.

    Here are two possible explanations for this conundrum:

    • Since the event density plot contains the 2010 aftershocks, the two plots are not independent. An event density plot with the first week, or year, after the M=7.2 shock removed would make them nearly independent. I asked the authors if they could provide it, but they chose not to. Irrespective, the highest aftershock density will be near the (yellow) fault rupture, from the U.S.-Mexico border to the south. But the correlation extends ~200 km northwest of that, so I suspect the correlation will remain regardless.

    • If the correlation between longterm event density and aftershocks is real, it would mean that the places which preferentially respond to dynamic triggering are those with very high local seismicity rates, not those with a particular fault geometry or distance from the epicenter. The amplitude and character of the seismic waves would be less important than the sensitivity of certain fault locations to shaking. This would be new and exciting new.

    So, are the remote aftershocks a discovery or a mirage?

    Here is what the authors, or any researchers, would need to do to prove that these events are aftershocks: At least some aftershocks should be triggered as the seismic waves move past those locations in the first few minutes, and no aftershocks at all can strike until the surface waves arrive. Further, the one attribute that distinguishes aftershocks from all other shocks is that their occurrence rate decreases with time in a very particular way: the quake rate decays with 1/time (e.g., 10 hr after the mainshock, the quake rate is 1/10th of its rate in the first hour, 100 hr after the mainshock, the quake rate is 1/100th of its rate in the first hour, etc.). This is called Omori decay in honor of its discovery in 1894 by the Japanese seismologist, Fusakichi Omori, who also came to San Francisco to study the great 1906 earthquake. If the red quakes do not exhibit Omori decay, they are not aftershocks. Another case of tiny, dynamically triggered earthquakes were falsified by these tests (Felzer and Brodsky, 2006; Richards-Dinger et al., 2010).

    If these really are aftershocks, and if they really are correlated with the background seismicity rate, we are going to learn something new and important about how the Earth works.

    References

    Emily E. Brodsky, Vassilis Karakostas, and Hiroo Kanamori, A New Observation of Dynamically Triggered Regional Seismicity: Earthquakes in Greece Following the August, 1999 Izmit, Turkey Earthquake, Geophys. Res. Let., 27, 2741-2744.

    Laura A. Fattaruso, Michele L. Cooke, and Rebecca J. Dorsey (2014), Sensitivity of uplift patterns to dip of the San Andreas fault in the Coachella Valley, California, Geosphere, 10, 1235–1246, doi:10.1130/GES01050.1

    Karen R. Felzer & E. E. Brodsky (2006), Decay of aftershock density with distance indicates triggering by dynamic stress, Nature, 441, 735–738, doi:10.1038/nature04799

    David P. Hill, P. A. Reasenberg, A. Michael, W. J. Arabaz, G. Beroza, D. Brumbaugh4, J. N. Brune, R. Castro, S. Davis, D. dePolo, W. L. Ellsworth, J. Gomberg, S. Harmsen, L. House, S. M. Jackson, M. J. S. Johnston, L. Jones, R. Keller, S. Malone, L. Munguia, S. Nava, J. C. Pechmann, A. Sanford, R. W. Simpson, R. B. Smith, M. Stark, M. Stickney, A. Vidal, S. Walter, V. Wong, J. Zollweg (1993), Seismicity remotely triggered by the Magnitude 7.3 Landers, California, earthquake, Science, 260, doi: 10.1126/science.260.5114.1617

    Stephanie K. Prejean, Hill, D. P., Brodsky, E. E., Hough, S. E., Johnston, M. J. S., Malone, S. D., Oppenheimer, D. H., Pitt, A. M., and Richards-Dinger, K. B. (2004), Remotely triggered seismicity on the United States west coast following the Mw 7.9 Denali Fault earthquake, Bull. Seism. Soc. Am., 94, S348-S359.

    Keith Richards-Dinger, R.S. Stein, R.S., and S. Toda (2010), Decay of aftershock density with distance does not indicate triggering by dynamic stress, Nature, 467, 583-586, doi:10.1038/nature0940

    Zachary E. Ross, Daniel T. Trugman, Egill Hauksson, and Peter M. Shearer (2019), Searching for hidden earthquakes in southern California, Science 10.1126/science.aaw6888.

    Velasco, Aron A., Hernandez, S., Parsons, T., and Pankow, K. (2008). Global ubiquity of dynamic earthquake triggering, Nature Geoscience, 1, 375-379.

    Fred F. Pollitz, R. S. Stein, V. Sevilgen, and R. Bürgmann (2012). The 11 April 2012 East Indian Ocean earthquake triggered large aftershocks worldwide, Nature, 490, 250-253.

    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 8:14 am on March 28, 2019 Permalink | Reply
    Tags: "Did the Moon trigger Saturday’s M=6.1 earthquake in Colombia?", , , , Shake Alert System,   

    From temblor: “Did the Moon trigger Saturday’s M=6.1 earthquake in Colombia?” 

    1

    From temblor

    March 27, 2019
    Aron Mirwald, M.Sc., Temblor, Inc.

    A magnitude 6.1 earthquake occurred on 23 March 2019 at 2:14 pm in Colombia. A recent scientific paper reports that the tide might be responsible for 16% of the earthquakes in Colombia. But did the Moon trigger this earthquake? Possibly, but there are important limitations.

    1
    Colombia’s hyperactive Cauca Cluster and Bucaramanga Nest

    The M=6.1 quake, which was widely felt in Bogota, Cali, and Medellin, was located in the well-known ‘Cauca cluster’ in Colombia, where M≥3 earthquakes occur frequently (~24 per year). Together with the ‘Bucaramanga nest’ (~550 per year), the two clusters account for over half of all Colombian earthquakes (Geological Service Colombia). Most of the earthquakes in the two clusters strike at depths between 70-180 km (43 -111 mi). How earthquakes can be produced at these great depths is itself an enigma, and a matter of ongoing research (read this and this for an introduction).

    But, as for many geoscience problems, there is more to it: Researchers from the Medellin University have found that earthquakes in Colombia correlate with the tide. They show in their recent publication that the relation between earthquakes and tide is especially strong for earthquakes within the two earthquake clusters (Monaco et. al., 2019).

    2
    Each dot represents an earthquake. The colored dots are corresponding to earthquakes in seismic clusters. The upper two are the Cauca cluster and Bucaramanga nest, where over half of the earthquakes in Colombia occur.

    The Moon and the Sun cause the Earth to deform

    Maybe you have heard that we are slightly lighter when the moon is above us (only one millionth of our weight). But, to be exact, this is also true if the moon is directly below us, at the opposite side. The reason for this is that the gravitational force is not the only force at play. The earth is moved by the moon circling around it, and we experience a centrifugal force because of this (here is a webpage with a great animation of this). The net force is upwards both at the side that faces the moon and at the opposite one.

    4
    Both Moon and Earth move in ellipses due to the force they exert on each other. The white arrows represent the net force, i.e. the sum of the centrifugal force and the gravitational force.
    Image from http://beltoforion.de (interactive animation)

    The moon is not the only one who influences the earth. The sun does it in a similar way, although the force it generates is about half as large. The combined effect of the Sun and the Moon is called ‘tide’. The tide has two effects on the earth. First, it moves large quantities of water, also known as ocean tide. Second, it deforms the solid earth: The tidal forces, that pull on both sides, elongate the planet, making it around 40 cm longer. This generates shear and unclamping stresses in the earth that can promote earthquakes (Heaton, 1975).

    The magnitudes of the stresses generated by the tide are much smaller than stresses due to the movement of the tectonic plates. This means that tides themselves are not responsible for earthquakes. Perhaps, however, if an earthquake is about to trigger, the tide can nudge it to fail. Therefore, we would expect seismicity to be higher when the tidal stresses and the tectonic stresses point in the same direction, and lower when the opposite is true.

    Searching for periodicity: can we prove tidal triggering?

    There are two key tidal cycles: The first one is 27.5 days long, which is the time the moon needs to circle around the earth. The second one is 24 hours long, which is the time the earth takes to turn around its own axis. If an increase in the rate of earthquakes correlates with these periods, then that increase could be tidally triggered. The next step would then be to actually compute the stresses involved.

    Could the tides permit earthquake forecasts?

    Since 1980 seismologists have searched for such a link, with mixed results. Recent studies, which have found a relation, are limited to certain regions or circumstances (Ide et. al., 2016). For example, it was found that the number of earthquakes in the region of the 2011 Tohoku earthquake in Japan was correlated with the tide before the earthquake occurred. After the magnitude 9 earthquake, on the other hand, no correlation was found (Tanaka et. al., 2012). Studies like this speculate that it might be possible to evaluate if a large rupture is about to come in certain areas, but this has yet to be proven.

    The recent event was probably facilitated by the tide

    In their research, Dr. Gloria Moncayo and her colleagues evaluated earthquakes in Colombia between 1993 and 2017. They found that the rate of earthquakes indeed had a periodic component, with a period of 27.5 days. About one-sixth (or 16%) more earthquakes occur when the moon is closest, i.e. at a full moon. This correlation between earthquakes and tides was strongest for the events within the Cauca cluster and the Bucaramanga nest.

    The recent earthquake occurred just three days after the last full moon (20 March). In the figure below, this corresponds to a phase of 34°, and thus in an area where more earthquakes are expected due to the tide. We contacted the authors of the research in order to learn more.

    Dr. Moncayo told us that the position and the timing of the event indicated tidal triggering. Her colleague, Dr. Jorge I. Zuluaga, added that they calculated the tidal stress for this event and found that its direction was such that the earthquake would be facilitated. ‘If I could bet a dollar, I would bet that it was tidally triggered. Regretfully, we cannot falsify this assertion’, he wrote.

    6
    Here, you see the number of earthquakes in relation to the 27.5-day period of the moon. A phase of 0 and 360 degrees corresponds to a full moon, and 180 degrees to a new moon. You can see that only a small fraction of the total number of earthquakes varies with time.
    Image from Moncayo et. al. (2019)

    Putting it into perspective: A tidal nudge, but not an earthquake prediction

    For last Saturday’s event, we know that the tidal stress favored the triggering. Before we jump into hasty conclusions, we should be aware that there are limitations to the result of the study of Dr. Moncayo and her colleagues. An important one is that the seismological network has expanded in the time they evaluated. This could introduce error in the detection of periodicity (Ader and Avouac, 2013). Even if the periodicity that the authors found was true, still most of the earthquakes are independent of the tide. Only a fraction (less than 16%) of the seismicity could be attributed to it. Finally, we need to know the actual tidal stresses and not only the periodicity to make statements of the causality.

    References

    Ader, T. J., & Avouac, J. P. (2013). Detecting periodicities and declustering in earthquake catalogs using the Schuster spectrum, application to Himalayan seismicity. Earth and Planetary Science Letters, 377, 97-105.

    Heaton, T. H. (1975). Tidal triggering of earthquakes. Geophysical Journal International, 43(2), 307-326.

    Ide, S., Yabe, S., & Tanaka, Y. (2016). Earthquake potential revealed by tidal influence on earthquake size–frequency statistics. Nature Geoscience, 9(11), 834.

    Moncayo, G. A., Zuluaga, J. I., & Monsalve, G. (2019). Correlation between tides and seismicity in Northwestern South America: the case of Colombia. Journal of South American Earth Sciences, 89, 227-245.

    Tanaka, S. (2012). Tidal triggering of earthquakes prior to the 2011 Tohoku‐Oki earthquake (Mw 9.1). Geophysical research letters, 39(7).

    https://www2.sgc.gov.co/sismos/sismos/ultimos-sismos.html

    http://beltoforion.de/article.php?a=tides_explained&hl=en&p=tides_applet&s=idPageTop#idPageTop

    http://temblor.net/earthquake-insights/the-riddle-of-the-19-september-2017-mexican-earthquake-8481/

    http://news.mit.edu/2013/study-faults-a-runaway-mechanism-in-intermediate-depth-earthquakes-1223

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 12:44 pm on March 22, 2019 Permalink | Reply
    Tags: "How fluid viscosity affects earthquake intensity", , , Induced seismicity as opposed to natural seismicity where earthquakes occur without human intervention, , Shake Alert System, Subsurface exploration projects such as geothermal power injection wells and mining all involve injecting pressurized fluids into fractures in the rock- Read: fracking   

    From École Polytechnique Fédérale de Lausanne: “How fluid viscosity affects earthquake intensity” 

    EPFL bloc

    From École Polytechnique Fédérale de Lausanne

    3.22.19
    Sarah Perrin

    1
    A young researcher at EPFL has demonstrated that the viscosity of fluids present in faults has a direct effect on the force of earthquakes.

    Fault zones play a key role in shaping the deformation of the Earth’s crust. All of these zones contain fluids, which heavily influence how earthquakes propagate. In an article recently published in Nature Communications, Chiara Cornelio, a PhD student at EPFL’s Laboratory of Experimental Rock Mechanics (LEMR), shows how the viscosity of these fluids directly affects an earthquake’s intensity. After running a series of laboratory tests and simulations, Cornelio developed a physical model to accurately calculate variables such as how much energy an earthquake needs to propagate—and, therefore, its strength—according to the viscosity of subsurface fluids.

    The study formed part of wider research into geothermal energy projects which, like other underground activities, can trigger earthquakes – a process known as induced seismicity, as opposed to natural seismicity, where earthquakes occur without human intervention.

    “Subsurface exploration projects such as geothermal power, injection wells and mining all involve injecting pressurized fluids into fractures in the rock,” explains Cornelio. “Studies like this show how a better understanding of the properties and effects of fluids is vital to preventing or attenuating induced earthquakes. Companies should factor these properties into their thinking, rather than focusing solely on volume and pressure considerations.”

    Like soap

    Cornelio ran 36 experiments, simulating earthquakes of varying intensity, and propagating at different speeds, in granite or marble, with fluids of four different viscosities. Her findings demonstrated a clear correlation between fluid viscosity and earthquake intensity.

    “Imagine these fluids working like soap, reducing the friction between your hands when you wash them, or like the oil you spray on mechanical parts to get them moving again,” explains Marie Violay, an assistant professor and the head of the LEMR. “Moreover, naturally occurring earthquakes produce heat when the two plates rub together. That heat melts the rock, creating a lubricating film that causes the fault to slip even further. Our study also gives us a clearer picture of how that natural process works.”

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    EPFL campus

    EPFL is Europe’s most cosmopolitan technical university. It receives students, professors and staff from over 120 nationalities. With both a Swiss and international calling, it is therefore guided by a constant wish to open up; its missions of teaching, research and partnership impact various circles: universities and engineering schools, developing and emerging countries, secondary schools and gymnasiums, industry and economy, political circles and the general public.

     
  • richardmitnick 1:46 am on March 16, 2019 Permalink | Reply
    Tags: Associate Professor Masaki Ando from the Department of Physics invented a novel kind of gravimeter — the torsion bar antenna (TOBA) — which aims to be the first of such instruments, , , Gravimeters — sensors which measure the strength of local gravity, , Shake Alert System,   

    From University of Tokyo: “Sensing shakes” 

    From University of Tokyo

    March 11, 2019

    A new way to sense earthquakes could help improve early warning systems.

    Earthquake Research Institute

    1
    Contour maps depict changes in gravity gradient immediately before the earthquake hits. The epicenter of the 2011 Tohoku earthquake is marked by (✩). ©2019 Kimura Masaya.

    Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell the difference between life and death. UTokyo researchers demonstrate a new earthquake detection method — their technique exploits subtle telltale gravitational signals traveling ahead of the tremors. Future research could boost early warning systems.

    The shock of the 2011 Tohoku earthquake in eastern Japan still resonates for many. It caused unimaginable devastation, but also generated vast amounts of seismic and other kinds of data. Years later researchers still mine this data to improve models and find novel ways to use it, which could help people in the future. A team of researchers from the University of Tokyo’s Earthquake Research Institute (ERI) found something in this data which could help the field of research and might someday even save lives.

    It all started when ERI Associate Professor Shingo Watada read an interesting physics paper on an unrelated topic by J. Harms from Istituto Nazionale di Fisica Nucleare in Italy. The paper suggests gravimeters — sensors which measure the strength of local gravity — could theoretically detect earthquakes.

    “This got me thinking,” said Watada. “If we have enough seismic and gravitational data from the time and place a big earthquake hit, we could learn to detect earthquakes with gravimeters as well as seismometers. This could be an important tool for future research of seismic phenomena.”

    The idea works like this. Earthquakes occur when a point along the edge of a tectonic plate comprising the earth’s surface makes a sudden movement. This generates seismic waves which radiate from that point at 6-8 kilometers per second. These waves transmit energy through the earth and rapidly alter the density of the subsurface material they pass through. Dense material imparts a slightly greater gravitational attraction than less dense material. As gravity propagates at light speed, sensitive gravimeters can pick up these changes in density ahead of the seismic waves’ arrival.

    2
    A map of Japan showing locations for the epicenter of the 2011 Tohoku earthquake (✩),Kamioka (K), Matsushiro (M) and seismic survey instruments used (△ and ●). ©2019 Kimura Masaya.

    “This is the first time anyone has shown definitive earthquake signals with such a method. Others have investigated the idea, yet not found reliable signals,” elaborated ERI postgraduate Masaya Kimura. “Our approach is unique as we examined a broader range of sensors active during the 2011 earthquake. And we used special processing methods to isolate quiet gravitational signals from the noisy data.”

    Japan is famously very seismically active so it’s no surprise there are extensive networks of seismic instruments on land and at sea in the region. The researchers used a range of seismic data from these and also superconducting gravimeters (SGs) in Kamioka, Gifu Prefecture, and Matsushiro, Nagano Prefecture, in central Japan.

    The signal analysis they performed was extremely reliable scoring what scientists term a 7-sigma accuracy, meaning there is only a one-in-a-trillion chance a result is incorrect. This fact greatly helps to prove the concept and will be useful in calibration of future instruments built specifically to help detect earthquakes. Associate Professor Masaki Ando from the Department of Physics invented a novel kind of gravimeter — the torsion bar antenna (TOBA) — which aims to be the first of such instruments.

    3
    A TOBA with door open to reveal cryogenically cooled sensor platform inside. ©2019 Ando Masaki.

    “SGs and seismometers are not ideal as the sensors within them move together with the instrument, which almost cancels subtle signals from earthquakes,” explained ERI Associate Professor Nobuki Kame. “This is known as an Einstein’s elevator, or the equivalence principle. However, the TOBA will overcome this problem. It senses changes in gravity gradient despite motion. It was originally designed to detect gravitational waves from the big bang, like earthquakes in space, but our purpose is more down-to-earth.”

    The team dreams of a network of TOBA distributed around seismically active regions, an early warning system that could alert people 10 seconds before the first ground shaking waves arrive from an epicenter 100 km away. Many earthquake deaths occur as people are caught off-guard inside buildings that collapse on them. Imagine the difference 10 seconds could make. This will take time but the researchers continually refine models to improve accuracy of the method for eventual use in the field.

    Science paper:
    “Earthquake-induced prompt gravity signals identified in dense array data in Japan,” Masaya Kimura; Nobuki Kame; Shingo Watada; Makiko Ohtani; Akito Araya; Yuichi Imanishi; Masaki Ando; Takashi Kunugi
    Earth, Planets and Space

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Tokyo aims to be a world-class platform for research and education, contributing to human knowledge in partnership with other leading global universities. The University of Tokyo aims to nurture global leaders with a strong sense of public responsibility and a pioneering spirit, possessing both deep specialism and broad knowledge. The University of Tokyo aims to expand the boundaries of human knowledge in partnership with society. Details about how the University is carrying out this mission can be found in the University of Tokyo Charter and the Action Plans.

     
  • richardmitnick 3:56 pm on March 5, 2019 Permalink | Reply
    Tags: , , Earthquake hazards, Geophysicists at Caltech have created a new method for determining earthquake hazards by measuring how fast energy is building up on faults in a specific region and then comparing that to how much is , , , Shake Alert System, The method also allows for an assessment of the likelihood of smaller earthquakes. If one excludes aftershocks the probability that a magnitude 6.0 or greater earthquake will occur in central LA over , They applied the new method to the faults underneath central Los Angeles and found that on the long-term average the strongest earthquake that is likely to occur along those faults is between magnitud, They find that the crust beneath Los Angeles does not seem to be being squeezed from south to north fast enough to make such an earthquake quite as likely, When one tectonic plate pushes against another elastic strain is built up along the boundary between the two plates. The strain increases until one plate either creeps slowly past the other or it jerk   

    From Caltech: “Fast, Simple New Assessment of Earthquake Hazard” 

    Caltech Logo

    From Caltech

    1
    Credit: Juan Vargas, Jean-Philippe Avouac, Chris Rollins / Caltech

    March 04, 2019

    Contact
    Robert Perkins
    (626) 395‑1862
    rperkins@caltech.edu

    Geophysicists at Caltech have created a new method for determining earthquake hazards by measuring how fast energy is building up on faults in a specific region, and then comparing that to how much is being released through fault creep and earthquakes.

    They applied the new method to the faults underneath central Los Angeles, and found that on the long-term average, the strongest earthquake that is likely to occur along those faults is between magnitude 6.8 and 7.1, and that a magnitude 6.8—about 50 percent stronger than the 1994 Northridge earthquake—could occur roughly every 300 years on average.

    That is not to say that a larger earthquake beneath central L.A. is impossible, the researchers say; rather, they find that the crust beneath Los Angeles does not seem to be being squeezed from south to north fast enough to make such an earthquake quite as likely.

    The method also allows for an assessment of the likelihood of smaller earthquakes. If one excludes aftershocks, the probability that a magnitude 6.0 or greater earthquake will occur in central LA over any given 10-year period is about 9 percent, while the chance of a magnitude 6.5 or greater earthquake is about 2 percent.

    A paper describing these findings was published by Geophysical Research Letters on February 27.

    These levels of seismic hazard are somewhat lower but do not differ significantly from what has already been predicted by the Working Group on California Earthquake Probabilities. But that is actually the point, the Caltech scientists say.

    Current state-of-the-art methods for assessing the seismic hazard of an area involve generating a detailed assessment of the kinds of earthquake ruptures that can be expected along each fault, a complicated process that relies on supercomputers to generate a final model. By contrast, the new method—developed by Caltech graduate student Chris Rollins and Jean-Philippe Avouac, Earle C. Anthony Professor of Geology and Mechanical and Civil Engineering—is much simpler, relying on the strain budget and the overall earthquake statistics in a region.

    “We basically ask, ‘Given that central L.A. is being squeezed from north to south at a few millimeters per year, what can we say about how often earthquakes of various magnitudes might occur in the area, and how large earthquakes might get?'” Rollins says.

    When one tectonic plate pushes against another, elastic strain is built up along the boundary between the two plates. The strain increases until one plate either creeps slowly past the other, or it jerks violently. The violent jerks are felt as earthquakes.

    Fortunately, the gradual bending of the crust between earthquakes can be measured at the surface by studying how the earth’s surface deforms. In a previous study [JGR Solid Earth] (done in collaboration with Caltech research software engineer Walter Landry; Don Argus of the Jet Propulsion Laboratory, which is managed by Caltech for NASA; and Sylvain Barbot of USC), Avouac and Rollins measured ground displacement using permanent global positioning system (GPS) stations that are part of the Plate Boundary Observatory network, supported by the National Science Foundation (NSF) and NASA. The GPS measurements revealed how fast the land beneath L.A. is being bent. From that, the researchers calculated how much strain was being released by creep and how much was being stored as elastic strain available to drive earthquakes.

    This research was supported by a NASA Earth and Space Science Fellowship.

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan


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


    Stem Education Coalition

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

    Caltech campus


    Caltech campus

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

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

    1

    From temblor

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

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

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

    Crushing into Eurasia

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

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

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

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

    The Indian plate is buckling

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

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

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

    Seismic Risk in India

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

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

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

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

    Hope for the best, prepare for the worst

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

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

    References

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

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

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

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


    From UCLA Newsroom

    February 11, 2019

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

    1
    Pierre Prakash/European Union

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

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

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

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

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

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

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

    2
    Lingsen Meng. Penny Jennings/UCLA

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

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

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

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

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

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

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

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

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

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

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


    See the full article here .


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

    Stem Education Coalition

    UC LA Campus

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

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

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

    Earthquake Alert

    1

    Earthquake Alert

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

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

    Get the app in the Google Play store.

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

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 11:52 am on January 24, 2019 Permalink | Reply
    Tags: , , Peru-Chile Trench, , Shake Alert System, Strong shaking from central coastal Chile earthquake, , What does it reveal about the next megathrust shock?   

    From temblor: “Strong shaking from central coastal Chile earthquake: What does it reveal about the next megathrust shock?” 

    1

    From temblor

    January 20, 2019
    Jason Patton

    Jason R. Patton, Ph.D.; Jean Baptiste Ammirati, Ph.D., University of Chile National Seismological Center; Ross Stein, Ph.D.; Volkan Sevilgen, M.Sc.

    “It is clear to many of us that the Coquimbo region has an unusual, increasing seismicity that may be preparing the area for a very large earthquake near the end of the present century.”

    Raul Madariaga, Ecole Normale Superieure (Paris) and Universidad de Chile (Santiago)

    An earthquake located just beneath the subduction zone of the Peru-Chile Trench strongly shook Coquimbo and La Serena, and was felt up to 400 km away in Santiago. This quake struck just north of the edge of the M=8.3 Illapel megathrust earthquake, which launched a destructive tsunami in 2015.

    Deep earthquake was felt broadly

    On 20 January 2019 there was an M=6.7 earthquake along the convergent plate boundary on the west coast of Chile, about the same size as the 1994 Northridge quake in southern California or about the size of an earthquake that might hit the San Francisco Bay area In northern CA. The earthquake was quite deep (53 km, or about 33 miles), so was not as damaging as those CA examples. However, it was broadly felt with over 800 USGS Did You Feel It reports at the time we write this article.

    1
    Reports from the USGS Did You Feel It website survey

    For most earthquakes that have a potential to damage people, buildings, or infrastructure, the U.S. Geological Survey prepares an estimate of these types of damage. The PAGER alert is based on the strength of measured and modeled shaking (explained in greater detail here). For this M=6.7 earthquake PAGER assigns a 43% chance that there will be between 10 and 100 fatalities, and a 53% chance that there will be economic losses between $10 and $100 million (USD).

    The largest city near the earthquake, Coquimbo, was hit by a tsunami in 2015 when the adjacent section of the subduction zone ruptured. Below is a photo taken following the 2015 M=8.3 earthquake and tsunami. There are over 300,000 people in Coquimbo and the nearby city of La Serena that likely experienced strong to severe shaking intensity from the M=6.7 event. We were quite surprised that the M=6.7 actually caused as much damage as it has, especially in comparison with the 2015 M=8.3 earthquake, which shook less despite being about 300 times larger.

    The Chilean Navy (SHOA) alert system worked very well yesterday. The SHOA tsunami alert that was withdrawn about 30 min after the earthquake, once it was clear that this was not a subduction event. During that half hour, several thousand people followed instructions and took evacuation routes until told to return. This is a valuable test-run of tsunami warnings, and a credit to Chile.

    Plate motions: locked or slipping?

    The deep marine trench offshore the west coast of Chile is formed by a subduction zone where the Nazca plate is shoved beneath the South America plate. This megathrust fault has a variety of material properties and structures that appear to control where the plates are locked, and so accumulating stress towards the next large earthquake, and where they are slipping ‘aseismically’ past each other, and so with a low likelihood of hosting a great quake.

    Below is a map that shows the location of plate boundaries in the region. The majority of high hazard is associated with the subduction zone fault.

    2
    Seismic hazard for South America (Rhea et al., 2010). The numbers (“80”) indicate the rate at which the Nazca Plate is subducting beneath South America. 80 mm/yr = 3 in/yr.

    Are you in earthquake country? Do you know what the earthquake hazards are where you live, work, or play? Temblor uses a model like the USGS model to forecast the chance that an area may have an earthquake. Learn more about your temblor earthquake score here.

    These locked zones are generally where megathrust earthquakes nucleate. In Chile, below a depth of about 50 km (~30 miles) the plate interface is not locked (Gardi et al., 2017), so megathrust fault earthquakes are generally shallower than this depth. Earthquakes deeper than this generally occur within the Nazca plate slab, called ‘slab’ earthquakes because they lie are within the subducting slab. Often these slab earthquakes are extensional, as was the 20 January 2019 M=6.7 quake.

    3
    Cross section of the subduction zone that forms the Chile Trench.

    Below is an aftershock map prepared by Jean-Baptise Ammirati at the University of Chile and the Chilean National Seismic Network.

    4
    We have added the arrows to suggest that the aftershock alignment hints at a west-dipping tensional fault.

    Earthquake history along the Peru-Chile trench

    Much of the megathrust has slipped during earthquakes in the 20th and 21st centuries. The historic record of earthquakes is shown in the figure below. The vertical lines represent the size and extent of the earthquake. The largest earthquake ever recorded by seismometers was the 1960 M=9.5 Chile shock that caused widespread damage, triggered landslides, and generated a trans-oceanic tsunami that destroyed the built environment and caused casualties in Hawaii, Japan, and the west coast of the USA (e.g. Crescent City).

    In 1922 there was an M=8.5 earthquake in the region of today’s M=6.7 quake (Ruiz and Madariaga, 2018). According to Dr. Raul Madariaga, this 1922 event was a subduction zone earthquake that generated a trans-oceanic tsunami which caused damage in Japan and launched a 9m (30 feet) wave just north or Coquimbo, Chile. There has not been a large earthquake in the area of the 1922 earthquake in almost a century, a time longer than average when compared to the rest of the subduction zone. Nevertheless, there was a 129-year pause between the 1877 and 2005 events to the north.

    Also remarkable is the apparent northward progression of great quakes with time from the 1922 event, to 1946, 1966, 1995, 2007, and 2014, for a distance of 1200 km (11° of latitude).

    5
    Historic earthquake record (on the left) coincides with the map of the megathrust showing an estimate of where the fault is stuck and where it may be freely slipping. The M=6.7 earthquake epicenter is located near the blue star. Slab earthquakes are labeled with a gray star (e.g. 1997 discussed below).

    The nearby 1997 sequence started from the north and advanced to the south during the
    month of July 1997, until it produced the 15 October Punitaqui 1997 earthquake. Seismologists will monitor this event to see if there is any seismic migration, which is rare.

    Geologists use GPS data, remote sensing data, and physical measurements of the Earth to monitor how the Earth deforms during the earthquake cycle. The observations can be “inverted” to estimate where the fault is locked and where it is slipping. The figure above shows an interpretation of where the subduction zone fault is locked, and where it may be slipping. Note how the M=6.7 earthquake struck in an area where the megathrust may be freely slipping.

    What does it mean?

    The historic record of earthquakes along the subduction zone makes clear that the absence of megathrust earthquakes for almost a century at the location of the M=6.7 event is unusually long. While it is possible that the Coquimbo portion of the megathrust is not fully locked, it would be prudent for those living along the coast of Chile would to practice their earthquake drills and prepare their homes and finances to withstand effects from a future large earthquake.

    Stay tuned to the latest news about earthquake, tsunami, landslide, liquefaction, and other natural hazards by signing up for our free email service here.

    Citation: Patton J.R., Ammirati J.B. ,Stein R.S., Sevilgen V., 2019, Strong shaking from central coastal Chile earthquake: What does it reveal about the next megathrust shock?, Temblor, http://doi.org/10.32858/temblor.012

    References

    Beck, S., Barrientos, S., Kausel, E., and Reyes, M., 1998. Source Characteristics of Historic Earthquakes along the Central Chile Subduction Zone in Journal of South American Earth Sciences, v. 11, no. 2, p. 115-129, https://doi.org/10.1016/S0895-9811(98)00005-4

    Gardi, A., A. Lemoine, R. Madariaga, and J. Campos (2006), Modeling of stress transfer in the Coquimbo region of central Chile, J. Geophys. Res., 111, B04307, https://doi.org/10.1029/2004JB003440

    Métois, M., Vigny, C., and Socquet, A., 2016. Interseismic Coupling, Megathrust Earthquakes and Seismic Swarms Along the Chilean Subduction Zone (38°–18°S) in Pure Applied Geophysics, https://doi.org/10.1007/s00024-016-1280-5

    Rhea, S., Hayes, G., Villaseñor, A., Furlong, K.P., Tarr, A.C., and Benz, H.M., 2010. Seismicity of the earth 1900–2007, Nazca Plate and South America: U.S. Geological Survey Open-File Report 2010–1083-E, 1 sheet, scale 1:12,000,000.

    Ruiz, S. and Madariaga, R., 2018. Historical and recent large megathrust earthquakes in Chile in Tectonophysics, v. 733, p. 37-56, https://doi.org/10.1016/j.tecto.2018.01.015

    Learn more about the plate tectonics in this region here.

    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 2:02 pm on January 18, 2019 Permalink | Reply
    Tags: , , Seismic swarm hits Hayward Fault: What does it portend?, Shake Alert System,   

    From temblor: “Seismic swarm hits Hayward Fault: What does it portend?” 

    1

    From temblor

    January 17, 2019
    Jason Patton, Ph.D.

    The San Francisco Bay area is earthquake country. Historic and prehistoric evidence for earthquakes here informs us about the possibility of future shakers. On the Hayward Fault, we have an idea about their upper limit on size, but we don’t know when they will occur. The swarm in progress, with an M=3.4 quake on January 16 and today’s M=3.5 quake near Piedmont and Berkeley, are but one way to peer into an uncertain future. Ultimately, they remind us to be prepared to confront potential disaster.

    Earthquake swarm highlights our earthquake history and our earthquake future

    People in northern California have been in the midst of an earthquake swarm along the Hayward fault. Over 6,000 people reported observations of an M=3.4 quake and so far, over 4,000 have reported to the USGS “Did You Feel It?” website for the M=3.5 morning quake today.

    One may think that these quakes are small, so why do they matter? Why should I care?

    Prior to the 1906 San Francisco earthquake, the 1868 event was called the Great San Francisco Earthquake as the damage was widespread across the entire region. According to the USGS, the Hayward fault has the highest chance of rupture for all faults in the bay area, which is why Temblor’s Earthquake Scores for homes near the fault are among the highest anywhere in the U.S.

    The USGS, California Geological Survey, and other stakeholders like the California Earthquake Authority (earthquake insurance) have teamed up to help people learn about a probable repeat of the 1868 earthquake. Learn more about the “HayWired Scenario” on this website.

    Below is a map that shows how the shaking intensity may be across the region in a scenario M=7 quake, similar to the 1868 event. (Hudnut et al., 2018).

    2
    Shaking severity from an hypothetical earthquake on the Hayward fault.

    Last year there was an M=4.4 earthquake in the Piedmont area, which is pretty close to the swarm of quakes that hit in the past 2 days, although unlike today’s quake, it was not on the main strand of the Hayward Fault. Along the Hayward fault, sometimes there is a series of earthquakes that all have similar magnitudes (a swarm) and sometimes there is an earthquake that is larger than the others (a sequence). According to Dr. Peggy Hellweg, Project Manager for the Berkeley Seismological Laboratory seismic network, “typically what we see on the Hayward fault are sequences” and that there is a sequence about every 2 to 5 years, over the past 20 years. Here is a blog post from the Berkeley Seismo Blog for a quake in 2017.

    Sadly, the USGS cannot respond to press inquiries due to the U.S. Government shutdown. However, we can use the USGS earthquake catalog to learn about the recent history of earthquakes along the Hayward fault (see map below). Within 2 km (1.2 mi) of the fault trace, on average, there are quakes a little less than once a year. Quakes right in the Hayward Fault trace are rarer, they strike about once every 3 years. One sees no obvious migration of these quakes with time, which makes it impossible to identify if the fault is getting ready for a “Big One.”
    3
    Hayward fault earthquake locations since 1985.

    For now, we don’t’ know if this swarm will lead to larger magnitude earthquakes. However, we do know that as time passes, the fault gradually stores more elastic energy and this leads to an increased chance of an earthquake.

    There is lots much we can learn about what happened in past earthquakes so we can prepare for future earthquakes. We recently reviewed what we learned over the past 25 since the 1994 M=6.7 Northridge earthquake here. Note the similar earthquake magnitude for the Hayward and Northridge earthquakes.

    The Hayward Fault is HayWired

    The Hayward Fault is unusual. Part of the Hayward fault is creeping aseismically (moving side by side without earthquakes) and part of the fault is locked (clamped together, storing energy that may be released during an earthquake). As the fault creeps, this places additional stress on the adjacent portions of the fault that are locked. The same is true for small earthquakes like the ongoing swarm, they add stress to the fault. A 100-km-long (60 mi) portion of the San Andreas also creeps, but the rest is locked. What makes the Hayward unique is that it exhibits both behaviors everywhere.

    Scientists have been studying how the fault stores this energy over time (e.g. Shirzaei et al., 2013), using satellite data and physical measurements of plate motion in the region. Shirzaei et al. (2013) found that both creep and these small earthquakes add to the stress on the fault and bring us closer to an earthquake.

    “We estimate that a slip-rate deficit equivalent to Mw 6.3–6.8 has accumulated on the fault, since the last event in 1868.” (Shirzaei and R. Bürgmann, 2013).

    Below is an updated plot provided by Dr. Roland Bürgmann, Professor of Earth and Planetary Science at U.C. Berkeley. This figure shows the fault surface at depth and the color represents how much of the fault is creeping (red = more creep). Drs. Bürgmann and Shirzaei have plotted the earthquake locations from the past decade or so, including from the current swarm.

    4

    Dr. Bürgmann wrote us this morning, “I’d like to point out that it was last year’s M=4.4 quake that made me sign up for earthquake insurance.”

    Ground Shaking, Building Collapse, Landslides, Liquefaction

    This is a short laundry list of potential damage that will probably face northern California residents during and following a future Hayward fault earthquake.

    Conclusions from the USGS HayWired Earthquake Scenario are sobering, however we can take action now to be more resilient in the face of this natural disaster.

    The mainshock will be damaging, but so will be the aftershocks. Building damage may exceed $82 billion (in 2016 dollars). As many as 152,000 households may be displaced, placing as many as 411,000 people on the streets (2000 census data). There may be 800 deaths and over 18,000 injuries. As many as 2,500 people may be trapped in buildings and more than 22,000 people could be stuck in elevators.

    As we mentioned in a report on the Sacramento-San Joaquin River Delta about potential levee failures, there may also be substantial damage to the water supply infrastructure as well. It may take as long as 30 to 210 days to restore water supplies for some of the counties in the bay area. Fires can be expected following a HayWired Scenario event. There may be over 400 fires, causing hundreds of additional deaths and contributing to an additional $30 billion in damages.

    There is a suite of natural hazards information available on the temblor app to help one learn the extent to which people are exposed to these hazards. Below is a map that shows the potential for liquefaction in the region. Learn more about landslides and liquefaction in our report from earlier this year here.

    5
    Liquefaction susceptibility from earthquakes in the SF Bay Area. The red dot is the M=3.5 earthquake felt this morning.

    Do you know where your home or workplace fits in earthquake country? Are you prepared? Check Your Risk in the Temblor app here.

    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

     
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