From temblor: “State finds new active fault strands in Santa Monica, Beverly Hills, and Hollywood”

temblor

July 18, 2017
David Jacobson
Ross Stein

On 13 July, the California Geological Survey released four preliminary Earthquake Fault Zone maps for parts of Los Angeles and Napa counties. The West Los Angeles coverage provides new active fault ‘traces’ (where a fault intersects the Earth’s surface) and ‘zones’ (the areas in which some faulting could occur in an earthquake) for the Santa Monica Fault, the Hollywood Fault, and the Newport-Inglewood Fault. And, yes, the Hollywood Fault is responsible for lifting up one of L.A.’s most sacred landmarks, the “Hollywood” sign atop the Santa Monica Mountain range.

New Fault Zone Mapping

Because fault sections were added, revised, and removed, trillions of dollars of real estate is impacted by these new boundaries. This work is carried out under California law; if property lies within the Alquist-Priolo Earthquake Fault Zones that generally extend 150 meters to each side of a fault, special investigation is required prior to construction. These are preliminary review maps, which will not become official until at least January 11, 2018, but provide a chance to see what new fault research has revealed about the Hollywood, Santa Monica, and Newport-Inglewood Faults, which traverse a wealthy, densely-populated urban corridor.

This map shows the old (current) and new (proposed) faults and ‘Alquist-Priolo’ Fault Zones for west Los Angeles. The preliminary “review maps” released by the California Geological Survey last week reveal a greater area at risk of experiencing earthquake slip. The new, higher resolution fault mapping in red can be compared to the cruder older mapping in blue. The revised Santa Monica Fault would be capable of M=6.7 earthquake. (Data from: California Geological Survey)

The Fault Zones limit residential and commercial development

Alquist-Priolo Zones are defined as regulatory perimeters around active faults. According to Tim Dawson, a senior engineering geologist for the California Geological Survey, these zones are “intended to capture the most hazardous faults that could produce surface displacements of concern to a building.” While a fault rupture can be confined to zones just a few meters (10 ft), because of the uncertainty of the fault location and the possibility of slip on a distributed band of faults, the state makes the zones ~150 meters (500 ft) on either side of the mapped trace of a fault.

If a property is within a Fault Zone, strict guidelines must be followed if new construction or major renovations are planned. Further, development is prohibited directly on active faults found within these zones . All of this is done to ensure public safety. Therefore, new maps like the ones released last week will have significant impacts.

High resolution fault mapping is extremely difficult in densely populated and heavily landscaped areas. Brian Olson, a California Geological Survey engineering geologist used existing maps, radar topographic imagery (LIDAR), old aerial photos, and field observations.

Dr. Rufus Catchings of the U.S. Geological Survey performed a shallow geophysical survey that determined the subsurface geometry of the Santa Monica Fault in the vicinity of the Veterans Administration Hospital (Catchings et al., 2008).

Additionally, Tim Dawson said that, “Professor James Dolan at USC conducted a paleoseismic investigation at the Veterans Administration Hospital on the Santa Monica fault. Other faults studies have been conducted by consultants at schools in the area, as well as other studies done for the proposed LA Metro Purple Line Subway Extension.” In the map above, the old and new fault traces and Alquist-Priolo (A-P) Zones are shown to illustrate the changes. One of these changes is the addition of a 6.3 km2 zone cutting through Beverly Hills, Westwood and Santa Monica.

Which fault sections disappeared, and which were added?

The southernmost 5 km (3 mi) section of the Santa Monica Fault, which formerly sliced through a coveted beach community, has been removed. The fault should have been visible in the Santa Monica bluff face, and probably was not found. This trace also was not expressed in the topography, another clue that it had been mislocated. The central two sections remained, and a new one was added to the north. So, in effect, the fault has migrated closer to the range front of the Santa Monica Mountains.

Prior to the new mapping, there were four discontinuous faults running through Santa Monica. Now, the 5-km-long (3 mi) northern-most section of the Newport-Inglewood Fault, which ruptured in the 1933 M=6.4 Long Beach earthquake, has been removed entirely, and so the Newport-Inglewood and Santa Monica Faults are no longer connected.

What does this mean for earthquake rupture?

But there is now more connectivity and continuity between the Hollywood and Santa Monica Faults, making a through-going rupture more likely, which, if it encompassed the adjacent Raymond Fault could reach Magnitude~7. On the other hand, the possibility of a joint rupture of the northern Newport-Inglewood and Santa Monica Faults is now diminished. The revised 12 km-long fault section of the Santa Monica fault has a high degree of continuity, permitting a M≤6.7 rupture, similar to the 1971 San Fernando or 1994 Northridge earthquake.

Fault traces to green belts

Wouldn’t it be ideal if all these fault traces were turned into green belts? This would be the most appropriate and most valuable use of this land.

Just imagine if all fault traces running through urban areas were turned into green belts like this. (Photo from: Pinterest)

The Right Stuff

These changes in fault traces highlight the importance of continually researching and remapping urban faults, as only with better knowledge can we prepare for the earthquakes which will inevitably happen. Nowhere is this more difficult—or more important—than in dense urban areas like this one.

References
California Geological Survey Press Release dated July 13, 2017: Link

California Geological Survey PDF Map for Preliminary Review: Link

Webpage for the Alquist-Priolo Earthquake Fault Zoning Act: Link

Rong-Gong Lin II and Raoul Rañoa, ‘Earthquake fault maps for Beverly Hills, Santa Monica and other Westside areas could bring development restrictions’ (Los Angeles Times, 13 July 2017): Link

R. D. Catchings, G. Gandhok, M. R. Goldman, D. Okaya, M. J. Rymer, and G. W. Bawden, Near-Surface Location, Geometry, and Velocities of the Santa Monica Fault Zone, Los Angeles, California, Bulletin of the Seismological Society of America, Vol. 98, No. 1, pp. 124–138, February 2008, doi: 10.1785/0120020231.

Olson, Brian, 2017, The Hollywood, Santa Monica, and Newport-Inglewood Faults in the Beverly Hills and Topanga 7½-minute Quadrangles, Los Angeles County, California: California Geological Survey, Fault Evaluation Report #259, 72 pages of text and figures; Plate 1, Compilation of Historical Fault Mapping; Plate 2, Geomorphology of Beverly Hills and Topanga Quadrangles; Plate 3, Recommended Fault Zones for Hollywood Fault, Newport-Inglewood Fault, and Santa Monica Fault.

Acknowledgements
We would like to thank Tim Dawson (California Geological Survey) and Robert H. Sydnor for reviewing this post and for providing valuable insight.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

Earthquake country is beautiful and enticing

Almost everything we love about areas like the San Francisco bay area, the California Southland, Salt Lake City against the Wasatch range, Seattle on Puget Sound, and Portland, is brought to us by the faults. The faults have sculpted the ridges and valleys, and down-dropped the bays, and lifted the mountains which draw us to these western U.S. cities. So, we enjoy the fruits of the faults every day. That means we must learn to live with their occasional spoils: large but infrequent earthquakes. Becoming quake resilient is a small price to pay for living in such a great part of the world, and it is achievable at modest cost.

A personal solution to a global problem

Half of the world’s population lives near active faults, but most of us are unaware of this. You can learn if you are at risk and protect your home, land, and family.

Temblor enables everyone in the continental United States, and many parts of the world, to learn their seismic, landslide, tsunami, and flood hazard. We help you determine the best way to reduce the risk to your home with proactive solutions.

Earthquake maps, soil liquefaction, landslide zones, cost of earthquake damage

In our iPhone and Android and web app, Temblor estimates the likelihood of seismic shaking and home damage. We show how the damage and its costs can be decreased by buying or renting a seismically safe home or retrofitting an older home.

Please share Temblor with your friends and family to help them, and everyone, live well in earthquake country.

Temblor is free and ad-free, and is a 2017 recipient of a highly competitive Small Business Innovation Research (‘SBIR’) grant from the U.S. National Science Foundation.

ShakeAlert: Earthquake Early Warning

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 by 2018.

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, depending on the distance to the epicenter of the earthquake. For very large events like those expected on the San Andreas fault zone or the Cascadia subduction zone the warning time could be much longer because the affected area is much larger. ShakeAlert can give enough time to slow and stop 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 by 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” test 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. This “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

From temblor: “M=4.2 earthquake in Oklahoma widely felt throughout Midwest”

temblor

July 14, 2017
David Jacobson

Shaking from today’s M=4.2 earthquake was widely felt in Oklahoma’s capital of Oklahoma City.

At 8:47 a.m. local time this morning, a M=4.2 earthquake struck central Oklahoma in between the cities of Oklahoma City, Tulsa, and Stillwater. This was followed by five aftershocks, the largest of which was a M=3.8. At 10 a.m. local time, there have been over 1,500 felt reports from the mainshock on the USGS website, from all over the state of Oklahoma, and even in Wichita, Kansas, over 200 km away. So far, there are no reports of damage, which is unlikely given this quake’s moderate magnitude. Additionally, the USGS PAGER system estimates that economic losses should remain extremely minimal, and any fatalities are very unlikely.

This Temblor map shows the location of today’s M=4.2 earthquake in Oklahoma. This quake was widely felt throughout the state, and was also felt in 4 other surrounding states based on USGS felt reports.

According to the USGS, today’s earthquake occurred at a depth of 9.3 km, and was right-lateral strike-slip in nature. This depth is relatively deep for Oklahoma, but still within the range frequently seen. Based on the fault map shown in the Temblor map above, and the strike-slip component of today’s earthquake, it occurred on an unmapped fault in the region. However, the orientation of the structure on which the quake struck is consistent with the regional compression direction outlined in Walsh and Zoback, 2016. Also labeled in the Temblor map is the large northeast-southwest-trending Wilzetta Fault. Based on this fault’s strike (northeast-southwest) and the regional compression, it is not at the preferred orientation to undergo a large rupture. This is good as given its length, it is capable of producing a large magnitude earthquake. Instead, faults with orientations similar to the fault on which today’s quake occurred have a higher likelihood of rupturing.

While when most people think of earthquakes in Oklahoma, they think of induced quakes, based on Walsh and Zoback, 2016, there are no high output disposal wells in the area around today’s earthquake. While it is possible that in the last two years more wells have been put in, this is unlikely since following the 2016 M=5.8 Pawnee earthquake, disposal has been limited around the state. Therefore, today’s quake may have been more natural than many that occur in the state.

Because Temblor does not factor in induced seismicity into the Hazard Rank, we must examine a Petersen et al., 2017 study in which both natural and induced seismicity is factored into the likelihood of damage. The map below shows the chance of damage from an earthquake in 2017 for the entire country. What may be eye-opening is that Oklahoma City has a higher likelihood of experiencing earthquake damage this year than both San Francisco and Los Angeles.

The 2017 seismic hazard forecast map reveals that Oklahoma City actually has a higher threat of experiencing a damaging earthquake than San Francisco and Los Angeles. (Figure from Petersen et. al., 2017)

References
USGS

F. Rall Walsh, III, and Mark D. Zoback, Probabilistic assessment of potential fault slip related to injection-induced earthquakes: Application to north-central Oklahoma, USA, 2016, Geology, doi:10.1130/G38275.1

Mark D. Petersen, Charles S. Mueller, Morgan P. Moschetti, Susan M. Hoover, Allison M. Shumway, Daniel E. McNamara, Robert A. Williams, Andrea L. Llenos, William L. Ellsworth, Andrew J. Michael, Justin L. Rubinstein, Arthur F. McGarr, and Kenneth S. Rukstales, 2017 One-Year Seismic-Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes, Seismological Research Letters, March 2017; 88 (2A), DOI: 10.1785/0220170005

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

Earthquake country is beautiful and enticing

Almost everything we love about areas like the San Francisco bay area, the California Southland, Salt Lake City against the Wasatch range, Seattle on Puget Sound, and Portland, is brought to us by the faults. The faults have sculpted the ridges and valleys, and down-dropped the bays, and lifted the mountains which draw us to these western U.S. cities. So, we enjoy the fruits of the faults every day. That means we must learn to live with their occasional spoils: large but infrequent earthquakes. Becoming quake resilient is a small price to pay for living in such a great part of the world, and it is achievable at modest cost.

A personal solution to a global problem

Half of the world’s population lives near active faults, but most of us are unaware of this. You can learn if you are at risk and protect your home, land, and family.

Temblor enables everyone in the continental United States, and many parts of the world, to learn their seismic, landslide, tsunami, and flood hazard. We help you determine the best way to reduce the risk to your home with proactive solutions.

Earthquake maps, soil liquefaction, landslide zones, cost of earthquake damage

In our iPhone and Android and web app, Temblor estimates the likelihood of seismic shaking and home damage. We show how the damage and its costs can be decreased by buying or renting a seismically safe home or retrofitting an older home.

Please share Temblor with your friends and family to help them, and everyone, live well in earthquake country.

Temblor is free and ad-free, and is a 2017 recipient of a highly competitive Small Business Innovation Research (‘SBIR’) grant from the U.S. National Science Foundation.

ShakeAlert: Earthquake Early Warning

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 by 2018.

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, depending on the distance to the epicenter of the earthquake. For very large events like those expected on the San Andreas fault zone or the Cascadia subduction zone the warning time could be much longer because the affected area is much larger. ShakeAlert can give enough time to slow and stop 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 by 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” test 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. This “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

From temblor: “M=6.4 earthquake strikes off the coast of Papua New Guinea”

temblor

July 13, 2017
David Jacobson

Today’s M=6.4 earthquake in Papua New Guinea struck near the island of New Ireland, in the eastern part of the country. (Photo from: Simon’s Jam Jar)

At 3:36 a.m. local time, a M=6.4 earthquake struck Papua New Guinea just off the island of New Ireland. The eastern part of the country is sparsely populated meaning people were only exposed to light and lesser degrees of shaking. Because of this damage and fatalities are unlikely, and so far no reports of them have come in. Another reason why strong shaking was not felt is because the earthquake occurred offshore and at a depth of 47 km, according to the USGS (The European-Mediterranean Seismological Centre assigned it a depth of 40 km). Based on the USGS focal mechanism, this earthquake was thrust in nature. While compressional earthquakes are common in this region, given the proximity to the New Britain Trench, the strike of today’s earthquake makes it hard to reconcile.

This Temblor map shows the location of today’s earthquake in Papua New Guinea. While this earthquake was compressional in nature, based on the quake’s strike, it was likely not associated with subduction at the New Britain Trench.

In the region around today’s earthquake, much of the seismicity is dominated by the subduction of the Australian Plate. North of the New Britain Trench, the Pacific Plate has been broken up into numerous microplates, all of which are being pushed in various directions. In the USGS map below, relative plate motions are shown, illustrating the complex dynamics of the region. Because of these plate motions, strike-slip and extensional earthquakes are also common. Nonetheless, large subduction zone earthquakes, including a M=7.9 in December 2016 are the events which cause the most damage and fatalities.

This map from the USGS shows historical seismicity and relative plate motions in the region around today’s M=6.4 earthquake (yellow star). What this map illustrates is that rapid deformation and high rates of seismicity is due to relative motion exceeding 100 mm/yr. In this map, one can see that the majority of quakes are associated with subduction at the New Britain Trench. (Map from USGS)

Based on the Global Earthquake Activity Rate (GEAR) model, which is available in Temblor, today’s earthquake should not be considered surprising. This model uses global strain rates and seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. From this model, which is in the figure below, one can see that a M=7.75+ earthquake is likely in your lifetime in this area. Such a large magnitude is likely because the area is undergoing rapid deformation due to plate motions of upwards of 100 mm/yr. Should there be any large aftershocks (so far there is only one M=4.8 in our catalog) we will update this post.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for the region around Papua New Guinea. This model uses global strain rates and seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. From this model, one can see that today’s M=6.4 earthquake should not be considered surprising as a M=7.75+ quake is possible.

References [No links provided.]
USGS
European-Mediterranean Seismological Centre

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

Earthquake country is beautiful and enticing

Almost everything we love about areas like the San Francisco bay area, the California Southland, Salt Lake City against the Wasatch range, Seattle on Puget Sound, and Portland, is brought to us by the faults. The faults have sculpted the ridges and valleys, and down-dropped the bays, and lifted the mountains which draw us to these western U.S. cities. So, we enjoy the fruits of the faults every day. That means we must learn to live with their occasional spoils: large but infrequent earthquakes. Becoming quake resilient is a small price to pay for living in such a great part of the world, and it is achievable at modest cost.

A personal solution to a global problem

Half of the world’s population lives near active faults, but most of us are unaware of this. You can learn if you are at risk and protect your home, land, and family.

Temblor enables everyone in the continental United States, and many parts of the world, to learn their seismic, landslide, tsunami, and flood hazard. We help you determine the best way to reduce the risk to your home with proactive solutions.

Earthquake maps, soil liquefaction, landslide zones, cost of earthquake damage

In our iPhone and Android and web app, Temblor estimates the likelihood of seismic shaking and home damage. We show how the damage and its costs can be decreased by buying or renting a seismically safe home or retrofitting an older home.

Please share Temblor with your friends and family to help them, and everyone, live well in earthquake country.

Temblor is free and ad-free, and is a 2017 recipient of a highly competitive Small Business Innovation Research (‘SBIR’) grant from the U.S. National Science Foundation.

ShakeAlert: Earthquake Early Warning

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 by 2018.

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, depending on the distance to the epicenter of the earthquake. For very large events like those expected on the San Andreas fault zone or the Cascadia subduction zone the warning time could be much longer because the affected area is much larger. ShakeAlert can give enough time to slow and stop 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 by 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” test 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. This “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

From temblor: “A M=7 aftershock is 300 times more likely in the week after a M=7 mainshock in new study”

temblor

July 11, 2017
David Jacobson
Ross Stein

In a new study which will be published tomorrow, the effects of aftershocks in the week following a M=7.0 earthquake are shown to elevate the potential for a second M=7.0 by up to 300 times. This photo shows the San Andreas Fault, which takes center stage in this expansion on the already existing California earthquake hazard model.

Tomorrow, a new study on the California earthquake hazard model will be published, which shows, through computer simulations, that in the week following a M=7.0 earthquake, the likelihood of another M=7.0 quake is up to 300 times greater than the week beforehand. This dramatic jump in likelihood is due to the inclusion of the short-term probabilities associated with aftershock sequences, a factor never before used in statewide comprehensive model like this one.

The California earthquake hazard model, the Uniform California Earthquake Rupture Forecast Version 3 (UCERF3), was first published in 2015, and quantifies the hazard posed by tectonic forces unleashed on faults. The 2015 model was the first to include the possibility that an earthquake on one fault could jump to another fault in a matter of seconds, thereby creating multi-fault ruptures. In doing so, over 250,000 rupture scenarios were created for the state of California, vastly more than in the previous model. The reality of such falling-domino or ‘cascading’ ruptures was demonstrated spectacularly in the 2002 M=7.9 Denali, Alaska, and the 2016 M=7.8 Kaikoura, New Zealand earthquakes.

It the study released tomorrow, dubiously dubbed UCERF3-ETAS (ETAS refers to ‘epidemic-type aftershock sequence’ a concept borrowed from medical research and successfully applied to earthquakes by Yoshihito Ogata of Japan) takes it a step further by attempting to capture the role of aftershocks of all sizes following a mainshock. In a nutshell, for short times after a mainshocks, aftershocks matter.

These figures shows the simulated potential M=2.5+ aftershocks in the week after both a M=7.0 Southern San Andreas earthquake, and a M=7.1 quake on the Hayward Fault running through the East Bay. This figure highlights the potential domino-effect seen by a large earthquake. (Figure from: Field et al., 2017)

Mainshocks, by changing the stress on surrounding faults, trigger aftershocks; if you like, the mainshocks are the ‘parents.’ But these aftershock ‘daughters’ can in turn trigger ‘grand-daughters’ aftershocks of their own, ad infinitum. While most aftershocks of any generation will be smaller than their mainshock, occasionally they will be the same size as their mainshock, and rarely they will be larger. This is contrary to the popular belief that for a M=7 quake, the largest aftershock will be less than M=6. By including this triggering potential and running hundreds of thousands of simulations, what you see as Dr. Field described it, are faults as “conduits of hazard” which appear like blood pumping through veins. It is important to point out that what we are seeing in these figures are not dynamically-triggered remote earthquakes, but rather the potential for one large earthquake to trigger another, and then perhaps another.

The study’s team had to choose an arbitrary time period for consideration. Because aftershocks rapidly decay in time, shorter the period, the greater the gain in triggering likelihood. They chose a week as being societally relevant. Nonetheless, the effects are also given for longer time periods such as a month and a year following a mainshock to illustrate the decayed effects over time. The figure above shows the simulated potential M=2.5+ aftershocks in the week after both a M=7.0 earthquake on the southern San Andreas, and a M=7.1 quake on the Hayward Fault running through the East Bay.

We consider their result an important advance, but there is still room for improvement. The figure below shows the simulated potential M=2.5+ aftershocks in the week after a M=6.1 earthquake along the Parkfield section of the San Andreas, shown in two ways. Such M~6.1 earthquakes have struck this portion of the San Andreas every 20-40 years, the most recent in 2004. The image on the right does not take faults into account, resulting in an idealized halo of simulated aftershocks. But it looks nothing like the actual Parkfield aftershock zones, or any other, which are never halos and often illuminate triggering lobes. Coulomb stress transfer gives this spatial pattern, and and so controls which faults are more likely, and which are less likely, to rupture next. That, in our judgement, is what is missing from this approach. While Dr. Field said in an interview that fault characteristics, such as magnitude-frequency distributions, are incorporated, it is still largely lacks Coulomb stress transfer, and that could come next.

This figure shows how by incorporating the effect an earthquake has on nearby faults, you go from the idealized halo not representative of aftershock sequences (left), to a model which has the appearance of blood being pumped through veins. While this model is a step in the right direction, it still does not incorporate which faults are brought closer to failure, which is required for fault rupture. (Figure from: Field et al., 2017)

The Field et al. study takes a great step forward in quantifying the short-term consequences of a large earthquake. In the week following a large magnitude earthquake the potential for a second large quake can increase 300 times; in the year after the mainshock, the gains are typically a factor of 10 according to Dr. Field.

The message is this: Unfortunately, after a large quake, it may not be over. Instead, there is a chance that the sequence has just begun, and could spawn daughters greater than their parents—as all children aim to be.

References [Sorry, no links provided]

Edward H. Field, Thomas H. Jordan, Morgan T. Page, Kevin R. Milner, Bruce E. Shaw, Timothy E. Dawson, Glenn P. Biasi, Tom Parsons, Jeanne L. Hardebeck, Andrew J. Michael, Ray J. Weldon II, Peter M. Powers, Kaj M. Johnson, Yuehua Zeng, Karen R. Felzer, Nicholas van der Elst, Christopher Madden, Ramon Arrowsmith, Maximilian J. Werner, and Wayne R. Thatcher, A Synoptic View of the Third Uniform California Earthquake Rupture Forecast (UCERF3), Seismological Research Letters Volume 88, Number 5, doi: 10.1785/0220170045

Field, E. H., K. R. Milner, J. L. Hardebeck, M. T. Page, N. van der Elst, T. H. Jordan, A. J. Michael, B. E. Shaw, and M. J. Werner (2017). A spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3-ETAS): Toward an operational earthquake forecast, Bull. Seismol. Soc. Am. 107, doi: 10.1785/0120160173.

Personal correspondence with Dr. Edward (Ned) Field (USGS – Golden, Colorado)

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

From Science Alert: “The Yellowstone Supervolcano Has Just Seen 878 Earthquakes in Two Weeks”

Science Alert

29 JUN 2017
CARLY CASSELLA

Suzi Pratt / shutterstock.com

But don’t freak out just yet.

Yellowstone has had a turbulent June. In just two weeks, the supervolcano that lies underneath the national park was hit with 878 earthquakes. The dense series of earthquakes, called an earthquake swarm, began on June 12. Within one week, the USGS had already recorded 464 earthquakes.

“This is the highest number of earthquakes at Yellowstone within a single week in the past five years,” reported the USGS in a statement [U Utah] released last week.

The majority of the earthquakes were no greater than a magnitude of 1, but the largest reached a magnitude of 4.4, which is the biggest earthquake experienced in Yellowstone since March 2014.

But, thankfully, we don’t need to freak out anytime soon. It is extremely unlikely that these swarms will set off the supervolcano. In fact, the USGS sets the probability of the supervolcano erupting in the coming year at 1 in 730,000, and has kept its volcano alert level at green.

“Swarms in Yellowstone are a common occurrence,” Jamie Farrell, a research professor at the University of Utah, which is part of the Yellowstone Volcano Observatory (YVO), told Newsweek.

“On average, Yellowstone sees around 1,500-2,000 earthquakes per year. Of those, 40 to 50 percent occur as part of earthquake swarms.”

And while the most recent swarm is larger than average, Farrell says there isn’t any evidence that the activity is related to magma moving in the subsurface.

Geologists are constantly monitoring the Yellowstone supervolcano for unusual activity. If the volcano was about to blow, Farrell says they would start seeing increased seismicity, large changes in surface deformation, changes to the hydrothermal system and changes in gas output.

“Typically if we see just one of these things, it doesn’t necessarily mean there is an eruption coming. If we start to see changes in all these things, then a red flag may be raised,” said Farrell.

The Yellowstone supervolcano doesn’t blow very often. In the past two million years, it has only experienced three major eruptions.

But even if it did erupt, Jacob Lowenstern, a scientist in charge of the YVO, says it would be fairly inconsequential.

“If Yellowstone erupts, it’s most likely to be a lava flow, as occurred in nearly all the 80 eruptions since the last ‘supereruption’ 640,000 years ago,” he told Newsweek’s Hannah Osborne.

“A lava flow would be a big deal at Yellowstone, but would have very little regional or continental effect.”

Regardless, Farrell and the rest of the team at the University of Utah assure us they are continuing to monitor the swarm. So there won’t be any nasty surprises sneaking up out of Yellowstone anytime soon.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

From temblor: “M=6.3 earthquake in the Aegean Sea near the Greece-Turkey border causes injuries and damage”

temblor

Vatera, in southern Lesbos experienced strong shaking from today’s M=6.3 earthquake. Numerous reports of damage have come in from this tourist hotspot in the eastern Aegean Sea. (Photo from: villapouloudia.gr)

At 3:28 p.m. local time, a M=6.3 earthquake struck just south of the Greek Island of Lesbos (Lesvos), near the international border with Turkey. So far, there have been 33 aftershocks in close proximity to the mainshock, with the largest being a M=4.9. According to the USGS, severe shaking was felt close to the epicenter, and there are numerous reports of damage on Lesbos, a popular tourist hotspot (see video below). Based on the USGS PAGER system, fatalities are unlikely, while economic losses are estimated to be between $10-100 million.

This Temblor map shows the location of today’s M=6.3 earthquake south of Greek island of Lesbos. The faults on Lesbos’ southern coastline have been added to this map as they are the closest mapped active faults to today’s epicenter. Having said that, today’s quake, which was extensional in nature, likely occurred on a different structure.

The Greek island of Lesbos, is home to approximately 87,000 people, making it the most populated in the Eastern Aegean. The tectonic activity in the area is associated with the broader evolution of the Aegean Sea. Along Lesbos’ southern coastline, and extending offshore are several active faults with components of both left-lateral strike-slip and extensional motion. The main faults, which have been added to the Temblor map above are the Polichnitos-Plomari and Aghios Isidoros-Cape Magiras faults. The Polichnitos-Plomari Fault is primarily extensional, though it also has a strike-slip component. Activity along it is related to theremal activity from the nearby Polichnitos geothermal field. The Aghios Isidoros-Cape Magiras Fault on the other hand is primarily extensional with a small amount of strike-slip motion. While these faults are close to the epicenter of today’s quake, based on the strike of the event, which was almost purely extensional it likely occurred on an additional, unmapped structure within the Aegean Sea.

Due to the quake’s moderate magnitude, and shallow (9 km) depth, shaking was widely felt across the region, including in Athens, the Turkish Cities of Izmir and Istanbul, and Sofia, the capital of Bulgaria. Based on the USGS Shakemap and felt reports from the European-Mediterranean Seismological Centre, over 50 million people were exposed to some degree of shaking. However, damage appears to be isolated to the island of Lesbos, where building facades have come down, and 10 people have been injured.

The video below shows damage sustained on Lesbos in today’s M=6.3 earthquake

In addition to the M=6.3 mainshock, and the 33 aftershocks in close proximity, there also may have been two remote, dynamically-triggered aftershocks, up to 75 km away. One of these, a M=3.3 10 minutes after the mainshock was less than 15 km from Izmir. While it is possible that these quakes are incorrectly located, it is possible that they are remote aftershocks.

Based on the Global Earthquake Activity Rate (GEAR) model, which is available in Temblor, today’s M=6.3 earthquake should not be considered surprising. This model, which uses global strain rates and seismicity since 1977 forecasts what the likely earthquake magnitude is in your lifetime anywhere on earth. From the Temblor map below, one can see that in the location of today’s quake, a M=6.5+ is possible. Therefore, while this earthquake was damaging and caused injuries, a larger quake in the region could happen, resulting in more extreme damage.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for much of the area around the Aegean Sea. From this map, one can see that in the area around today’s M=6.3 earthquake, a M=6.5+ quake is possible. This map also shows a possible remote aftershock and the cities of Athens, Izmir, Istanbul, and Sofia, where shaking from today’s quake was felt.

References
European-Mediterranean Seismological Centre (EMSC)
Chatzipetros, A., Kiratzi, A., Sboras, S., Zouros, N., Pavlides, S., Active Faulting in the nore-eastern Aegean Sea Islands, Tectonophysics 597-598 (2013) 106-122
USGS

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

From temblor: “Deep M=6.9 earthquake in Guatemala possibly preceded by foreshock sequence”

temblor

June 14, 2017
David Jacobson

Guatemala City, approximately 160 km from the epicenter of today’s M=6.9 earthquake experienced moderate shaking. While there are only reports of moderate damage throughout the country, it was very widely felt. (Picture from: imgix.net)

At 1:29 a.m. local time, a M=6.9 earthquake struck western Guatemala near the border with Mexico. Despite the quake’s deep depth (94 km according to the USGS) it was widely felt throughout Central America, including in Guatemala City 160 km away, which is home to 3.3 million people. According to officials in Guatemala, landslides were triggered, blocking highways, and houses were moderately damaged. Fortunately, the region around the epicenter, which, based on the USGS ShakeMap experienced strong shaking, is mountainous and sparsely populated and there is only one known injury. Across the border in Mexico, minor damage was also sustained.

This Temblor map shows the location of today’s M=6.9 earthquake in western Guatemala. Also included in this map is the location of the M=7.5 earthquake in 1976 that killed nearly 23,000 people. The thick red line around this epicenter is the fault rupture area.

This part of Central America is highly seismically active due to a combination of relative plate motions. Off the southern coast, the Cocos Plate is subducting beneath both the North American and Caribbean plates. Additionally, left-lateral strike slip motion is also present in much of eastern and central Guatemala due to the active plate boundary between the North American and Caribbean plates. This means that Guatemala sits on what is known as a triple junction, where three tectonic plates meet.

As a result, this region has experienced large, damaging earthquakes, including a M=7.5 earthquake in 1976 in eastern Guatemala that killed nearly 23,000 people and left more than 75,000 injured (Olcese et al., 1977). That devastating quake occurred at a depth of 5 km, and was on the Motagua Fault, which is a pure left-lateral strike-slip fault. In comparison, today’s quake was almost purely extensional and occurred at the much greater depth of 94 km (according to the USGS). While the location and depth of the earthquake suggests that the rupture occurred near the subducting slab, its extensional nature indicates that it may have been caused by localized steepening of the slab.

While today’s earthquake and the deadly one in 1976 were vastly different in their nature and impact on the region, they highlight an important earthquake characteristic: depth. Even had today’s earthquake been a M=7.5, like the one in 1976, it would not have caused as much damage, because it occurred at a depth 19 times greater. This is because significant energy is lost, resulting in less shaking at the surface. In the side-by-side figures below, USGS ShakeMaps are shown for today’s earthquake, and the one in 1976. From these, one can see that while violent shaking was felt in the 1976 quake, today’s shaking only reached strong levels.

These USGS ShakeMaps show shaking in today’s M=6.9 earthquake (left) and the M=7.5 earthquake in 1976 (right). What is clear in these figures is that shaking levels were significantly higher in the 1976 earthquake. This was due to the fact that the magnitude was greater, and because it occurred at a shallow depth.

Another aspect of this quake which deserves extra attention is that in the nine hours prior to the M=6.9 mainshock, there were five smaller magnitude earthquakes, ranging from M=4.4 to M=5.6, just offshore. Two of these occurred within an hour of the M=6.9, including one just 6 minutes prior. While not necessarily indicative of foreshock events, given they were over 100 km away, the rate at which they occurred is substantially higher than the normal background rate. Therefore, if they were foreshocks, they could indicate that a larger creep event took place at the Middle America Trench. While creep events do not necessarily precede large earthquakes, if this area along the subduction zone were to rupture, a M+7.5 earthquake could result. This would generate severe shaking along the Central American coastline, and could trigger a tsunami. Therefore, these smaller events that preceded the mainshock deserve attention.

Because of the complex tectonic environment on which Honduras, and the rest of Central America sits, large earthquakes should be expected. Using the Global Earthquake Activity Rate (GEAR) model, which is available in Temblor, we can see what the likely earthquake magnitude in your lifetime is anywhere on earth. While today’s quake is deeper than GEAR takes into account, we can still see in the map below that for much of central, western, and southern Guatemala, M=6.75+ earthquakes should be expected. Because of this, residents of the small country should be prepared for, and understand the regional earthquake hazards.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for much of Central America. While today’s earthquake is deeper than is considered by GEAR, it does show that M=6.75+ earthquakes are likely to occur in your lifetime in much of central, western, and southern Guatemala. The GEAR model uses global strain rates and seismicity since 1977 to produce an earthquake forecast.

References
USGS
European-Mediterranean Seismological Centre
Associated Press
A. F. Espinosa, The Guatemalan earthquake of February 4, 1976, a preliminary report, Professional Paper 1002, 1976

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

From temblor: “M=5.3 earthquake shakes Hawaii’s Big Island”

temblor

June 8, 2017
David Jacobson

Today’s M=5.3 earthquake on Hawaii’s Big Island occurred near Hawaii Volcanoes National Park. (Picture from: USGS)

At just past 7 a.m. local time today, a M=5.3 earthquake shook the Big Island of Hawaii. According to the USGS, very strong shaking was felt close to the epicenter, while in the capital city of Hilo 44 km to the north, light shaking was recorded by seismometers. At 11 a.m. this morning, 8 a.m. in Hawaii, over 700 people had reported feeling the quake, which is unlikely to cause damage due to the moderate magnitude and the fact that the epicenter was not close to populated centers. The area in which today’s quake occurred is dominated by active volcanism in Hawaii Volcanoes National Park.

This Temblor map shows the location of today’s M=5.3 earthquake on the Big Island of Hawaii. What is also evident from this figure is that the Big Island is highly seismically active. Some of these quakes are volcanic earthquakes, while others are more traditional quakes.

While most people imagine spectacular lava flows and Kilauea when they think of the Big Island of Hawaii, it is also a seismically active area. The majority of these earthquakes are “volcanic earthquakes,” meaning they are associated with magma moving beneath the surface. These quakes are often too small to be felt, but are picked up by local seismometers.

In addition to these “volcanic earthquakes,” more traditional earthquakes also occur around the Big Island. These are caused as the immense weight of the Big Island causes the entire island to subside. In turn, normal (extensional) faulting results. Based on the location and magnitude of today’s earthquake, one of these normal faults is the likely culprit.

Even though today’s quake was only moderate in size and there have been no reports of damage, the Big Island can and has experienced large magnitude quakes. In both 1975 and 1868, there were M=7.2 and M=7.9 earthquakes in similar locations to today’s earthquake. Both of these events caused damage and triggered local tsunamis up to 15 m high. A tsunami inundation map for Hawaii is shown in the figure below. What this shows is that, it is not just volcanic eruptions that Hawaiians have to be wary of.

This Temblor map shows faults, earthquakes, and a tsunami inundation map for the Big Island of Hawaii.

Based on the Global Earthquake Activity Rate (GEAR) model, today’s M=5.3 earthquake should not be considered surprising. This model uses global strain rates and historical seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. From the Temblor figure below, you can see that nearly the entire Big Island, is susceptible to experiencing a M=5.5+ earthquake in your lifetime.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for the Hawaiian Islands. This model uses global strain rates and seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. What can be seen from this figure is that in the location of today’s M=5.3 earthquake, a M=5.5+ quake is likely. Therefore, today’s shock should not be considered a surprise.

References
Hawaiian Volcano Observatory
USGS
University of Hawaii

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

From temblor: “M=5.6 earthquake strikes Ecuador-Peru border”

temblor

June 5, 2017
David Jacobson

Guayaquil, Ecuador’s largest city experienced weak shaking from today’s M=5.6 earthquake to the south. (Photo from: nextstoplatinamerica.com)

At 4:34 p.m. local time, a M=5.6 earthquake struck Ecuador’s southern border with Peru. While this part of South America is not heavily populated, shaking was felt in the city of Guayaquil, which is home to 3.5 million people. According to the USGS, only light shaking was felt close to the epicenter, while weak shaking was felt in Guayaquil. The USGS also estimates that damage from this quake should remain minimal, and that fatalities are unlikely. Based on reports coming in from South America, two people are reported to have been injured, and minor damage has been noted. Should more information come in, we will update this post.

This Temblor map shows the location of today’s M=5.6 earthquake near the Ecuador-Peru border. Also shown in this figure is the city of Guayaquil, which is Ecuador’s largest city. This city of 3.5 million people experienced weak shaking in the earthquake.

Based on the reported depth from both the USGS (52 km) and the EMSC (60 km), and the thrust focal mechanism, this earthquake likely occurred on the subducting slab where the Nazca Plate slides beneath the South American. By examining the Slab 1.0 model from the USGS’ Gavin Hayes (which is also visible in Temblor as ‘Megathrust Zones’), the subducting slab should be between 50 and 60 km depth in the location of today’s earthquake. Therefore, a minor slip event on the subduction zone is the likely cause of the quake.

While this was a small earthquake, this location, and nearly the entire western margin of South America is prone to large, damaging earthquakes. The Peru-Chile Trench, which marks where the Nazca Plate begins subducting beneath the South American Plate, lies only 20-60 km offshore. It should also be pointed out that even though western South America is at risk of large earthquakes, the behavior of the subducting slab varies greatly. In much of southern Peru, northern Chile, and southern Chile, the slab dips at angles of 25° to 30°. However, in southern Ecuador, and central Chile, the slab dips at 10° or less. In these areas of “flat-slab” subduction, crustal earthquakes within the overlying South American Plate are common. In fact, in 1970, a M=7.2 earthquake just to the west of today’s quake killed at least 80 people and caused liquefaction. This quake occurred at a depth of 25 km, suggesting it was likely an upper crustal event.

This Temblor map shows recent large magnitude subduction zone earthquakes around the location of today’s M=5.6 quake. What is evident is that there have been earthquakes several hundred kilometers to the north and south of today’s event, but none in southern Ecuador. This could mean that the area has built up a significant amount of stress, which could be released in a large subduction zone earthquake, or that the geometry of the subduction zone prevents large events from happening.

Based on the Global Earthquake Activity Rate (GEAR) model, which is available in Temblor, today’s M=5.6 earthquake should not be considered surprising. This model uses global strain rates and seismicity since 1977 to forecast what the likely earthquake magnitude is in your lifetime anywhere on earth. From the Temblor map below, one can see that around the location of today’s event, a M=6.75+ is likely. Therefore, while the moderate event today may not have caused damage or loss of life, this region of South America, like the rest of the continent is prone to experiencing large and damaging earthquakes.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for the area around today’s M=5.6 map. This model uses global strain rates and seismicity since 1977 to forecast the likely earthquake magnitude in your lifetime anywhere on earth. What this figure shows is that in the location of today’s earthquake, a M=6.75+ is likely. Therefore, today’s quake should not be considered surprising.

References
USGS
European Mediterranean Seismological Centre

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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

From Temblor: “M=5.0 Taiwan earthquake preceded by foreshock sequence”

temblor

May 24, 2017
David Jacobson

Southwestern Taiwan was hit by a M=5.0 earthquake today. This quake was preceded by a foreshock sequence that lasted approximately 33 hours. (Photo from: holidayssg.com)

At 9:10 p.m. local time today (24 May), a M=5.0 earthquake struck western Taiwan near the city of Chiayi, which is home to over 250,000 people. This earthquake was preceded by a foreshock sequence of five earthquakes beginning approximately 33 hours earlier. The foreshock sequence began with a M=3.6, and culminated with another M=3.6 five minutes before the M=5.0. Most earthquakes are not preceded by a foreshock sequence, making this quake rare. At this stage, there have been no reports of damage, and according to the Taiwan Central Weather Bureau, moderate shaking was felt in the M=5.0, which can rock buildings, and cause slight damage. So, close to the epicenter, it is possible that minor damage was sustained. Should we hear any reports of damage, we will update this post.

This Temblor map shows the location of the M=5.0 earthquake in Taiwan. In addition to the location from EMSC, the USGS location is also shown to illustrate the discrepancy in the catalogs. One of the earthquakes in the foreshock sequence is also shown.

At this stage, there is a discrepancy between where the USGS and EMSC plot the location of today’s quake. The USGS has it in a stepover between the Chiuchiungkeng and Muchiliao-Liuchia faults, while EMSC has it just to the east of the Chiuchiungkeng Fault. The USGS location has been added to the Temblor map above so that this discrepancy can be seen (For any location outside the United States, Temblor shows EMSC data). The USGS has also produced a focal mechanism for this earthquake, which suggests both strike-slip and extensional components of slip, which is not consistent with the regional geology. Should a Taiwan focal mechanism come out, we will update this post.

Based on the location shown in Temblor, this earthquake was likely associated with the Chiuchiungkeng Fault, a thrust fault within the southwestern foothills of Taiwan. Because of high slip rates associated with this fault, the region is believed to have a high probability of experiencing a large magnitude earthquake. This is verified when we look at the Taiwan Earthquake Model (see below). This model shows the likelihood of strong ground motion in the next 50 years.

This figure shows the Taiwan Earthquake Model with recent earthquakes shown. This colors in the figure represent ground motion values (g) with a 10% likelihood in 50 years. This is the spectral acceleration at a period of 0.3 seconds (3.3 Hz).

In addition to the Taiwan Earthquake Model, we can also consult the Global Earthquake Activity Rate (GEAR) model, to see what the likely earthquake magnitude is for this portion of Taiwan. This model, which uses global strain rates and seismicity since 1977, forecasts what the likely earthquake magnitude in your lifetime is for any location on earth. From the Temblor map below, one can see that a M=7.5 earthquake is likely in your lifetime. Such a quake could be devastating to the country, as a significant portion of the country’s agriculture is grown in southwestern Taiwan, and a large earthquake could damage valuable resources. Should anything change regarding the location or focal mechanism from today’s earthquake, we will update this post.

This Temblor map shows the Global Earthquake Activity Rate (GEAR) model for Taiwan. What can be seen from this figure is that the area around today’s earthquake is susceptible to M=7.5+ quakes. Such an earthquake would be devastating to the area.

References
European-Mediterranean Seismological Centre (EMSC)
USGS
Taiwan Earthquake Model (TEM)
Taiwan Central Weather Bureau

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.

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