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

From temblor

January 13, 2020
Alka Tripathy-Lang
@DrAlkaTrip

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

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

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

Urbanization obscures geology

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

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

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

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

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

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

Faded pages

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

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

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


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

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

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

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

Fault findings

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

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

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

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

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

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

Earthquake Alert

Earthquake Alert

Earthquake Network project

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

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

Get the app in the Google Play store.

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

Meet The Quake-Catcher Network

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

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

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

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

The primary project partners include:

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

The Earthquake Threat

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

Part of the Solution

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

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

System Goal

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

Current Status

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

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

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

Authorities

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

For More Information

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

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

From Discover Magazine: “Why is Puerto Rico Being Struck by Earthquakes?”

From Discover Magazine

January 7, 2020
Erik Klemetti

Multiple large earthquakes have hit Puerto Rico over the past week, all thanks to the geologically-active Caribbean Plate.

The tectonic plates of the world were mapped in 1996, USGS.

Map of recent earthquakes from late December into early January 2020 near Puerto Rico. Credit: USGS.

Since Monday, Puerto Rico has been struck by multiple magnitude 5 and 6 earthquakes. These earthquakes caused significant damage on an island still recovering from the devastation of Hurricane Maria in 2017.

Most people don’t think of the Caribbean as an area rife for geologic activity, but earthquakes and eruptions are common. The major earthquakes in Puerto Rico and Haiti, as well as eruptions on Montserrat are all reminders that complex interactions between tectonic plates lie along the Caribbean Ocean’s margins.

The Caribbean plate lies beneath much of the ocean of the same name (see below). It is bounded in the north and east by the North American plate, to the south by the South American plate and to the west by the Cocos plate. There isn’t much land mass above sea level on the plate beyond the islands that stretch from southern Cuba to the Lesser Antilles, along with parts of Central America like Costa Rica and Panama. A few small platelets have been identified along the margins of the plate as well.

Tectonic plates in the eastern Caribbean with historical earthquakes from 1900-2016 marked. Source: USGS.

The northern edge of the plate is a transform boundary, where the two plates are sliding by each other. This causes stress that leads to earthquakes, much the same as the earthquakes generated along the San Andreas fault in California. This is why we’ve seen large earthquakes in places like Haiti, the Dominican Republic and now Puerto Rico.

Head to the east and you reach the curving arc of islands that form the Lesser Antilles. Many of these islands are homes to potentially active volcanoes, such as Soufrière Hills on Montserrat, Pelée on Martinique, La Soufrière on St. Vincent and more. Other islands are homes to relict volcanoes as well. All these volcanoes have been formed by the North American plate sliding underneath the Caribbean, similar to the Cascade Range in the western United States and Canada.

So, Puerto Rico doesn’t have active volcanoes, but it can experience large earthquakes. One of the most famous in the 1918 San Fermín earthquake that was a magnitude 7.1. Unlike the current temblors, the San Fermín earthquake occurred north of the island under the sea, generating a tsunami. More than 100 people likely died in that event.

The current spate of earthquakes struck near the southern coast of the island. Both of the largest earthquakes — Monday’s M5.8 and Tuesday’s M6.4 — occurred during the early morning hours, when most people are at home. This heightens the risk of injuries and fatalities if homes collapse, but luckily so far the number of deaths is low. However, there has been significant damage to home and infrastructure already made precarious by the devastation of Hurricane Maria. This means longer-term hazards for the people of Puerto Rico.

On top of this, the earthquakes have triggered landslides and rockfalls, increasing the threat to the island’s residents. The shaking also destroyed a picturesque natural bridge on the coast of the island. With dozens of aftershocks so far, it may be quite some time before people feel secure again.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

From EarthSky: “Mexico’s Popocatépetl volcano had a spectacular eruption this week”

From EarthSky

January 9, 2020
Deborah Byrd

El Popo erupts! Well, it erupts often, but Thursday morning’s eruption – which happened at sunrise – was a beauty. El Popo is the nickname for Mexico’s most active volcano, Popocatépetl, near Mexico City. The eruption Thursday caused officials to issue a yellow alert.

The active volcano Popocatépetl – just 43 miles (70 km) southeast of Mexico City, and visible from there when atmospheric conditions permit – erupted Thursday morning, January 9, 2020, spewing ash high into the air and oozing lava. Popocatépetl is affectionately called El Popo by Mexicans. It’s one of Mexico’s most active volcanoes. Officials say no one was hurt as a result of Thursday’s eruption. However, because it’s so near Mexico City, many cameras were trained on it. The sunrise light on the erupting volcano was a sight to see.

Spectacular eruption from one of Mexico’s most active volcanoes, Popocatepetl, Thursday morning. Image via @webcamsdemexico on Twitter.

Officials said the eruption sent up a column of smoke about 2 miles (3 km) into the air, with a moderate ash content.

NOAA’s GOES 16 satellite caught the eruption from space.

NOAA GOES-16

Popocatépetl has low- or medium-level eruptions often, and at times erupts more or less continuously. It has had more than 15 major eruptions since the arrival of the Spanish in 1519, according to Wikipedia.

This morning’s eruption was a beauty, though! In part because of its location so near Mexico City, many cameras are trained on the volcano, and thus the January 9, 2020, eruption has been well documented so far, at this writing mostly on Twitter and YouTube.

A gorgeous shot of Popocatépetl on January 9, 2020, as the sun rose on its eruption. Image via @nuriapiera on Twitter.

By the way, after Thursday’s eruption, official issued a “yellow phase 2.” The translation for this “AmarilloFase2” – explained in the tweet below – is as follows:

“Preventive actions for the alert level #AmarilloFase2: Stay tuned for official information. Prepare important documents. Perform drills and know the location of temporary shelters. Develop a family plan for Civil Protection.”

See the full article here .

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

Stem Education Coalition

Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

From EarthSky: “Magnitude 6.4 earthquake shakes Puerto Rico”

From EarthSky

January 7, 2020
Deborah Byrd

USGS reports that the strong earthquake in Puerto Rico this morning was “widely felt.” Strong to very strong shaking occurred across parts of southern Puerto Rico closest to the event, and moderate shaking occurred across the rest of the island.

The January 7, 2020 6.4-magnitude earthquake in Puerto Rico was centered south of the island. Image via USGS.

On January 7, 2020, a magnitude 6.4 earthquake struck Puerto Rico at 4:24 a.m. local time (08:24:26 UTC). Significant damage is possible. Over the past several weeks, hundreds of small earthquakes have occurred in the Puerto Rico region, beginning in earnest with a magnitude 4.7 earthquake late on December 28 and a magnitude 5.0 event a few hours later.

The magnitude 6.4 earthquake on January 7 was widely felt. According to ShakeMap, strong to very strong shaking occurred across parts of southern Puerto Rico, closest to the event, and moderate shaking occurred across the rest of the island. The NOAA Tsunami Warning System states no tsunami warning or advisory. The USGS summary page on this earthquake includes an aftershock forecast. Aftershocks will continue near the mainshock.

Since the magnitude 4.7 event on December 28, over 400 M 2+ earthquakes have occurred in this region, ten of which were magnitude 4+, including the January 7, 2020, 6.4 event and a January 6, 2020 5.8 quake. The preliminary location of the January 7 6.4 earthquake is within about 7.5 miles (12 km) of the January 6, 2020, magnitude 5.8 earthquake. The proximity of these events to Puerto Rico, and their shallow depth, mean that dozens of these events have been felt on land, though with the exception of the latest two earthquakes, the magnitude 6.4 and the magnitude 5.8, none are likely to have caused significant damage.

The January 6 and 7, 2020, magnitude 5.8 and magnitude 6.4 earthquakes offshore of southwest Puerto Rico occurred as the result of oblique strike slip faulting at shallow depth. At the location of this event, the North America plate converges with the Caribbean plate at a rate of about 20 mm/yr towards the west-southwest. The location and style of faulting for the event is consistent with an intraplate tectonic setting within the upper crust of the Caribbean plate, rather than on the plate boundary between the two plates.

Tectonics in Puerto Rico are dominated by the convergence between the North America and Caribbean plates, with the island being squeezed between the two.

The tectonic plates of the world were mapped in 1996, USGS.

To the north of Puerto Rico, North America subducts beneath the Caribbean plate along the Puerto Rico trench. To the south of the island, and south of today’s earthquake, Caribbean plate upper crust subducts beneath Puerto Rico at the Muertos Trough. The January 6 earthquake, and other recent nearby events, are occurring in the offshore deformation zone bound by the Punta Montalva Fault on land and the Guayanilla Canyon offshore.

See the full article here .

Earthquake Alert

Earthquake Alert

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

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

Get the app in the Google Play store.

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

Meet The Quake-Catcher Network

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

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

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

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

The primary project partners include:

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

The Earthquake Threat

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

Part of the Solution

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

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

System Goal

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

Current Status

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

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

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

Authorities

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

For More Information

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

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

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Please help promote STEM in your local schools.

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Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

From Eos: “Seismic Sensors in Orbit”

From AGU

From Eos

26 December 2019
Timothy I. Melbourne
Diego Melgar
Brendan W. Crowell
Walter M. Szeliga

A continuously telemetered GNSS station located on the Olympic Peninsula of Washington state. Determining the real-time positions of hundreds of stations like this one to accuracies of a few centimeters within a global reference frame opens a new pipeline of analysis tools to monitor and mitigate risk from the seismic and tsunami hazards of the Cascadia Subduction Zone and other fault systems around the globe. Credit: Central Washington University

Imagine it’s 3:00 a.m. along the Pacific Northwest coast—it’s dark outside and most people are asleep indoors rather than alert and going about their day. Suddenly, multiple seismometers along the coast of Washington state are triggered as seismic waves emanate from a seconds-old earthquake. These initial detections are followed rapidly by subsequent triggering of a dozen more instruments spread out both to the north, toward Seattle, and to the south, toward Portland, Ore. Across the region, as the ground begins to shake and windows rattle or objects fall from shelves, many people wake from sleep—while others are slower to sense the potential danger.

Within a few seconds of the seismometers being triggered, computers running long-practiced seismic location and magnitude algorithms estimate the source of the shaking: a magnitude 7.0 earthquake 60 kilometers off the Washington coast at a depth roughly consistent with the Cascadia Subduction Zone (CSZ) interface, along which one tectonic plate scrapes—and occasionally lurches—past another as it descends toward Earth’s interior. The CSZ is a well-studied fault known in the past to have produced both magnitude 9 earthquakes and large tsunamis—the last one in 1700.

Cascadia subduction zone

The initial information provided by seismometers is important in alerting not only scientists but also emergency response personnel and the public to the potentially hazardous seismic activity. But whether these early incoming seismic waves truly represent a magnitude 7 event, whose causative fault ruptured for 15–20 seconds, or whether instead they reflect ongoing fault slip that could last minutes and spread hundreds of kilometers along the fault—representing a magnitude 8 or even 9 earthquake—is very difficult to discern in real time using only local seismometers.

It’s a vital distinction: Although a magnitude 7 quake on the CSZ could certainly cause damage, a magnitude 8 or 9 quake—potentially releasing hundreds of times more energy—would shake a vastly larger region and could produce devastating tsunamis that would inundate long stretches of coastline.

The USGS produced a scenario ShakeMap for a modeled M 9.0 CSZ earthquake for planning purposes. This ShakeMap page provides information about probable shaking levels at different frequencies but is not very useful for site specific estimates nor does it provide much information about potential impacts.

The 1999 24 page Crew Publication, Cascadia Subduction Zone Earthquakes: A Magniude 9 Earthquake Scenario, takes USGS-model ground motions and NOAA tsunami estimates and paints a generalized picture of the likely damages to regional infrastructure. The scenario then identifes challenges that will be faced in responding and recovering from such an event.

In 2007 CREW produced a publication that summarized potential impacts and lessons learned in three tabletop exercises based on the Cascadia earthquake scenario.

Oregon Department of Transportation examined potential damage to bridges during a scenario M8.3 earthquake on the CSZ.

Some communities must evacuate for miles to get out of the potential inundation zone, meaning that every second counts. The ability to characterize earthquake slip and location accurately within a minute or two of a fault rupturing controls how effective early warnings are and could thus mean the difference between life and death for tens of thousands of people living today along the Pacific Northwest coast.

Enter GPS or, more generally, Global Navigation Satellite Systems (GNSS). These systems comprise constellations of Earth-orbiting satellites whose signals are recorded by receivers on the ground and used to determine the receivers’ precise locations through time. GPS is the U.S. system, but several countries, or groups of countries, also operate independent GNSS constellations, including Russia’s GLONASS and the European Union’s Galileo system, among others. Prominently used for navigational purposes, GNSS ground receivers, which in recent years have proliferated by the thousands around the world, now offer useful tools for rapidly and accurately characterizing large earthquakes—supplementing traditional seismic detection networks—as well as many other natural hazards.

An Initial Demonstration

Fig. 1. Examples of GNSS three-dimensional displacement recorded roughly 100 kilometers from the hypocenters of the 2011 magnitude 9.1 Tohoku earthquake in Japan, the 2010 magnitude 8.8 Maule earthquake in Chile, the 2014 magnitude 8.1 Iquique earthquake in Chile, and the 2010 magnitude 7.2 El Mayor-Cucapah earthquake in Mexico. Static displacements accrue over timescales that mimic the evolution of faulting and become discernible as dynamic displacements dissipate. Note the dramatic increase in permanent offsets for the largest events, increasing from about 5 centimeters for El Mayor to over 4 meters for Tohoku. The data are freely available from Ruhl et al. [2019].

Large earthquakes both strongly shake and deform the region around the source fault to extents that GNSS can easily resolve (Figure 1). With the expansion of GNSS networks and continuous telemetry, seismic monitoring based on GNSS measurements has come online over the past few years, using continuously gathered position data from more than a thousand ground stations, a number that is steadily growing. Station positions are computed in a global reference frame at an accuracy of a few centimeters within 1–2 seconds of data acquisition in the field. In the United States, these data are fed into U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA) centers charged with generating and issuing earthquake and tsunami early warnings.

In the scenario above, GNSS-based monitoring would provide an immediate discriminant of earthquake size based on the amount of displacement along the coast of Washington state. Were it a magnitude 7, a dozen or so GNSS stations spread along a roughly 30-kilometer span of the coast might reasonably move a few tens of centimeters within half a minute, whereas a magnitude 8 event—or a magnitude 9 “full rip” along the entire subduction zone, from California to British Columbia—would move hundreds of Cascadia GNSS stations many meters. Ground offset at some might exceed 10 meters, depending on location, but the timing of the offsets along the coast determined with GNSS would track the rupture itself.

The July 2019 strike-slip earthquake sequence in the Eastern California Shear Zone near Ridgecrest in the eastern Mojave Desert provided the first real-world demonstration of the capability of GNSS-based seismic monitoring. The newly developed GNSS monitoring systems included a dozen GNSS stations from the National Science Foundation–supported Network of the Americas (NOTA) located near the fault rupture. Data from these stations indicated that the magnitude 7.1 main shock on 5 July caused coseismic offsets of up to 70 centimeters in under 30 seconds of the initiation of fault slip.

The magnitude 7.1 strike-slip earthquake that occurred in the Mojave Desert near Ridgecrest, Calif., on 5 July 2019 caused the ground surface to rupture. Nearby Global Navigation Satellite Systems (GNSS) stations recorded up to 70 centimeters of offset within 30 seconds of the fault rupture. Credit: U.S. Geological Survey

Further analysis of the data showed that those 30 seconds encompassed the fault rupture duration itself (roughly 10 seconds), another 10 or so seconds as seismic waves and displacements propagated from the fault rupture to nearby GNSS stations, and another few seconds for surface waves and other crustal reverberations to dissipate sufficiently such that coseismic offsets could be cleanly estimated. Latency between the time of data acquisition in the Mojave Desert to their arrival and processing for position at Central Washington University was less than 1.5 seconds, a fraction of the fault rupture time itself. Comparison of the coseismic ground deformation estimated within 30 seconds of the event with that determined several days later, using improved GNSS orbital estimates and a longer data window, shows that the real-time offsets were accurate to within 10% of the postprocessed “true” offsets estimated from daily positions [Melgar et al., 2019]. Much of the discrepancy may be attributable to rapid fault creep in the hours after the earthquake.

A Vital Addition for Hazards Monitoring

This new ability to accurately gauge the position of GNSS receivers within 1–2 seconds from anywhere on Earth has opened a new analysis pipeline that remedies known challenges for our existing arsenal of monitoring tools. Receiver position data streams, coupled to existing geophysical algorithms, allow earthquake magnitudes to be quickly ascertained via simple displacement scaling relationships [Crowell et al., 2013 Geophysical Research Letters]. Detailed information about fault orientation and slip extent and distribution can also be mapped nearly in real time as a fault ruptures [Minson et al., 2014 JGR Solid Earth]. These capabilities may prove particularly useful for earthquake early warning systems: GNSS can be incorporated into these systems to rapidly constrain earthquake magnitude, which determines the areal extent over which warnings are issued for a given shaking intensity [Ruhl et al., 2017 Geophysical Research Letters].

GNSS will never replace seismometers for immediate earthquake identifications because of its vastly lower sensitivity to small ground displacements. But for large earthquakes, GNSS will likely guide the issuance of rapid-fire revised warnings as a rupture continues to grow throughout and beyond the timing of initial, seismometer-based characterization [Murray et al., 2019 Seismological Research Letters].

Deformation measured using GNSS is also useful in characterizing tsunamis produced by earthquakes, 80% of which in the past century were excited either by direct seismic uplift or subsidence of the ocean floor along thrust and extensional faults [Kong et al., 2015 UNESCO UNESDOC Digital Library] or by undersea landslides, such as in the 2018 Palu, Indonesia, earthquake (A. Williamson et al., Coseismic or landslide? The source of the 2018 Palu tsunami, EarthArXiv, https://doi.org/10.31223/osf.io/fnz9j). Rough estimates of tsunami height may be computed nearly simultaneously with fault slip by combining equations describing known hydrodynamic behavior with seafloor uplift determined from GNSS offsets [Melgar et al., 2016 Geophysical Research Letters]. Although GNSS won’t capture landslides or other offshore processes for which on-land GNSS has little resolution, the rapidity of the method in characterizing tsunami excitation, compared with the 10–20 minutes required by global tide gauge and seismic networks and by NOAA’s tsunami-specific Deep-Ocean Assessment and Reporting of Tsunamis (DART) buoy system, offers a dramatic potential improvement in response time for local tsunamis that can inundate coastlines within 5–15 minutes of an earthquake.

Natural hazards monitoring using GNSS isn’t limited to just solid Earth processes. Other measurable quantities, such as tropospheric water content, are estimated in real time with GNSS and are now being used to constrain short-term weather forecasts. Likewise, real-time estimates of ionospheric electron content from GNSS can help identify ionospheric storms (space weather) and in mapping tsunami-excited gravity waves in the ionosphere to provide a more direct measurement of the propagating tsunami as it crosses oceanic basins.

A Future of Unimaginable Potential

Many resources beyond the rapid proliferation of GNSS networks themselves have contributed to making global GNSS hazards monitoring a reality. Unlike seismic sensors that measure ground accelerations or velocities directly, GNSS positioning relies on high-accuracy corrections to the orbits and clocks broadcast by satellites. These corrections are derived from continuous analyses of global networks of ground stations. Similarly, declining costs of continuous telemetry have facilitated multiconstellation GNSS processing, using the vast investments in international satellite constellations to further improve the precision and reliability of real-time GNSS measurements of ground displacements.

In the future, few large earthquakes in the western United States will escape nearly instantaneous measurement by real-time GNSS. Throughout the seismically active Americas, from Alaska to Patagonia, numerous GNSS networks in addition to NOTA now operate, leaving big earthquakes without many places to hide. Mexico operates several GNSS networks, as do Central and South American nations from Nicaragua to Chile. Around the Pacific Rim, Japan, New Zealand, Australia, and Indonesia all operate networks that together comprise thousands of ground stations.

In North America, nearly all GNSS networks have open data-sharing policies [Murray et al., 2018]. But a global system for hazard mitigation can be effective only if real-time data are shared among a wider set of networks and nations. The biggest remaining impediment to expanding a global system is increasing the networks whose data are available for monitoring. GNSS networks are expensive to deploy and maintain. Many networks are built in whole or in part for land surveying and operate in a cost-recovery mode that generates revenue by selling data or derived positioning corrections through subscriptions. At the current time, just under 3,000 stations are publicly available for hazards monitoring, but efforts are under way to create international data sharing agreements specifically for hazard reduction. The Sendai Framework for Disaster Risk Reduction, administered by the United Nations Office for Disaster Risk Reduction, promotes open data for hazard mitigation [International Union of Geodesy and Geophysics, 2015], while professional organizations, such as the International Union of Geodesy and Geophysics, promote their use for tsunami hazard mitigation [LaBrecque et al., 2019].

The future holds unimaginable potential. In addition to expanding GNSS networks, modern smartphones by the billions are ubiquitous sensing platforms with real-time telemetry that increasingly make many of the same GNSS measurements that dedicated GNSS receivers do. Crowdsourcing, while not yet widely implemented, is one path forward that could use tens of millions of phones, coupled to machine learning methods, to help fill in gaps in ground displacement measurements between traditional sensors.

The potential of GNSS as an important supplement to existing methods for real-time hazards monitoring has long been touted. However, a full real-world test and demonstration of this capability did not occur until the recent Ridgecrest earthquake sequence. Analyses are ongoing, but so far the conclusion is that the technique performed exactly as expected—which is to say, it worked exceedingly well. GNSS-based hazards monitoring has indeed arrived.

Acknowledgments

Development of global GNSS seismic analysis is supported by NASA-ESI grants NNX14AQ40G and 80NSSC19K0359 and USGS Cooperative Agreements G17AC00344 and G19AC00264 to Central Washington University. Data from the Network of the Americas are provided by the Geodetic Facility for the Advancement of Geoscience (GAGE), operated by UNAVCO Inc., with support from the National Science Foundation and NASA under NSF Cooperative Agreement EAR-1724794.

References

Crowell, B. W., et al. (2013), Earthquake magnitude scaling using seismogeodetic data, Geophys. Res. Lett., 40(23), 6,089–6,094, https://doi.org/10.1002/2013GL058391.

International Union of Geodesy and Geophysics (2015), Resolution 4: Real-time GNSS augmentation of the tsunami early warning system, iugg.org/resolutions/IUGGResolutions2015.pdf.

Kong, L. S. L., et al. (2015), Pacific Tsunami Warning System: A Half-Century of Protecting the Pacific 1965–2015, 188 pp., Int. Tsunami Inf. Cent., Honolulu, Hawaii, unesdoc.unesco.org/ark:/48223/pf0000233564.

LaBrecque, J., J. B. Rundle, and G. W. Bawden (2019), Global navigation satellite system enhancement for tsunami early warning systems, in Global Assessment Report on Disaster Risk Reduction, U.N. Off. for Disaster Risk Reduct., Geneva, Switzerland, unisdr.org/files/66779_flabrequeglobalnavigationsatellites.pdf.

Melgar, D., et al. (2016), Local tsunami warnings: Perspectives from recent large events, Geophys. Res. Lett., 43(3), 1,109–1,117, https://doi.org/10.1002/2015GL067100.

Melgar, D., et al. (2019), Real-time high-rate GNSS displacements: Performance demonstration during the 2019 Ridgecrest, CA earthquakes, Seismol. Res. Lett., in press.

Minson, S. E., et al. (2014), Real-time inversions for finite fault slip models and rupture geometry based on high-rate GPS data, J. Geophys. Res. Solid Earth, 119(4), 3,201–3,231, https://doi.org/10.1002/2013JB010622.

Murray, J. R., et al. (2018), Development of a geodetic component for the U.S. West Coast Earthquake Early Warning System, Seismol. Res. Lett., 89(6), 2,322–2,336, https://doi.org/10.1785/0220180162.

Murray, J. R., et al. (2019), Regional Global Navigation Satellite System networks for crustal deformation monitoring, Seismol. Res. Lett., https://doi.org/10.1785/0220190113.

Ruhl, C. J., et al. (2017), The value of real-time GNSS to earthquake early warning, Geophys. Res. Lett., 44(16), 8,311–8,319, https://doi.org/10.1002/2017GL074502.

Ruhl, C. J., et al. (2019), A global database of strong-motion displacement GNSS recordings and an example application to PGD scaling, Seismol. Res. Lett., 90(1), 271–279, https://doi.org/10.1785/0220180177.

See the full article here .

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Earthquake Alert

Earthquake Alert

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

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

Get the app in the Google Play store.

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

Meet The Quake-Catcher Network

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

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

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

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

The primary project partners include:

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

The Earthquake Threat

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

Part of the Solution

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

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

System Goal

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

Current Status

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

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

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

Authorities

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

For More Information

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

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

Please help promote STEM in your local schools.

Stem Education Coalition

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

From Curiosity: “An Australian Crater Could Force Us to Rethink How We Judge a Planet’s Age”

Curiosity Makes You Smarter

From From Curiosity

December 20, 2019
Elizabeth Howell

Wolfe Creek Crater: the second largest meteor impact site in the world. Dainis Dravins – Lund Observatory, Sweden.

A rock the size of a semitrailer that smacked Australia more than 100,000 years ago could help us better understand the universe. Astronomers just recalculated the age of an ancient desert crater [Meteoritics & Planetary Science] and discovered that it’s much younger than previously thought. By studying craters on Earth, we can better estimate how often comets and meteorites smacked into worlds around our solar system, thereby calculating their ages — and based on this work, we may have to rethink everything we know.

Younger Than It Looks

The scar of that ancient collision in Australia is called Wolfe Creek Crater, and it’s rather large, having been formed by a meteorite that was likely 50 feet (15 meters) in diameter. The object slammed into the desert and created a divot that’s been deemed the second largest crater on Earth from which fragments of the meteorite were recovered. Craters often disappear underwater or via geologic activity, so we’re lucky to have this find available to us.

Scientists initially pegged the crater as 300,000 years old, putting it at about the same age as the human species. But the new estimate suggests it’s actually quite a bit younger, at only 120,000 years old, dating back to a warmer period on Earth known as the Eemian interglacial period. (On a side note, the Eemian is interesting to scientists studying climate change today, as some studies suggest our Earth nowadays is as warm as it was way back then.)

How did this new age estimate arise? It was probably in part due to the fact that we have better scientific equipment than we did before. Also, researchers used two independent dating techniques: exposure dating, which estimates how long the sediment has been exposed to cosmic rays on the Earth’s surface, and optically stimulated luminescence, which measures how long ago sediment — in this case, sand buried after the impact — was last exposed to sunlight.

“Results from the two dating techniques mutually support each other within the same age range,” said lead author Tim Barrows in a statement.

Counting Craters

Re-dating the crater in Australia has implications that could rock our solar system. There are planets and moons and tiny worlds with rocky surfaces all over our planetary neighborhood, some of the more famous being Mercury, the Moon, and Pluto. Astronomers estimate the age of their surfaces by using a technique called crater counting, which is exactly what it sounds like: They count the number of craters in an area and compare that number with an estimate of how often a small world smacks into the surface.

Simply put, if scientists find a crater that’s younger than expected, that might mean that the rate of objects hitting Earth (and other worlds) slightly increases. With this new measurement, the research team estimates that large objects smack into our planet about once every 180 years or so. In roughly the last century, we know of two such events: an object that flattened 800 square miles (2,000 square kilometers) of forest in Tunguska, Siberia in 1908, and another that shattered glass and injured people when it broke up over the Russian town Chelyabinsk in 2013.

NASA is, of course, on the case with a fleet of telescopes scanning the sky for any possible threats to Earth. Fortunately, they’ve found nothing pressing that could flatten a city, although they continue the search just in case — and they’re also aware that smaller objects (like Chelyabinsk) can still sneak through since they’re below the detection threshold of some telescopes. However, don’t lose any sleep yet. The agency will let us know if they find something worrying.

In the meantime, the larger implication to take from this study is that the ages of craters all over the solar system may have to be reconsidered. The famous Meteor Crater in Arizona, for example, got a similar treatment from these researchers. They calculated that it’s likely to be 61,000 years old, which is about 10,000 years younger than previously estimated. So it will be interesting to see how this changes our understanding of ancient climates and life on our own planet — and on other worlds

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

Curiosity Makes You Smarter

Curiosity is on a mission to make learning easier and more fun than it has ever been. Our goal is to ignite curiosity and inspire people to learn. Each day, we create and curate engaging topics for millions of lifelong learners worldwide.

Experience Curiosity on our website, through our apps and across social media. We designed Curiosity with your busy life in mind. Our editors find interesting and important topics that you’ll want to know more about, and introduce you to the best ways to keep learning.

We hope you make Curiosity part of your daily digital diet. Never stop learning!

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

From temblor

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

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

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

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

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

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

More to come

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

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

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

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

Unsurprising, naturally occurring earthquakes

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

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

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

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

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

An opportunity for advancement

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

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

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

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

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

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

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

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

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

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

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

See the full article here .

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Please help promote STEM in your local schools.

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Earthquake Alert

Earthquake Alert

Earthquake Network project

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

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

Get the app in the Google Play store.

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

Meet The Quake-Catcher Network

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

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

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

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

The primary project partners include:

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

The Earthquake Threat

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

Part of the Solution

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

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

System Goal

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

Current Status

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

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

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

Authorities

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

For More Information

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

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

From Caltech via Science Alert: “Scientists Have Officially Found a Mineral Never Before Seen in Nature”

From Caltech

via

Science Alert

25 DEC 2019
PETER DOCKRILL

The Wedderburn meteorite. (Museums Victoria/CC BY 4.0)

It was found along the side of a road in a remote Australian gold rush town. In the old days, Wedderburn was a hotspot for prospectors – it occasionally still is – but nobody there had ever seen a nugget quite like this one.

The Wedderburn meteorite, found just north-east of the town in 1951, was a small 210-gram chunk of strange-looking space rock that fell out of the sky. For decades, scientists have been trying to decipher its secrets, and researchers just decoded another.

In a study published in August [American Mineralogist] this year, led by Caltech mineralogist Chi Ma, scientists analysed the Wedderburn meteorite and verified the first natural occurrence of what they call ‘edscottite’: a rare form of iron-carbide mineral that’s never been found in nature.

Since the Wedderburn meteorite’s spacey origins were first identified, the distinctive black-and-red rock has been examined by numerous research teams – to the extent that only about one-third of the original specimen still remains intact, held within the geological collection at Museums Victoria in Australia.

The rest has been taken away in a series of slices, extracted to analyse what the meteorite is made from. Those analyses have revealed traces of gold and iron, along with rarer minerals such as kamacite, schreibersite, taenite, and troilite. Now we can add edscottite to that list.

The edscottite discovery – named in honour of meteorite expert and cosmochemist Edward Scott from the University of Hawaii – is significant because never before have we confirmed that this distinct atomic formulation of iron carbide mineral occurs naturally.

Such a confirmation is important, because it’s a pre-requisite for minerals to be officially recognised as such by the International Mineralogical Association (IMA).

A synthetic version of the iron carbide mineral has been known about for decades – a phase produced during iron smelting.

But thanks to the analysis by Chi Ma and UCLA geophysicist Alan Rubin, edscottite is now an official member of the IMA’s mineral club, which is more exclusive than you might think.

“We have discovered 500,000 to 600,000 minerals in the lab, but fewer than 6,000 that nature’s done itself,” Museums Victoria senior curator of geosciences Stuart Mills, who wasn’t involved with the new study, told The Age.

As for how this sliver of natural edscottite ended up just outside of rural Wedderburn can’t be known for sure, but according to planetary scientist Geoffrey Bonning from Australian National University, who wasn’t involved with the study, the mineral could have formed in the heated, pressurised core of an ancient planet.

Long ago, this ill-fated, edscottite-producing planet could have suffered some kind of colossal cosmic collision – involving another planet, or a moon, or an asteroid – and been blasted apart, with the fragmented chunks of this destroyed world being flung across time and space, Bonning told The Age.

Millions of years later, the thinking goes, one such fragment landed by chance just outside Wedderburn – and our understanding of the Universe is the richer for it.

Scanning electron microscopy image (colorized) showing edscottite in the polished Wedderburn section from the UCLA Meteorite Collection. Image credit: Ma & Rubin, doi: 10.2138/am-2019-7102.

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

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

Caltech campus

From The New York Times: “A 3D Encounter With a Violent Volcano’s Underbelly”

From The New York Times

Dec. 18, 2019
Robin George Andrews

Lava flows on Réunion Island from Piton de la Fournaise, one of the world’s most active volcanoes, during a 2015 eruption.Credit RICHARD BOUHET/AFP via Getty Images

Réunion, a French island in the western Indian Ocean, is a jigsaw of two massive shield volcanoes. The younger, Piton de la Fournaise or “peak of the furnace,” is a furious factory of lava, erupting every eight months on average over the last four decades.

The Piton de la Fournaise volcano on Réunion Island. http://www.brianiannone.com/

That hellish environment makes it an ideal real-world laboratory for studying the internal viscera of volcanoes, about which scientists know surprisingly little. The more they map out, the better they grow to understand why, how and when volcanoes all over the world will next erupt.

In a study published this month in Scientific Reports, volcanologists reported using a novel technique to map out 58 square miles of Piton de la Fournaise’s shadowy underworld. Their survey revealed a 3D view of its insides, from the plumbing network of superheated hydrothermal fluids to scores of faults that allow magma to sneak up to the surface during eruptions.

The success of this technique on Réunion means that it could be deployed elsewhere, said Marc Dumont, a geophysicist at the Sorbonne University in Paris and the lead author of the study, from lava effusing mountains like Hawaii’s Kilauea to the more explosive peaks in the volcanic spine running up America’s Pacific Northwest.

Lava erupts from a fissure in the Leilani Estates neighbourhood near Pahoa on the island of Hawaii, on May 24. (Grace Simoneau/FEMA via Associated Press)

Piton de la Fournaise is a byzantine volcano, comprehensively monitored by scientists as it is regularly modified by eruptions. Spidery tendrils of magma escape through lines of weakness. When molten material meets the groundwater cycling through the volcano’s uppermost segments, powerful explosions can happen without warning, much like the lethal detonations that recently rocked New Zealand’s White Island. Old faults can suddenly slip and cause parts of the volcano to catastrophically collapse.

These features control how future eruptions manifest, so finding out where they are is of paramount importance.

An example of the 3D models produced by the research.Credit via Marc Dumont

One way to locate these subterranean features is to use instruments to see how well the rocks below conduct electricity. Scorching, circulating water is highly conductive. Old volcanic rock that has been degraded by it has water inside its Swiss cheese-like holes, making it relatively conductive. Newly cooled, structurally sound lava flows are much more electrically resistant.

Deploying electrical resistivity-detecting instruments on an active volcano can be both dangerous and time consuming. Often, expeditions must choose between a high-resolution underground map of a small area or a low-resolution map of a larger space.

Scientists had previously traipsed across the Piton de la Fournaise by foot, deploying equipment to reveal parts of its internal structure. To speed things up, they took to a helicopter.

Hewing disquietingly close to the volcano over four days in 2014, the helicopter’s winch held a sizable hoop that could electrically excite the rocks below. In response, electromagnetic threads snaked back up from the volcano, which were detected by the helicopter. These invisible strings differed, depending on the properties of the rocks, which allowed scientists to identify individual ingredients and layers of Réunion’s youthful volcanic cake down to a depth of 3,300 feet.

Scientists were previously aware of the existence of some of the volcano’s rift zones, faults and fluid networks. But they now have a 3D schematic providing an unparalleled peek into the volcano’s active subsurface, showing with precision where its magmatic appendages and pathways, rocky scars and hydrothermal pipes are in relation to each other.

“Our continuing ability to image the internal structure of volcanoes in 3D is revolutionizing how we understand volcanism,” said Sam Mitchell, a submarine volcanologist not involved with the work, and who recently joined an aquatic voyage to peer into the heart of a massive underwater volcano near Oregon. No matter which volcano is being mapped, he said, the goal of these projects is the same: to identify hazards and save lives.

See the full article here .

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

Please help promote STEM in your local schools.

Stem Education Coalition

From Caltech: “Scientists Identify Almost 2 Million Previously “Hidden” Earthquakes”

From Caltech

April 18, 2019 [Just found this is a search]
Robert Perkins
(626) 395‑1862
rperkins@caltech.edu

A closer look at seismic data from 2008–17 expands Southern California’s earthquake catalog by a factor of 10.

Seismic activity associated with the Cahuilla earthquake swarm in Southern California’s Anza Valley. Filling out the earthquake catalogue using template matching shows the swarm in greater detail. The color of each seismic event records its depth, and so the rainbow-like appearance of the swarm indicates the shallow-to-deep slant of the fault, not previously visible from earlier data.

Pouring through 10 years’ worth of Southern California seismic data with the scientific equivalent of a fine-tooth comb, Caltech seismologists have identified nearly two million previously unidentified tiny earthquakes that occurred between 2008 and 2017.

Their efforts, published online by the journal Science on April 18, expand the earthquake catalog for that region and period of time by a factor of 10—growing it from about 180,000 recorded earthquakes to more than 1.81 million. The new data reveal that there are about 495 earthquakes daily across Southern California occurring at an average of roughly three minutes apart. Previous earthquake cataloging had suggested that approximately 30 minutes would elapse between seismic events.

This 10-fold increase in the number of recorded earthquakes represents the cataloging of tiny temblors, between negative magnitude 2.0 (-2.0) and 1.7, made possible by the broad application of a labor-intensive identification technique that is typically only employed on small scales. These quakes are so small that they can be difficult to spot amid the background noise that appears in seismic data, such as shaking from automobile traffic or building construction.

“It’s not that we didn’t know these small earthquakes were occurring. The problem is that they can be very difficult to spot amid all of the noise,” says Zachary Ross, lead author of the study and postdoctoral scholar in geophysics, who will join the Caltech faculty in June as an assistant professor of geophysics. Ross collaborated with Egill Hauksson, research professor of geophysics at Caltech, as well as Daniel Trugman of Los Alamos National Laboratory and Peter Shearer of Scripps Institution of Oceanography at UC San Diego.

To overcome the low signal-to-noise ratio, the team turned to a technique known as “template matching,” in which slightly larger and more easily identifiable earthquakes are used as templates to illustrate what an earthquake’s signal at a given location should, in general, look like. When a likely candidate with the matching waveform was identified, the researchers then scanned records from nearby seismometers to see whether the earthquake’s signal had been recorded elsewhere and could be independently verified.

Using powerful computers and a technique called template matching, scientists at Caltech have identified millions of previously unidentified tiny earthquakes. The new data reveal that there are about 495 earthquakes daily across Southern California, occurring at an average of roughly three minutes apart. This graphic shows the earthquakes recorded near Cahuilla, California from 2016-2017.

Template matching works best in regions with closely spaced seismometers, since events generally only cross-correlate well with other earthquakes within a radius of about 1 to 2 miles, according to the researchers. In addition, because the process is computationally intensive, it has been limited to much smaller data sets in the past. For the present work, the researchers relied on an array of 200 powerful graphics processing units (GPUs) that worked for weeks on end to scan the catalog, detect new earthquakes, and verify their findings.

However, the findings were worth the effort, Hauksson says. “Seismicity along one fault affects faults and quakes around it, and this newly fleshed-out picture of seismicity in Southern California will give us new insights into how that works,” he says. The expanded earthquake catalog reveals previously undetected foreshocks that precede major earthquakes as well as the evolution of swarms of earthquakes. The richer data set will allow scientists to gain a clearer picture of how seismic events affect and move through the region, Ross says.

“The advance Zach Ross and colleagues has made fundamentally changes the way we detect earthquakes within a dense seismic network like the one Caltech operates with the USGS. Zach has opened a new window allowing us to see millions of previously unseen earthquakes and this changes our ability to characterize what happens before and after large earthquakes,” said Michael Gurnis, Director of the Seismological Laboratory and John E. and Hazel S. Smits Professor of Geophysics

See the full article here .

Earthquake Alert

Earthquake Alert

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

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

Get the app in the Google Play store.

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

Meet The Quake-Catcher Network

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

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

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

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

The primary project partners include:

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

The Earthquake Threat

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

Part of the Solution

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

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

System Goal

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

Current Status

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

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

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

Authorities

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

For More Information

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

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

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

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