Advancing earthquake science worldwide
5 August 2020–The heights of La Soufrière de Guadeloupe volcano can be hellish, sweltering at more than 48 degrees Celsius (120 degrees Fahrenheit) and swathed in billows of acidic gas. Researchers would like to monitor gas and steam eruptions at its summit, to learn more about the volcano’s explosive potential, … Continue Reading »
29 July 2020–Aaron Lojewski, who leads aurora sightseeing tours in Alaska, was lucky enough to photograph a “eruption” of brilliant pink light in the night skies one night in February. The same perturbations of the Earth’s magnetic field that lit up the sky for Lojewski’s camera were also captured by … Continue Reading »
21 July 2020–The depth of a hydraulic fracturing well in Oklahoma, among other factors, increases the probability that fracking will lead to earthquake activity, according to a new report in the Bulletin of the Seismological Society of America. The researchers hope their findings, published as part of an upcoming BSSA … Continue Reading »
Dear SSA Community: As a Society, we seek to do all we can to make science accessible to all. That goal has inspired a new task force to address diversity and inclusion within our community. Chaired by Aaron Velasco, professor of geological sciences and computational sciences at the University of … Continue Reading »
FROM BILL WALTER, PRESIDENT OF SSA 9 July 2020 — Seismology is a global endeavor, and the international scientific community benefits from a free exchange of people as well as ideas. The Administration’s recent proposal to limit participation by international students in US degree programs would be tragic, both for … Continue Reading »
7 July 2020 – Today the Seismological Society of America announced its search for the next Editor-in-Chief (EIC) of Bulletin of the Seismological Society of America (BSSA), its flagship, peer-reviewed international journal. The journal is key to the Society meeting its core mission to advance earthquake science worldwide and to … Continue Reading »
30 June 2020–Adding relatively inexpensive magnetometers to seismic stations across Alaska could help track geomagnetic storms as well as improve the performance of the seismometers, researchers report in the Bulletin of the Seismological Society of America. As solar winds—plasma ejected from the Sun—interact with the Earth’s magnetic field at the … Continue Reading »
8 June 2020–SSA is pleased to announce the recipients of several of the Society’s awards for 2020. The Harry Fielding Reid Medal, the Charles F. Richter Early Career Award, the Frank Press Public Service Award and the SSA Distinguished Service Award are among the highest honors conferred by the Society. … Continue Reading »
I write you as the president of SSA, a global society of Earth scientists that values the diversity of voices and backgrounds in our community. Along with the rest of the SSA leadership, I am disturbed and disheartened by the senseless killing of George Floyd in Minneapolis. Recent racist events … Continue Reading »
13 May 2020–Three hundred-year-old administrative documents from the Roman government, granting residents permission to repair damage to their buildings, can help modern-day seismologists calculate intensities for a notable sequence of earthquakes that struck central Italy in 1703. Details gleaned from these “Lettere Patenti” offer a unique glimpse at the geographical … Continue Reading »
6 May 2020–Yes, there’s a prize for the most beautiful flower-filled float in the Rose Parade each year, but how about a prize for the most ground-shaking marching band? According to a new study, the 2020 honors go to the Southern University and A&M College, followed closely by the hometown … Continue Reading »
28 April 2020–Hydraulic fracturing for oil and gas production can trigger earthquakes, large and small. A new approach to managing the risk from these quakes could help operators and regulators hit the brakes early enough to prevent nuisance and reduce the chance of property damage and injury. The approach, published … Continue Reading »
14 April 2020–At the regional level and worldwide, the occurrence of large shallow earthquakes appears to follow a mathematical pattern called the Devil’s Staircase, where clusters of earthquake events are separated by long but irregular intervals of seismic quiet. The finding published in the Bulletin of the Seismological Society of … Continue Reading »
7 April 2020–In complex fault zones, multiple seemingly disconnected faults can potentially rupture at once, increasing the chance of a large damaging earthquake. Recent earthquakes including the 1992 Landers, 1999 Hector Mine and 2019 Ridgecrest earthquakes in California, among others, ruptured in this way. But how can seismologists predict whether … Continue Reading »
30 January 2020–Nearly 40 years ago, analog data tapes faithfully recorded intense seismic activity in the two months before the historic eruption of Mount St. Helens in Washington State in May 1980. It took some lengthy and careful restoration efforts—including a turn in a kitchen oven for some of the … Continue Reading »
28 January 2020–Earthquakes along a complex series of faults in the upper plate of New Zealand’s northern Hikurangi Subduction Margin were responsible for coastal uplift in the region, according to a new evaluation of local marine terraces. The findings, reported in the Bulletin of the Seismological Society of America, could … Continue Reading »
22 January 2020–The 2019 Ridgecrest earthquake sequence, which startled nearby California residents over the 4 July holiday with magnitude 6.4 and magnitude 7.1 earthquakes, included 34,091 earthquakes overall, detailed in a high-resolution catalog created for the sequence. The catalog, developed by David Shelly at the U.S. Geological Survey in Golden, … Continue Reading »
7 January 2020–The magnitude of the Great Lisbon Earthquake event, a historic and devastating earthquake and tsunami that struck Portugal on All Saints’ Day in 1755, may not be as high as previously estimated. In his study published in the Bulletin of the Seismological Society of America, Joao F. B. … Continue Reading »
16 December 2019–The term “public service” has broad meaning when it comes to the Frank Press Public Service Award, which the Seismological Society of America created to honor outstanding efforts on behalf of seismology and public safety. In part, the award has a broad reach due to the trailblazing and … Continue Reading »
3 December 2019–Each hair-thin glass fiber in a buried fiber optic cable contains tiny internal flaws—and that’s a good thing for scientists looking for new ways to collect seismic data in places from a busy urban downtown to a remote glacier. In Seismological Research Letters, California Institute of Technology seismologist … Continue Reading »
20 November 2019–The terms may seem interchangeable to a layperson, but “hazard” and “risk” mean very different things in earthquake science. A seismic hazard is a natural phenomenon such as the level of ground shaking caused by an earthquake. Seismic risk, on the other hand, refers to the probability that … Continue Reading »
19 November 2019–Hand-dug trenches around Leigh Lake in Grand Teton National Park in Wyoming reveal evidence for a previously unknown surface-faulting earthquake in along the Teton Fault—one occurring about 10,000 years ago. Together with evidence from the site of a second earthquake that ruptured around 5,900 years ago, the findings … Continue Reading »
6 November 2019–The season that an earthquake occurs could affect the extent of ground failure and destruction that the event brings, according to a new look at two historical earthquakes that occurred about 100 years ago near Almaty, Kazakhstan. In a paper published in Seismological Research Letters, researchers conclude that … Continue Reading »
31 October 2019–The Earthquake Engineering Research Institute (EERI) and the Seismological Society of America (SSA) are pleased to announce that Julian J. Bommer, a Senior Research Investigator at Imperial College London, is the 2020 recipient of the William B. Joyner Lecture Award. Bommer will deliver the Joyner Lecture at the … Continue Reading »
Isabel Hong has always been enthralled with earthquakes. As an elementary student growing up in Washington state, she made frequent leaps under her school desk for earthquake drills. And when an earthquake finally rocked her hometown, she felt prepared. “I wasn’t fearful. I knew just what to do,” recalled Hong, … Continue Reading »
29 October 2019–By combining models of magnitude 9 to 9.2 earthquakes on the Cascadia Subduction Zone with geological evidence of past coastal changes, researchers have a better idea of what kind of megathrust seismic activity was behind the 1700 Cascadia earthquake. The analysis by Erin Wirth and Arthur Frankel of … Continue Reading »
23 October 2019–Although he grew up in Switzerland and received his Ph.D. at the University of Basel, much of Max Suter’s career has been centered on Mexico. From the Trans-Mexican Volcanic Belt in central Mexico to the Basin and Range province of northwestern Mexico, his research has identified and characterized … Continue Reading »
22 October 2019–Major landslides triggered by the 1964 magnitude 9.2 Great Alaska earthquake responded to, but were not reactivated by, the magnitude 7.1 Anchorage earthquake that took place 30 November 2018, researchers concluded in a new study published in Seismological Research Letters. The shaking that accompanied the 2018 earthquake was … Continue Reading »
2 October 2019–The International Monitoring System is the top global seismic network for monitoring nuclear weapon tests around the world. To expand the system’s detection capabilities, however, international monitors should seek out the data, methods and expertise of smaller regional seismic networks. In a paper published as part of an … Continue Reading »
16 September 2019–Earthquake faults have short memories—or at least, that’s what the traditional earthquake cycle model suggests. Based on the elastic rebound theory proposed by Harry Fielding Reid after the 1906 San Francisco earthquake, the traditional model assumes that each earthquake in an area occurs independently of one another, and … Continue Reading »
5 September 2019–The eastern Pacific Ocean margin stretching from Mexico to southern Chile offers seismologists a “natural laboratory” in which to study and test ideas about the processes of subduction zones, which are associated with some of the world’s largest recorded earthquakes in the region, as well as phenomena such … Continue Reading »
SSA announces the 2020 election to select four new members to serve three-year terms on the Board of Directors. The seven candidates and their statements are presented below, in alphabetical order by last name; in order by last name, these candidates are Annemarie Baltay, Susan Bilek, Matthew Gerstenberger, Hiroshi Kawase, … Continue Reading »
15 August 2019–Seismic networks depend on good instrumentation. But testing sensitive seismic instruments to make sure they’re working right can be a challenge, as Adam Ringler, a physical scientist with the U.S. Geological Survey, knows well. “Seismometers aren’t only sensitive to ground motion, which you want, they’re also sensitive to … Continue Reading »
15 July 2019 –Joan Latchman, a seismologist at The University of the West Indies Seismic Research Centre, was born in Trinidad and Tobago and grew up just a 15-minute walk from the Centre – then known as the Seismic Research Unit. At the time, the Centre had a low profile, … Continue Reading »
18 June 2019–The unusual appearance of deep-sea fish like the oarfish or slender ribbonfish in Japanese shallow waters does not mean that an earthquake is about to occur, according to a new statistical analysis. The study published in the Bulletin of the Seismological Society of America contradicts long-held Japanese folklore … Continue Reading »
12 June 2019–Researchers who took a closer look at a 1995 tsunami in the Gulf of Elat-Aqaba, at the northeastern tip of the Red Sea, say that the gulf’s surrounding countries should prepare for future tsunami hazards in the economically developing vital region. A team of scientists led by Amos … Continue Reading »
11 June 2019–A comprehensive catalog of earthquake sequences in Texas’s Fort Worth Basin, from 2008 to 2018, provides a closer look at how wastewater disposal from oil and gas exploration has changed the seismic landscape in the basin. In their report published in the Bulletin of the Seismological Society of … Continue Reading »
11 June 2019–New mechanical modeling of a network of active strike-slip faults in California’s Imperial Valley suggests the faults are continuously linked, from the southern San Andreas Fault through the Imperial Fault to the Cerro Prieto fault further to the south of the valley. Although more studies are needed to … Continue Reading »
23 May 2019–SSA is pleased to announce the recipients of several of the Society’s awards for 2019. The Harry Fielding Reid Medal, the Charles F. Richter Early Career Award and the Frank Press Public Service Award are among the highest honors conferred by the Society. The Reid Medal recipient is Karen Fischer of … Continue Reading »
26 April 2019–A day after the 30 November 2018 magnitude 7 earthquake in Anchorage, Alaska, U.S. Geological Survey scientists Robert Witter and Adrian Bender had taken to the skies. The researchers were surveying the region from a helicopter, looking for signs of ground failure from landslides to liquefaction. As Witter … Continue Reading »
26 April 2019–Using a dense sensor network that scanned the United States between 2003 and 2014, researchers have identified areas within the country marked by a persistent seismic signal caused by industrial processes. At the 2019 SSA Annual Meeting, Omar Marcillo of Los Alamos National Laboratory said that he and … Continue Reading »
26 April 2019–About 16.7 million years ago, the Columbia River flood basalt event covered much of eastern Oregon, parts of western Idaho and southern Washington state. The massive outpouring of basalt lava, covering about 63,000 square miles of the Pacific Northwest, is thought to have originated from the Yellowstone volcanic … Continue Reading »
26 April 2019–In the past decade scientists have been experimenting with metamaterials, artificial materials designed with periodic internal structures to give them properties not found in natural materials. Depending on their internal geometry and composition, researchers have found that they can control waves propagating through some of these materials, filtering … Continue Reading »
25 April 2019–Small earthquakes in Ohio, Pennsylvania, West Virginia, Oklahoma and Texas can be linked to hydraulic fracturing wells in those regions, according to researchers speaking at the SSA 2019 Annual Meeting. While relatively rare compared to earthquakes caused by wastewater disposal in oil and gas fields in the central … Continue Reading »
25 April 2019–Ever since Hawaii’s Kilauea stopped erupting in August 2018, ceasing activity for the first time in 35 years, scientists have been wondering about the volcano’s future. Its similarities to the Hawaiian seamount Lo`ihi might provide some answers, according to Jacqueline Caplan-Auerbach at Western Washington University. In her presentation … Continue Reading »
25 April 2019–A spring surge of meltwater, seeping through vertically tilted layers of rock, caused a seismic swarm near California’s Long Valley Caldera in 2017, according to research presented at the 2019 SSA Annual Meeting. The unusual event prompted U.S. Geological Survey researcher Emily Montgomery-Brown and her colleagues to look … Continue Reading »
24 April 2019–Researchers at the SSA 2019 Annual Meeting are discussing proposed revisions to the National Seismic Hazard Model (NSHM). The draft report concludes that there could be significantly increased ground shaking across many locations in the central and eastern United States, as well as four urban areas built on … Continue Reading »
24 April 2019–The central Salish Sea of the Pacific Northwest is bounded by two active fault zones that could trigger rockfalls and slumps of sediment that might lead to tsunamis, according to a presentation at the 2019 SSA Annual Meeting. These tsunamis might be directed toward the islands of San … Continue Reading »
24 April 2019–Using ground motions generated for a range of simulated magnitude 9 earthquakes in the Pacific Northwest, researchers are testing how well reinforced concrete walls might stand up under such seismic events. The walls may not fare so well, especially within the city of Seattle, said University of Washington … Continue Reading »
23 April 2019–NASA’s InSight mission has detected its first likely “quake” on Mars. At the opening of the 2019 SSA Annual Meeting, InSight Principal Investigator Bruce Banerdt of NASA’s Jet Propulsion Laboratory described the finding by the lander and discussed the hopeful future of Martian seismology. Watch the video of … Continue Reading »
22 April 2019–This year’s SSA Annual Meeting includes three joint sessions with the Seismological Society of Japan, continuing a long-standing partnership with SSJ and SSA members. The three session topics—Machine Learning in Seismology, Next Generation Earthquake Early Warning Systems: Advances, Innovations and Applications and The Science of Slow Earthquakes from … Continue Reading »
Earlier this year, Los Angeles became one of the first cities in the country to roll out ShakeAlert – a dedicated earthquake early warning system. Advanced warning of an earthquake has long been a goal for everyone from seismologists to local governments. Especially in cities like Los Angeles, located along … Continue Reading »
[讀中文] 5 April 2019–Two moderate-sized earthquakes that struck the southern Sichuan Province of China last December and January were probably caused by nearby fracking operations, according to a new study published in Seismological Research Letters. The December 2018 magnitude 5.7 and the January 2019 magnitude 5.3 earthquakes in the South … Continue Reading »
3 April 2019–There have been no major ground rupturing earthquakes along California’s three highest slip rate faults in the past 100 years. A new study published in Seismological Research Letters concludes that this current “hiatus” has no precedent in the past 1000 years. U.S. Geological Survey researchers Glenn Biasi and … Continue Reading »
26 March 2019–A new high-resolution map of a poorly known section of the northern San Andreas Fault reveals signs of the 1906 San Francisco earthquake, and may hold some clues as to how the fault could rupture in the future, according to a new study published in the Bulletin of … Continue Reading »
1 March 2019–With a growing wealth of seismic data and computing power at their disposal, seismologists are increasingly turning to a discipline called machine learning to better understand and predict complicated patterns in earthquake activity. In a focus section published in the journal Seismological Research Letters, researchers describe how they … Continue Reading »
15 February 2019–Hourly water level records collected from tide gauges can be used to measure land uplift caused by episodic tremor and slip of slow earthquakes in the Cascadia Subduction Zone, according to a new report in the Bulletin of the Seismological Society of America. Global Positioning System (GPS) data … Continue Reading »
By mathematically modeling the movements of a locomotive that toppled from the tracks north of San Francisco during the city’s infamous 1906 earthquake, researchers have calculated a lower limit on the earthquake ground motion at the spot of the tipped train. Their report in the journal Seismological Research Letters concludes … Continue Reading »
The Seismological Society of America held its Board of Directors election on Friday, 4 January 2019. The following nominees for Director were elected to a three-year term beginning in April 2019 at the SSA Annual Meeting in Seattle: Heather DeShon, Associate Professor, Southern Methodist University Heather DeShon’s principal fields of … Continue Reading »
SSA has added a new technical session for the 2019 SSA Annual Meeting: “The InSight Mission – Seismology on Mars and Beyond.” The deadline to submit abstracts to this special session is Thursday, 17 January at 5 p.m. Pacific. Session Description: The InSight mission landed on Mars on November 26, … Continue Reading »
The Consortium of Strong Motion Observation Systems (COSMOS), Earthquake Engineering Research Institute (EERI) and SSA have selected Yousef Bozorgnia as the 2019 recipient of the Bruce Bolt Medal. Bozorgnia, a professor at the University of California, Los Angeles in both the Department of Civil and Environmental Engineering and the John … Continue Reading »
28 December 2018–A low-cost earthquake early warning system provided a map of expected ground shaking around the epicenter of February’s magnitude 6.4 Hualien earthquake within two minutes of the mainshock’s start, according to a new study by seismologists at the National Taiwan University, which deployed the system. The predicted shake … Continue Reading »
SSA announced 21 student and international members will receive travel grants to attend the Annual Meeting in Seattle, to be held 23–26 April 2019. These travel grants are made possible by member contributions to the Kanamori Fund, the General Fund and the Student Travel Fund. Grant recipients receive complimentary conference registration and a cash stipend for transportation, food and lodging. The 21 recipients of … Continue Reading »
18 December 2018–A closer look at small earthquakes that took place at the Oroville Dam in California’s Sierra Nevada foothills in February 2017—near the time when the dam’s spillway failed—suggest that the seismic activity was related to reservoir discharge that opened and closed fractures in the rock below the spillway. … Continue Reading »
11 December 2018–Using data gleaned from historical reports, researchers have now identified the sources of some of the most destructive Indonesian earthquakes in Java, Bali and Nusa Tenggara, using these data to independently test how well Indonesia’s 2010 and 2017 seismic hazard assessments perform in predicting damaging ground motion. The … Continue Reading »
SAN FRANCISCO (3 December 2018) – The Seismological Society of America (SSA) announced today the appointment of Allison Bent, a research seismologist with Natural Resources Canada, as editor-in-chief of Seismological Research Letters (SRL). Accessible by all SSA members and available in more than 1,300 academic, government and corporate institutions worldwide, … Continue Reading »
6 November 2018–A bleached fringe of dead marine algae, strung along the coastlines of two islands off the coast of Chile, offers a unique glimpse at how the land rose during the 2016 magnitude 7.6 Chiloé earthquake, according to a new study in the Bulletin of the Seismological Society of … Continue Reading »
31 October 2018–The depth of the rock layer that serves as the disposal site for wastewater produced during unconventional oil extraction plays a significant role in whether that disposal triggers earthquakes in the U.S., according to a new study that takes a broad look at the issue. The research published … Continue Reading »
16 October 2018–Underwater explosions detonated by the U.S. Navy to test the sturdiness of ships’ hulls have provided seismologists with a test opportunity of their own: how much can we know about an underwater explosion from the seismic and acoustic data it generates? In a study published in the Bulletin … Continue Reading »
26 September 2018–The epicenter of the 3 September 2017 nuclear test explosion in North Korea occurred about 3.6 kilometers northwest of the country’s first nuclear test in October 2006, according to a new high-precision analysis of the explosion and its aftermath. The study published in Seismological Research Letters by Lian-Feng Zhao … Continue Reading »
25 September 2018–The seasonal filling and emptying of reservoirs in India can cause measurable deformation of the surrounding rock, reducing the strength of nearby faults and potentially triggering earthquakes, according to two new papers published in the Bulletin of the Seismological Society of America. Researchers in India used global positioning … Continue Reading »
SSA announces the candidates for the 2019 election to add four members to the Board of Directors. The nominating committee, chaired by Jim Mori, confirmed a slate of six individuals to run for office. The committee included: Jim Mori (Kyoto University) Rachel Abercrombie (Boston University) Gail Atkinson (Western University) Ken … Continue Reading »
22 August 2018–The bright flashes that lit up the evening skies near Detroit, Michigan earlier this year were not the only signs of the meteor that disintegrated in the atmosphere on 17 January 2018. The meteor explosion was also captured by infrasonic microphones and seismometers, offering a rare chance to … Continue Reading »
1 August 2018–Using an array of coffee-can sized geophones deployed for about a month in backyards, golf courses and public parks, researchers collected enough data to allow them to map the depth and shape of the San Gabriel and San Bernardino sedimentary basins of Los Angeles, California. Seismologists think these … Continue Reading »
14 June 2018–SSA is pleased to announce the recipients of several of the Society’s awards for 2018. The Harry Fielding Reid Medal, the Charles F. Richter Early Career Award and the Frank Press Public Service Award are among the highest honors conferred by the Society. The Reid Medal recipient is David M. … Continue Reading »
13 June 2018–Since 2007, the Collaboratory for the Study of Earthquake Predictability or CSEP has been studying earthquake forecast models to find out how well each model stacks up against its competitors, and how well each forecast predicts later seismic activity. At four centers in California, New Zealand, Europe and … Continue Reading »
17 May 2018–SSA plans to hold its annual meeting in San Juan, Puerto Rico in 2022, the society’s new president Peter Shearer announced 14 May at the opening ceremony that welcomed participants to the Seismology of the Americas conference. The 14-17 May gathering in Miami brought together SSA and the … Continue Reading »
17 May 2018–Repeating seismic events—events that have the same frequency content and waveform shapes—may offer a glimpse at the movement of magma and volcanic gases underneath Turrialba and Poas, two well-known active volcanoes in Costa Rica. At the 2018 SSA Annual Meeting, Rebecca Salvage of the Observatorio Vulcanologico y Sismologico … Continue Reading »
17 May 2018–The shape of the continental shelf off the southern Mexican coast played a role in the formation of long-lasting tsunami edge waves that appeared after last September’s magnitude 8.2 earthquake, according to researchers speaking at the SSA 2018 Annual Meeting. Edge waves are coastal waves generated by a … Continue Reading »
17 May 2018–Can altering the amount or rate of fluid injection and production in an oil and gas field or carbon storage site affect induced earthquakes in that field? A physics-based simulation presented at the 2018 SSA Annual Meeting suggests that this type of “active pressure management” can be useful … Continue Reading »
16 May 2018–This spring, researchers will release an expanded database that covers the geometry of most of the world’s subducting slabs, the massive pieces of the Earth’s crust that sink into the mantle at tectonic plate boundaries. Called Slab2, the updated database will help researchers determine the impact of 3-D … Continue Reading »
16 May 2018–Devastating magnitude 8.0 to 9.0 megathrust earthquakes and accompanying tsunamis appear to have hit the U.S. Pacific Northwest and Southwest Canada about every 500 years on average. But some scientists think the recurrence interval between some of these large earthquakes may be shorter—along the lines of every 300 … Continue Reading »
16 May 2018–Last September’s magnitude 8.2 Tehuantepec earthquake and the magnitude 7.1 Puebla-Morelos earthquakes in Mexico led to an intense period of study for Latin American seismologists, with new research on everything from strong motion records to tsunamis generated by the two significant events. The 2018 SSA Annual Meeting devoted … Continue Reading »
16 May 2018–The 2004 Indian Ocean tsunami has researchers reevaluating whether a magnitude 9.0 megathrust earthquake and resulting tsunami might also be a likely risk for the Caribbean region, seismologists reported at the SSA 2018 Annual Meeting. “Before 2004, we thought an earthquake of about 8.0 was about right for … Continue Reading »
16 May 2018–There are more than a million kilometers of underwater telecommunication cables lining the world’s ocean floor. Scientists would like to outfit those cables with environmental sensors—including seismometers—to improve the speed and success of tsunami warnings and to create better models of the Earth’s interior. At the 2018 SSA … Continue Reading »
15 May 2018–Nyiragongo in the Democratic Republic of the Congo is among the world’s most active volcanoes, with a persistent lava lake as one of its defining features. In a talk at the 2018 SSA Annual Meeting, Adrien Oth of the European Center for Geodynamics and Seismology discussed how he … Continue Reading »
[Leer en español] 15 May 2018–New seismic hazard and risk models developed for South America suggest that more than 160 million people—about one-third of the continent’s total population—live in areas with significantly elevated seismic hazard, according to a report discussed at the 2018 SSA Annual Meeting. Risk is greatest in … Continue Reading »
15 May 2018–Record cold temperatures during the winter of 2014 in the Midwestern United States froze large parts of the Great Lakes—and inadvertently offered seismologists a chance to learn more about the seismic signals created by the lakes’ wind-driven waves. The deep freeze stilled the waves and created a period … Continue Reading »
15 May 2018–Scientists monitoring the vibrations of natural rock arches have found that the resonant frequencies of arches undergo dynamic changes from day to day, according to research presented at the 2018 SSA Annual Meeting. University of Utah doctoral student Paul Geimer and colleagues are analyzing these frequency changes to … Continue Reading »
15 May 2018–Almost 70 years later, the man remembers the August day in Playa Rincon, when he clung to the top of an almond tree to survive a tsunami where the waters rushed about 700 meters inland after a magnitude 8.1 earthquake. His recollections and other astonishing eyewitness accounts of … Continue Reading »
Now more than 40 years old, the field of seismic tomography has provided an unprecedented look at the 3D internal structures of the Earth. But as tomography enters its “middle age,” it’s time to take stock, said SSA Past-President Peter Shearer. Shearer, a professor of geophysics at Scripps Institution of … Continue Reading »
13 July 2020–Deep long period (DLP) earthquakes occur close to the base of the crust and contain seismic waveforms with frequencies less than 5 Hz—a phenomenon very different from the high frequency, relatively shallow tectonic activity that most people think of as an earthquake. DLP earthquakes are most often associated … Continue Reading »