Researchers developed a new method to distinguish between small earthquakes and low-yield nuclear explosions in the US West. By comparing local magnitude and coda duration magnitude measurements, seismologists can identify seismic events caused by human activity more accurately.
A magnitude 4.9 earthquake triggered by hydraulic fracturing in a Chinese shale gas field occurred along a fault about one kilometer deep. The event challenges current understanding of seismic risk for shallow faults, highlighting the need to reassess evaluation strategies.
The study found that long-period buildings experienced the most amplification of shaking from the Ridgecrest earthquake, with maximum amplification occurring in the western part of the L.A. basin and the south-central San Fernando Valley. This could result in high-rise buildings in those areas experiencing shaking four times larger tha...
A team of scientists installed an optical seismometer on La Soufrière de Guadeloupe volcano's summit to monitor gas and steam eruptions. The instrument collects data that will be combined with other observations to better understand the volcano's explosive potential.
Researchers have matched seismic signals with aurora displays in Alaska, offering a new way to study magnetic fluctuations. By combining data from all-sky cameras and seismometers, scientists can better understand the link between solar winds and the Earth's magnetic field.
Researchers found a significant link between well depth and seismic probability, suggesting that deeper wells are more likely to trigger earthquakes. The study also revealed that the type of fluid used in hydraulic fracturing, including gel vs. slickwater operations, may affect seismic activity.
Researchers used 'Lettere Patenti' documents to calculate intensities for a 1703 earthquake sequence in central Italy, revealing that the main earthquakes were likely intensity V or VI. The study provides a more realistic view of the earthquakes' impact than historical reports, shedding new light on seismic intensity assessment.
A recent study used fiber optic cables to capture seismic signatures of the Rose Parade, capturing the vibrations of marching bands and floats. The technique, called distributed acoustic sensing (DAS), revealed distinct signals from the parade, including harmonic frequencies corresponding to even-stepping marching bands.
Researchers found that large earthquake sequences are 'burstier' and more difficult to predict than expected, with irregular gaps between event bursts. This finding could impact seismic hazard assessment and the way we evaluate an event's likelihood of repeating soon after a large earthquake.
Researchers have found that fault segments connected at depth can influence earthquake risk and magnitude. A study suggests that a rapid decay in slip at the edge of a fault segment indicates a connection below the surface.
Seismologists have recovered nearly 40-year-old seismic data tapes from the 1980 Mount St. Helens eruption, providing a near-continuous sequence of activity leading up to the May 18th event. The data analysis suggests no significant change in seismic signals that would have hinted at an imminent major eruption.
Researchers found that upper-plate earthquakes, not subduction earthquakes, caused coastal uplift along New Zealand's Northern Hikurangi Margin. Marine terraces at two sites showed different uplift patterns, leading to the mapping of new offshore faults that may contribute to these earthquakes.
A high-resolution catalog of earthquakes from the 2019 Ridgecrest sequence reveals complex rupturing and crosscutting fault structures. The catalog helps researchers understand the triggering and evolution of the sequence, shedding light on the physics and processes involved.
A new study has recalculated the magnitude of the Great Lisbon Earthquake from 8.5 to 9.0 to 7.7 using macroseismic data from Portugal, Spain, and Morocco. The analysis suggests that the earthquake's epicenter was offshore the southwestern Iberian Peninsula and may have involved faulting onshore.
Scientists are exploring the use of fiber optic cables as earthquake sensors due to their potential for accurate seismic data collection. Distributed Acoustic Sensing (DAS) technology uses internal flaws in fibers to detect changes in temperature, strain, or vibrations caused by seismic waves.
New findings published in the Bulletin of the Seismological Society of America extend the history of Teton Fault earthquakes, suggesting multi-section ruptures may have occurred. The study, which analyzed trenches around Leigh Lake, estimates a 10,000-year-old earthquake with a magnitude of 6.6 to 7.2.
Researchers found that a shallow frozen ground layer likely caused more ground failure in the 1911 Kemin earthquake due to its ability to inhibit drainage of pore-pressure excess. The study suggests seismologists should consider seasonality in soil characteristics when making probabilistic liquefaction or ground failure assessments.
Researchers used 3D models of Cascadia megathrust events and geological evidence to recreate the 1700 earthquake's impact on the Pacific Northwest coast. The study suggests that a rupture extending just offshore could cause coastal subsidence, with an estimated magnitude between 8.7 and 9.2.
A new study published in Seismological Research Letters found that deep landslides triggered by the 1964 magnitude 9.2 Great Alaska earthquake were not reactivated by the 2018 magnitude 7.1 Anchorage earthquake. Researchers attributed this to the shorter duration and higher frequency of shaking during the 2018 quake, which likely kept ...
Regional seismic networks in North America contribute to nuclear test monitoring, particularly for low-yield explosions. These networks can detect and locate small seismic events that are difficult for global systems to identify.
Researchers analyzed past major earthquakes in Mexico and Chile to understand earthquake cycles and calculate future seismic hazards. The data also helped develop new ideas about the physical processes involved in seismic rupture, geometry of subduction, and tsunami generation in the region.
A new statistical analysis published in the Bulletin of the Seismological Society of America has found no correlation between deep-sea fish appearances and earthquakes in Japan. Despite long-held folklore suggesting otherwise, researchers have only identified one potentially correlated event out of 336 sightings and 221 earthquakes.
A team of scientists has simulated tsunamis in the Gulf of Elat-Aqaba using a GeoClaw modeling program and concluded that future tsunami hazards are possible. The region's economic importance is heightened by its growing shipping ports, tourism, and water and electrical projects.
A comprehensive catalog of earthquake sequences in the Fort Worth Basin reveals a decrease in seismicity rates since 2014, corresponding to reduced wastewater injection. New faults have become active, and seismicity continues at greater distances from injection wells over time.
Researchers have found that faults in the Imperial Valley are mechanically linked, forming a continuous fault structure. This could increase the likelihood of larger earthquakes in Los Angeles and surrounding counties.
Volcano seismologist Jacqueline Caplan-Auerbach studies Loihi's 1996 eruption for parallels to Kilauea's 2018 activity, suggesting a caldera collapse mechanism. Loihi's recent increase in seismicity may indicate magma replenishment, predicting Kilauea could be quiet for a decade before reactivating.
Researchers have identified areas with persistent seismic signals caused by industrial processes using a dense sensor network spanning the US. The map, developed by Los Alamos National Laboratory, pinpoints prominent sources of industrial activity, including wind farms and large water pumping stations.
Researchers found signs of ground failure, including slumped road ramps and liquefaction, in the aftermath of the 2018 Anchorage earthquake. The study suggests that shaking from the quake did not reactivate past landslides, likely due to its short duration.
Researchers have identified over 600 small earthquakes between magnitude 2.0 and 3.8 in Ohio, Pennsylvania, West Virginia, Oklahoma, and Texas, linked to fracking operations. The study reveals that the depth of the well is a significant factor in predicting likelihood of seismicity.
Researchers are investigating whether metamaterial concept can be scaled up to city size to reduce earthquake damage. Simulations show that structures act as resonators, plucking energy from Rayleigh waves, and optimal building arrangement could reduce damage by decreasing height radially inward.
Researchers found a strong correlation between meltwater runoff and seismic activity in the region, suggesting that seeping water may trigger small earthquakes. The study suggests that the shallow nature of the earthquakes is due to the unique geology of the area, with steeply dipping rock layers acting as a conduit for meltwater.
A recent study suggests that reinforced concrete walls in Seattle may experience up to 11% larger displacement and a higher probability of collapse during magnitude 9 earthquakes due to basin effects. The research highlights the need for updated building codes and retrofits to mitigate potential damage.
Seafloor mapping reveals active fault zones with potential to trigger tsunamis in the central Salish Sea, affecting islands and coastal areas of the US. Researchers warn of increased tsunami risk due to recent fault activity and unstable Cascadia Subduction Zone.
Two moderate-sized earthquakes in Sichuan Province caused extensive damage and injury, likely triggered by nearby fracking operations. The earthquakes coincided with injection activities at fracking well pads, suggesting a link between the two.
A new study published in Seismological Research Letters found that California's current 100-year earthquake hiatus is highly unlikely, occurring at a 0.3% chance over the past 1000 years. The researchers analyzed long paleoseismic records and concluded that the gap isn't a statistical fluke, but rather an exceptional event.
A new study published in the Bulletin of the Seismological Society of America has revealed signs of the 1906 San Francisco earthquake in a high-resolution map of the offshore northern San Andreas Fault. The map shows two large zones of slope failure on the seafloor, indicating that the fault ruptured in multiple strands.
Researchers are using machine learning to analyze seismic data, identify earthquake centers and distinguish seismic activity from noise. Machine learning methods can also preserve analog records of past earthquakes by categorizing images.
Researchers used hourly water level records from tide gauges to detect episodic tremor and slip patterns in the Cascadia Subduction Zone. The study found that these events occurred every 14.6 months between 1996 and 2011, but not during the pre-GPS era, suggesting a potential change in the pattern over time.
A mathematical model of a train's movements during the 1906 earthquake suggests ground shaking was equivalent to at least a 'severe' level. The calculations are consistent with previous simulations and provide insights into future earthquakes in the region.
Seismic activity near Oroville Dam was related to reservoir discharge altering pressure on underlying rock fractures, causing them to open and close. The events occurred for decades prior to the dam's spillway failure and continued after it.
Researchers analyzed historical data to determine the sources of destructive Indonesian earthquakes, finding that intraslab earthquakes were responsible for many damaging quakes. The study suggests that Indonesia's 2010 and 2017 seismic hazard assessments perform well in predicting ground motion in key Javanese cities.
A study using algae deaths reveals the amount of uplift during the 2016 magnitude 7.6 Chiloé earthquake was approximately 25.8 centimeters, confirming a 3-meter maximum fault slip. This finding helps assess seismic hazards in the Chilean Subduction Zone and informs efforts to predict future major earthquakes.
A new study finds that the depth of wastewater disposal in US oil sites significantly contributes to induced seismicity. In Oklahoma, deeper disposal into the basement rock increases seismicity due to higher cumulative volume and injection rates.
A team of researchers analyzed seismic and acoustic data from US Navy explosions off the Florida coast to better understand the relationship between local magnitude and charge weight. They found that both types of data can be used to identify underwater explosions, with seismic signals providing clearer evidence.
Researchers successfully located the epicenter of the September 2017 North Korean nuclear test using regional seismic data. The study's findings confirm that subsequent seismic events were not also nuclear explosions.
Researchers identified a collapsed underground cavity and multiple small earthquakes after the September 2017 North Korean nuclear test, providing insights into the detection of nuclear explosions. The study's findings also shed light on seismic stress in the region and potential aftershocks.
Researchers in India used GPS and satellite data to track crustal deformation around reservoirs, finding that seasonal filling can reduce the strength of nearby faults and trigger earthquakes. Even small reservoirs can cause significant deformation capable of triggering an earthquake if there are critically stressed faults in the region.
A team of scientists used infrasonic microphones, seismometers, satellite, and ground camera images to calculate the Michigan bolide's time, location, height, and yield. The analysis could help assess near-Earth object threats and improve detection capabilities for clandestine nuclear tests.
Researchers map San Gabriel and San Bernardino sedimentary basins in greater detail than previous studies, revealing the San Gabriel basin is deeper and has an irregular shape. The study provides new insights into the structure of these basins, which may act as a 'waveguide' to focus energy from earthquakes.
A global collaboration, CSEP, has been studying earthquake forecast models to assess their performance and predict future seismic activity. The experiments have shed light on the predictability of earthquakes, with some models proving useful for real-time warnings during major earthquakes.