The 2008 Wenchuan earthquake, a magnitude 7.9 rupture, resulted in over 80,000 fatalities and left four million homeless. The event showcased China's capability to demonstrate its earthquake science program to the global community.
Research reveals a causal relationship between rainfall and earthquakes, with variations in rainfall affecting pore-fluid pressure at depth and triggering earthquakes. Ground motion patterns in the Santa Clara Valley are also studied, revealing complex geological structures that influence seismic wave propagation and amplification.
Researchers identified two apparent faults cutting young deposits near Olympia, Washington, suggesting recent fault activity and potential earthquake hazards. The study utilizes marine seismic reflection data to explore shallow structures associated with inferred faults in the Tacoma and Olympia areas.
A revised seismotectonic model for the California Central Coast identifies new faults and reinterprets known ones, highlighting the need for further study to understand seismic hazards. The study also examines how large earthquakes can trigger other large earthquakes on nearby faults, a phenomenon observed in paleoseismic records.
Researchers investigate seismic activity in the Midwest US, shedding light on causes of intraplate earthquakes. The study reveals insights into stress within fault zones and the impact of glacial rebound on earthquake frequency. Key findings also highlight correlations between mantle density structures and topographic uplift.
The Seismological Society of America presents on earthquake forecasting, quantifying seismic event likelihood to provide communities with information about seismic hazards. The session also explores near-surface deformation associated with active faults and debates in earthquake science.
Researchers investigate the seismic potential of the Cascadia subduction zone, exploring temporal clustering of earthquakes and the likelihood of a next event by 2060. They also examine slow slip phenomena and landslides, shedding light on precursory patterns that may save lives.
Karen Felzer, a USGS researcher, has been recognized with the Seismological Society of America's Richter Early Career Award for her transformative and sometimes controversial research on earthquake physics. Her statistical approaches have challenged previously held theories and reshaped the way earthquakes are understood.
David Boore developed a well-known method for computing estimates of ground motion from simulated earthquakes, known as SMSIM. His work has advanced understanding of strong-motion seismology and influenced seismic building standards worldwide.
Richards' work on deep-Earth research led to a better understanding of the Earth's inner-core rotation and the detection of seismic waves. He also applied seismological methods to study nuclear weapon test explosions and their implications in politics and science.
Art Frankel led a team to update national seismic hazard maps, vastly improving public policy and building codes across the US. The new maps were used directly in building codes, enhancing earthquake safety nationwide.
This BSSA tip sheet documents the long history of earthquake monitoring by the Southern California Seismic Network (SCSN), detailing its evolving sensitivity over time. Researchers also examine the predictive capability of models to estimate ground shaking during large earthquakes in the San Francisco Bay Area.
A new study by John Anderson of the Nevada Seismological Laboratory has compiled a list of 100 earthquakes with the strongest peak accelerations (PGA) and velocities (PGV) ever recorded, exceeding thresholds of 7.31 m/s2 for acceleration and 0.65 m/s for velocity.
A recent study published in BSSA found that certain types of subduction zones exhibit lower earthquake production rates, contradicting previous assumptions. The research suggests that the efficiency of earthquake production is influenced by fault slip rate and relative plate velocity.
The October issue of BSSA features a review on strong ground motions, suggesting that the current global record reflects only a small sample of what is physically possible. Additionally, researchers explore the correlation between toppled columns and earthquake source determination in archaeoseismology.
A new study found no daily or weekly pattern to earthquakes in Western U.S. due to human activity. Seismic stations struggle to detect M>1 earthquakes, making it appear like more occur on Sundays and late at night. Researchers explored speleothem records in caves for accurate quake documentation.
A new study evaluates expected ground motion in Seattle, Victoria, and Vancouver from earthquakes of magnitude 7.5 - 9.0, providing a tool to build or retrofit structures to withstand seismic waves. Ground motions are estimated for firm ground at the three sites, with a model that engineers can adjust for local soil conditions.
The BSSA special issue on rotational seismology discusses research on rotational ground motions, including theory, instrumentation, observation, and interpretation. Rotational effects from earthquakes have been observed for centuries, but were ignored due to practical difficulties in measuring them.
Recent observations from the USArray transportable array and EarthScope instruments have shed new light on seismic wave propagation and the evolution of the Yellowstone hotspot. The analysis suggests a common mantle source for the region's unique topographic features, providing valuable insights into geological processes.
Researchers are re-evaluating earthquake potential in the Central Coast region, a high-risk area with significant population growth. Fresh data from multiple datasets will focus on faults including the Hosgri Fault Zone and highlight newly identified features such as a linear trend of seismicity and magnetic anomalies.
A giant Cascadian earthquake could cause severe damage and possible collapse in Seattle's high-rise buildings, particularly those constructed before 1994 building code changes. The Seattle basin amplifies long-period motions, making tall steel buildings susceptible to low-frequency shaking.
The 1989 Loma Prieta earthquake had a profound societal impact, transforming earthquake sciences and engineering. The event led to improved understanding of earthquake processes and triggered major changes in building codes and disaster response.
A massive earthquake swarm in Yellowstone National Park was analyzed by SSA researchers, revealing epicenter migration and sudden depth changes. The study suggests that hydrothermal fluids may be responsible for the swarm's source properties.
Researchers linked pre-historic seismic events on the San Andreas Fault to assess likelihood of future great ruptures. Analysis suggests several events similar to a historical earthquake occurred since A.D. 900 on the southern San Andreas fault.
Archuleta's research challenged long-held beliefs and prompted new research, leading to a better understanding of earthquake physics and hazards. He has also made significant contributions as a leader in the seismological community, including serving as president of the Seismological Society of America.
David Wald's work has advanced seismic data analysis, enabling efficient dissemination of earthquake information to first responders and the public. His programs, such as ShakeMap and 'Did You Feel It?', have become invaluable tools in humanitarian disasters.
Miaki Ishii has made two groundbreaking discoveries in geophysics that have fostered intense debate and subsequent research on deep Earth seismology. Her work challenged the long-held theory of a homogenized mantle, revealing lateral variations in mantle density instead.
Scientists investigated early warning system accuracy, finding it unlikely to estimate large earthquakes with high precision. Rapid magnitude estimation works better when using multiple seismic stations in close proximity to the fault.
Researchers have discovered an abundance of pseudotachylytes, rocks formed under extreme heat and friction during earthquakes, in the Sierra Nevada. This finding reveals the importance of heat generated by the earthquake process and challenges previous assumptions about their rarity.
Probabilistic maps detail degree of hazard within broader zones, providing perspective on actual risk to users. Liquefaction probability is highest in some areas along major creeks with a water table close to the surface.
Researchers Jan Schmedes and Ralph J. Archuleta found that locally ground motion increases near the epicenter but not equally along the rupture plane of large earthquakes. A new method for estimating detection capability was also developed, providing a more complete picture of seismicity.
A linear string of mud pots and volcanoes indicates a surface evidence for the southern extension of the San Andreas Fault. Researchers identified 33 geothermal features forming a clear pattern, revealing a planar rift extending to considerable depth in the crust.
Numerical earthquake models are providing a means to understand physical processes and predict earthquakes, reducing damage and loss of life. Simulations show that surface-rupturing earthquakes absorb more seismic energy than buried ones, resulting in less ground shaking.
Researchers have discovered that tiny earth tremors caused by wind-driven ocean waves can track extreme storms. Microseism signals show up as oscillations of Earth's surface and increase in amplitude with storm intensity, offering a unique way to monitor storm intensities across seasons and geographical locations.
Researchers have compared historical monitoring data with actual records from the test site to refine nuclear explosion detection methods. The study reveals that today's techniques can detect nuclear tests with high accuracy, thanks to improved monitoring experience gained from past efforts.
Researchers at the SSA meeting will discuss the Rio Grande Rift, a region prone to earthquakes, and its potential connection to ancient volcanic activity. The study also explores seismic hazard estimates for areas like New Madrid and Charleston, which may be underreported.
Researchers are joining forces to study past earthquakes in the archaeological record, which can provide valuable insights into seismic hazard estimates. A new standardized method, known as the Archeological Quality Factor (AQF), is being proposed to document the certainty of ancient earthquake records.
A study suggests seismic hazard maps for New Madrid and Charleston zones may be less dire than current predictions, as a new model assumes earthquakes are less likely to occur immediately after a major quake. The 'time-dependent' model sheds light on assumptions in hazard mapping, which affect building codes and preparations.
Researchers have found a potential link between seismic activity on the southern Cascadia Subduction fault and major earthquakes along the northern San Andreas Fault. The study suggests that Cascadia earthquakes may trigger San Andreas earthquakes, with an average recurrence rate of approximately 220 years for both faults.
Researchers understand that a smooth decrease in stress at the end of a primary fault reduces the likelihood of an earthquake jumping to another fault. This study highlights the importance of slip gradient and rupture front acceleration in determining fault jump probability.
New research at Yucca Mountain, Nevada, limits potential ground movement to 3.6 meters per second, reducing earthquake risk. Small earthquakes may serve as predictors for large ones, contradicting conventional seismology theories.
Researchers identify correlation between 3D basin geometry and observed shaking in previous earthquakes, leading to improved construction and seismic hazard assessments. A new tool for evaluating site conditions is also proposed, which could aid in risk assessment for earthquake-prone regions worldwide.
Researchers at University of Oregon and US Geological Survey identified past activity clues for the Southern San Andreas Fault, ranking 316 event indicators. They also improved the accuracy of physics-based predictive earthquake simulations, enabling safer building designs.
Scientists developed a new technique to discriminate between small earthquakes and mine blasts, achieving a success rate of 97%. Researchers also created the most detailed 3D model of the Hayward Fault System in Northern California, revealing that it poses the greatest risk for major quakes in the next 30 years.
The Seismological Society of America honors MIT's M. Nafi Toksoz for his 40-year investment in the field, defining seismology and its practice. He has mentored over 100 postdoctoral students, promoting a research environment at MIT.
A recent study found that media accounts of past earthquakes, such as the M7.6 Bhuj, India earthquake of 2001, can be misleading due to a natural bias towards dramatic effects. The research compared written accounts with ground-based surveys and concluded that the media bias can be significant, particularly at stronger shaking levels.
A recent study highlights the urgent need to update design standards in stable continental regions like Peninsular India. The assessment shows that major urban areas are underprepared for earthquakes, with risks exceeding current safety standards.
The January special issue of BSSA focuses on the 2004 Sumatra earthquake, which is the best recorded large earthquake in history. The study reveals that great earthquakes can occur in various types of subduction zones, not just fast and young ones.