Latest Seismic hazard Stories
Engineers and city planners study surface geology in order to construct buildings that can respond safely to earthquakes. Soft soil amplifies seismic waves, resulting in stronger ground motion than for sites built over bedrock. This study examines the local site response for the city of Ottawa, and the results indicate seismic waves may amplify ground motion greater than expected or referenced in the National Building Code of Canada. Current knowledge of the earthquake activity in Ottawa...
redOrbit Staff & Wire Reports - Your Universe Online The most dangerous fault line on the island of New Zealand is the Alpine Fault. It is approximately 80 miles northwest of the islands main city of Christchurch. Research published in the prestigious journal Science, co-authored by University of Nevada, Reno's Glenn Biasi and colleagues at GNS Science in New Zealand, shows that very large earthquakes have been occurring regularly on the Alpine Fault along the southwest coastline of...
Global seismic hazard maps exist to help societies and decision-makers anticipate and prepare for earthquakes. These maps are supposed to depict the maximum level of ground shaking likely to be produced by an earthquake in a given area. In the past decade, however, ground motions and death tolls in areas struck by earthquakes have far exceeded these maps' projections. Thus, scientists are calling into question the standard methods used to estimate seismic risk, and accepted assumptions and...
Results of a new U.S. Geological Survey study conclude that faults west of Lake Tahoe, Calif., referred to as the Tahoe-Sierra frontal fault zone, pose a substantial increase in the seismic hazard assessment for the Lake Tahoe region of California and Nevada, and could potentially generate earthquakes with magnitudes ranging from 6.3 to 6.9. A close association of landslide deposits and active faults also suggests that there is an earthquake-induced landslide hazard along the steep...
New dynamic computer model first to show full history of a fault segment For those who study earthquakes, one major challenge has been trying to understand all the physics of a fault—both during an earthquake and at times of "rest"—in order to know more about how a particular region may behave in the future. Now, researchers at the California Institute of Technology (Caltech) have developed the first computer model of an earthquake-producing fault segment that reproduces, in a single...
Things could get shaky as scientists will gather in San Diego next week to present their latest seismological research at the annual conference of the Seismological Society of America (SSA). This year’s conference is expected to have record numbers, as well as a special public town hall meeting which will feature talks on the seismic dangers in San Diego as well as the threat of future earthquakes and tsunamis. As the city of San Diego sits on top of a fault system, there is a...
A new study evaluates the seismic hazards for the entire Central America, including specific assessments for six capital cities, with the greatest hazard expected for Guatemala City and San Salvador, followed by Managua and San José, and notably lower in Tegucigalpa and Panamá City. The study, published in the April issue of the Bulletin of the Seismological Society of America (BSSA), included input from seismic hazard experts from Costa Rica, Guatemala, Honduras, Nicaragua, El Salvador,...
Seismology tip sheet: New Madrid seismic zone, Japan quake, earthquake triggering and more among topics to be discussedThis tip sheet highlights presentations at the upcoming international meeting of SSA, which is an international scientific society devoted to the advancement of seismology and its applications in understanding and mitigating earthquake hazards and in imaging the structure of the Earth.These summaries reflect submitted abstracts and the actual presentations will include...
A new National Research Council report presents a 20-year road map for increasing U.S. resilience to earthquakes, including a major earthquake that could strike a highly populated area. The report was mostly written prior to the March 11 earthquake in Japan, but the committee of experts who authored it noted that the Japanese experience is a reminder of the devastation that can occur even in a country acknowledged as a leader in implementing earthquake-resilience measures.In recent decades,...
The Christchurch, New Zealand earthquake that took place on February 22 has been illustrated in new radar imagery. The magnitude 6.3 tremor killed over 160 people and shattered a city reeling from a previous seismic event in September. Data downloaded from the Japanese Alos spacecraft mapped the way the ground deformed during the most recent quake. It shows clearly that the focus of the tremor was right under the city's south-eastern suburbs. The type of image is known as a synthetic aperture...
