Earthquakes

The 1989 Loma Prieta earthquake ended decades of tranquility in the San Francisco Bay region. It was a wakeup call to prepare for the potentially even more devastating shocks that are inevitable in the future. Since 1989, the work of the U.S. Geological Survey and other organizations has improved understanding of the seismic threat in the Bay region, promoted awareness of earthquake hazards, and...

Post-earthquake scientific and engineering investigations are undertaken by the USGS and its partners to capture critical information to understand the causes and impacts of the event, lessons from which can substantially improve the Nation’s resilience after future earthquakes.

The M6.0 South Napa, California Earthquake was the largest earthquake to strike the San Francisco Bay Area in over 25 years. It caused significant damage to over 100 structures and was widely felt across the region.

Three different earthquake scenarios are presented to show the estimate of shaking levels for a M7.8 earthquake on the San Andreas Fault, a M6.7 on the Hayward Fault, and a M6.9 on the Calaveras Fault.

This map shows the liquefaction hazard in the communities of Alameda, Berkeley, Emeryville, Oakland, and Piedmont for a magnitude 7.1 earthquake on the Hayward fault.

These maps are designed to give the general public as well as land-use planners, utilities and lifeline owners, and emergency response officials, new and better tools to assess their risk from earthquake damage. The maps also contribute to the California Geological Survey’s Seismic Hazard Zone maps.

On February 7th, 2012, the U.S. Geological Survey and local and regional partners unveiled a new series of seismic hazard maps that outline the effects from quakes occurring in the Evansville area.

The goals of USGS earthquake geology and paleoseismology research are 1) to make primary observations and develop ideas to improve our understanding of the geologic expression of active faulting, and 2) to acquire data that will improve the National Seismic Hazard Model. Geological research allows us to characterize faults, including the identification of secondary seismogenic structures, to study...

The overarching theme of this project is to discover as much as we can about earthquakes and faulting from field and laboratory observations and to combine this with geophysical, geological, geochemical, and mathematical (including computational) modeling of earthquake sources and fault zones so as to best improve probabilistic USGS Earthquake Hazard Assessments. This project also investigates...

The overall objective of this research is to improve the understanding of the damaging ground motions produced in earthquakes in order to develop better methods for seismic hazard assessment and mitigation in urban areas. The overall objective of this research is to improve the understanding of the damaging ground motions produced in earthquakes in order to develop better methods for seismic...

Southern California has the highest level of earthquake risk in the United States, with half of the expected financial losses from earthquakes in the Nation expected to occur in southern California. Sitting astride the Pacific - North American plate boundary at the Big Bend of the San Andreas Fault, Southern California has over 300 faults capable of producing magnitude 6 and larger earthquakes...

At the USGS Astrogeology Science Center we conduct research on Planetary Defense. Planetary Defense involves predicting potential impactors (asteroids, comets), and studying how to deflect or divert them, as well as the potential effects of an impact. Effects include short-term effects such as blast damage, but also long-term effects such as climate and social impacts.