Earthquakes

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.

“The Landers earthquake, which had a moment magnitude (Mw) of 7.3, was the largest earthquake to strike the contiguous United States in 40 years. This earthquake resulted from the rupture of five major and many minor right-lateral faults near the southern end of the eastern California shear zone.” —Kerry Sieh et al., Science, v 260, issue 5105, 171-176.

The USGS periodically updates its National Seismic Hazard Models (NSHMs) for the United States and its territories. For each NSHM update, the USGS requests that the seismic hazard community bring to our attention new earthquake source and ground motion data or models that could be included. The deadlines for these community contributions, and the schedule for each NSHM update (including public...

USGS is actively pursuing research in earthquake early warning.