This set of resources provides seismic hazard assessments and information on design values and mitigation for the U.S. and areas around the world. Map resources include the U.S. National and Regional probabilistic ground motion map collection, which covers the 50 states, Puerto Rico, and selected countries. These maps display peak ground acceleration (PGA) values, and are used as the basis for seismic ... Full description.

This database summarizes geologic, geomorphic, and geographic information for about 2,000 Quaternary faults and folds in the United States. These structures are believed to be sources of magnitude 6 or greater earthquakes during the Quaternary Period (the past 1,600,000 years). Maps of these geologic structures are linked to detailed descriptions, including geologic setting, fault orientation, fault ... Full description.

This article describes major earthquakes that have occurred in California since the colonial era, beginning with a 1769 earthquake experienced by a Spanish expedition near what is now Los Angeles, and ending with the July 1952 earthquake in Kern County. Each account provides observer's reports of injuries, fatalities, property damage, and ground effects (cracking, subsidence). More recent earthquake ... Full description.

This map displays earthquake probabilities for several faults in the San Francisco Bay Area. The probability values are for the occurrence of one or more major (magnitude greater than or equal to 6.7) earthquakes in the San Francisco Bay Region during the next thirty years. Each fault on the map is color-coded to indicate the relative probability, and numerical values are displayed in boxes. The site ... Full description.

This interactive map displays faults for five regions in Southern California. Clicking on a region links to an enlarged relief map of the area, with local faults highlighted in colors. Users can click on individual faults to access pages with more detailed information, such as type, length, nearest communities, and a written description. In all of the maps, the segment of the San Andreas fault that ... Full description.

This guidebook contains a series of geology field trips featuring destinations along the San Andreas Fault in the region that experienced surface rupture during the Great San Francisco Earthquake of 1906. The introduction includes material on faults and earthquakes in the Bay area, a comparison of the 1906 and 1989 earthquakes, a discussion of earthquake magnitude and intensity, geologic features ... Full description.

This collection of earthquake photos, published by the United States Geological Survey (USGS), contains links to photos for specific earthquakes, as well as links to other USGS image collections and non-USGS collections. Highlights include photos from the 1906 San Francisco earthquake, the 1989 Loma Prieta earthquake, and the 1994 earthquake in Northridge, California. There is also a link to the USGS ... Full description.

This frequently-asked-questions feature deals with the relationship between earthquakes, faults, and plate tectonics; myths about earthquakes; effects and experiences; preparedness; and many other topics. Full description.

This portal provides access to a variety of resources explaining the methods used to determine the location and depth of an earthquake. The resources include the 'Travel Time Information and Calculator', an online tool that lets users choose a seismic station location and a recent earthquake, and see how long it takes different types of seismic waves to travel from the epicenter to their locations. ... Full description.

This portal provides access to information on United States Geological Survey (USGS) research and resources on tsunamis and earthquakes. Materials include news and events in USGS tsunami research, an overview of the program, and basic information on the life of a tsunami. There are also links to individual research projects. The site also features an extensive set of tsunami animations of real and ... Full description.