Ground shaking caused by the sudden release of accumulated strain by an abrupt shift of rock along a fracture in the earth or by volcanic or magmatic activity, or other sudden stress changes in the earth.
Homepage for tsunami research with links to information and images on basics, tsunamis in the Pacific Northwest, the 1998 Papua New Guinea tsunami, research on specific tsunamis, and animations in various formats.
Evansville, Indiana, is near the Wabash Valley and New Madrid seismic zones and has experienced minor damage from earthquakes in the past 200 years. This fact sheet describes three types of USGS earthquake hazard maps for Evansville and surrounding areas.
National Strong-Motion Program home page with links to program news, recent events, and datasets of digitized accelerograms downloadable as PC (*.zip) and Unix (*.tar.z) files, data processing, stations, research, publications, and personnel.
Research and monitoring to provide the Nation with a clear understanding of natural hazards and their potential threats to society, and assists with developing smart, cost-effective strategies for achieving preparedness and resilience.
Shows where current natural hazard events are occurring within the US or worldwide, with information about the geographic extent of the hazard, the US agency engaged to work on it, and how long the hazard is expected be active.
Overview of volcano hazards in California with links to monitoring data including earthquakes and deformations, long-term outlook, volcano hazards in the area, USGS response plan, image gallery, monitoring and topical studies, publications and references.