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.
Study of the probability of a major earthquake in San Francisco Bay region with colored map and links to relevant publications. Text also available in PDF format and graphic available in Illustrator or Photoshop format.
Describes the monitoring effort and provides real-time data of the current restless activity of the caldera, including earthquakes, ground deformation, and release of volcanic gas and plus link to volcano monitoring techniques.
Information on world earthquake activity with links to facts and lists on large earthquakes, earthquake e-mail notification, hazards and preparedness, educational links, news and highlights and other seismic information.
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.