Gathering information through periodic or continuous measurement in the field to provide a view of current conditions. In some instances, observations may not be subject to rigorous review before release; this will be noted in the documentation accompanying the data.
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.
Information on earthquake activity, earthquake science, and earthquake hazard reduction with links to news reports, products and services, educational resources for teachers, glossary, and current U.S. earthquake activity map.
Place to provide information about ground shaking associated with significant earthquakes. A questionnaire to let us know what you felt following an earthquake in the United States or in other countries.
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.
Description of seismograms and how they are produced by drum recorders and electronic instruments with real-time seismograms for Northern California and Long Valley, California and representative seismograms for types of earthquake activity.
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.
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.