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.
Post-earthquake map derived from 1:24,000-scale base maps incorporating high- and medium-resolution remotely sensed imagery following the 7.0 magnitude earthquake near the capital city of Port au Prince, Haiti, on January 12, 2010
Post-earthquake map derived from 1:24,000-scale base maps incorporating high- and medium-resolution remotely sensed imagery following the 7.0 magnitude earthquake near the capital city of Port au Prince, Haiti, on January 12, 2010
Description of intensity and magnitude as indicators of the size of an earthquake and the levels of severity measured on the Richter Magnitude Scale and the Modified Mercalli Intensity Scale.
Preparing for earthquakes along this important fault requires studying the history of its movement and its geology, as well as understanding how society has built the area around it.
Fact sheet describing plans for a San Andreas Fault Observatory at Depth (SAFOD) by drilling into the fault to install instruments for long-term monitoring near the location of the magnitude 6 Parkfield earthquakes.
Online booklet on the San Andreas fault system on the California coastal region with discussion of faults, relationship of faults and earthquakes, magnitude of earthquakes, and earthquake probability.
The Ocean Bottom Seismometer facility provides technical support for a variety of scientific investigations ranging from deep crustal structure to gas hydrate and surface sediments.
Annotated list of resources about the great earthquake of 1906, which caused significant devastation in and around San Francisco, California, compiled for the 100th anniversary of the disaster.