Crustal Deformation

As a consequence of continental plate movement, the Earth's surface near active faults deforms before, during and after earthquakes. Similarly, the ground surface near active volcanoes also deforms as a consequence of eruptions and volcano evolution. Crustal deformation can be observed as relative movement of points on the Earth's surface, ground tilt, ground strain, and fault slip (creep). We routinely measure these and other parameters that reflect this deformation.

• Earthquake & Volcano Stress Triggering

  Geodetic modeling using GPS and InSAR. Earthquake stress triggering and stress transfer analyses.

• Geodolite Results

  Two files are accessible: One contains approximate positions for all the stations. The other contains the observed line lengths.

• Global Positioning System (GPS) Observations

  Velocities, time series, and maps for stations observed with GPS.

• Long Valley

  Long Valley, in eastern California, is the center of continuing volcanic activity and moderate earthquakes. Links to instrumental monitoring of geophysical activity in the area.

• Modeling the Tectonic Deformation of Western North America through Time

  Quicktime animations showing the faulting history of the western United States and northwestern Mexico from 30 million years ago to the present.

• Parkfield Experiment

  Located on the San Andreas fault about halfway between San Francisco and Los Angeles, Parkfield CA has experienced 6 moderate earthquake (M=5 to 6) since 1857. Links to measurements which should provide more information about the causes and the effects of earthquakes.

• Real-time Fault Monitoring Data

  Interactive maps and near real-time data from creep-meters, strain-meters, tilt-meters, water level recorders and other geophysical instruments.

• SF State University Creep Project

  Creep measurements are taken every 2-3 months along active strike-slip faults in the San Francisco Bay region.

• Two-color Electronic Distance Meter (EDM)

  Results from measuring changes in distances using a two-color EDM. Measurements are made in Parkfield, Long Valley, and Southern California.