Earthquake Hazards

Crustal Deformation Monitoring

Geodetic methods are used to measure movement of the Earth’s surface and strain in the upper few hundred meters of the Earth’s crust.

These data record subtle fault-related deformation of the Earth’s crust that does not generate seismic waves as well as the rapid motion that occurs during earthquakes. Geodetic measurements have applications for seismic hazard assessment, earthquake early warning, earthquake likelihood monitoring, and research into underlying physical processes

Geodetic Data

Legacy Networks

  • Two-color Electronic Distance Meter (EDM)

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

  • Geodolite Data

    Measurements of the distance between pairs of benchmarks in surveying networks located in the central and western U.S. and Alaska. Data were collected between 1959 and 1993.

Region-specific Monitoring

  • 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.

  • San Francisco Bay Area

    This page examines GPS along with creepmeter and strainmeter data that monitor deformation across the SF Bay region.