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
-
Daily and Near Real-time Global Positioning System (GPS) Data
Velocities, time series, and maps for stations observed with GPS in the western U.S.
-
Real-time GPS Data
High-rate GPS networks in the San Francisco Bay Area and Long Valley.
-
Fault Creep, Borehole Strain, and Tiltmeter Monitoring Measurements
Interactive maps and near real-time data from creepmeters, strainmeters, tiltmeters and other geophysical instruments.
-
Alinement Array Data
Creep rate measurements on San Francisco Bay Region faults updated annually. The San Francisco State University Creep Project discusses fault creep in depth.
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.