Bay Area Velocity Unification

GPS velocities in the San Francisco Bay Area relative to site LUTZ on the Bay Block. Note the right lateral deformation and deformation gradient across the plate boundary that results from locked faults in the Bay Area.

Project Summary What is the rate of strain accumulation on faults in the San Francisco Bay Area? We have compiled the most up-to-date velocity field for the Bay Area and use 3-D elastic models to determine the slip rates on Bay Area faults most consistent with our data. The project includes abundant field work collecting campaign style GPS data in urban and suburban settings. We combine our own data with all known geodetic grade GPS data collected over the last decade by six different agencies. When combined using a uniform methodology, we call this new data set "BAVU" (pronounced "Bay View", or the Bay Area Velocity Unification). We then use simple numerical models to interpret the surface deformation data in terms of locking and slip along faults at depth. Our results are important for direct input into statistical models of regional seismic hazard.

For data, time series and maps go to the BAVU Web Site

Tools Trimble 5700 GPS Receivers, 4-wheel drive vehicle
GAMIT/GLOBK data processing software

Geographic Location Northern California from Sacramento to San Luis Obispo

Group Members Involved Matthew d'Alessio <Email> <Personal Web Site>
Ingrid Johanson <Email> <Personal Web Site>
Dennise Templeton <Email> <Personal Web Site>
Frederique Rolandone, Roland Bürgmann

Project Duration 1994-2003, with work ongoing as of 2004

More Information < BAVU Web Site>