Research

• Parkfield Earthquake Experiment

  USGS and the State of California are conducting a multidisciplinary, long-term project aimed at better understanding the earthquake process. The project involves recording a variety of geophysical signals before, during, and after the expected earthquake at Parkfield, testing a short-term earthquake prediction, and drilling into the San Andreas fault.

• Hayward Fault Paleoseismology

  Paleoseismologists have exhumed several faults in the San Francisco Bay region in search of their ancient earthquake (paleoseismic) histories. Learn more about paleoseismology and view photos of a trench along the Hayward Fault.

• Cone Penetration Testing

  Cone Penetration Testing (CPT) is used to infer soil type and liquefaction susceptibility in the upper hundred feet of the Earth's crust. Download USGS CPT data here.

• 3D Geologic and Seismic Velocity Model of the San Francisco Bay Region

  3D computer model of the upper 20 miles of the Earth's crust in the greater San Francisco Bay Area that will enable researchers to accurately predict the shaking levels of past and future earthquakes.

• Rupture Directions for Selected Northern California Earthquakes

  These pages show a simple inversion of peak ground motions to estimate rupture direction and rupture velocity.

• Site Response in the Northern San Francisco Bay Area, California

  This project utilizes an inversion scheme for source, site, and propagation characteristics to determine site response at seismic recording stations in the northern San Francisco Bay Area around Santa Rosa, Napa, and Sonoma.