CISN label
CGS | USGS | Caltech | CalEMA | UCB

Earthquake Probability Report (2003)

A new study assessing the probability of earthquakes in the San Francisco Bay Area was released today (4/22/2003) by Working Group 2002.

This is the latest in an on-going effort to quantify earthquake hazards in the San Francisco Bay Area. Led by the USGS, the working group consists of scientists from the USGS, California Geological Survey, major universities, and private companies. Previous studies were released in 1988, 1990 (reflecting changes following the 1989 Loma Prieta earthquake), and 1999.

The recently released study accounts for both changes in the understanding of earthquake science - ideas on how faults interact and new or revised information about historical earthquakes and the rate of strain acculmulation - as well as new ideas about modeling.

The results indicate the Bay Area is highly likely to experience a damaging earthquake - a 62% probability for one or more events of M6.7 or higher from 2003 to 2032. The Hayward-Rodgers Creek system is estimated to have a probability of 27% - the highest of the Bay Area faults.

Also as part of this study, scenario earthquakes - representing events on faults that have ruptured in the past or have a likelihood of rupturing in the future - were constructed. Maps predicting ground shaking for these events are available.

California Integrated Seismic Network

CGS USGS OES Caltech UC Berkeley