Greenville Fault

The Greenville Fault is a mostly right-lateral strike-slip fault. The slip rate on the Greenville Fault is poorly known but was estimated at approximately 2 mm/yr (1/12 inches/yr) by the 2003 Working Group on California Earthquake Probabilities. More recent work suggests that the rate might be as high as 4 mm/yr.

The last damaging (M5.8 and M5.4) earthquakes on the Greenville Fault occurred in January 1980 in the Livermore area. The age of the large, most recent surface rupturing earthquake on the Greenville Fault has not yet been determined.

The 1980 earthquake was a surface rupturing event, unusual for an event of that small size.

In the 2003 Working Group report, the Greenville Fault was estimated to have a maximum earthquake magnitude potential of 6.9 based on estimates of its active length. However, more recent work suggesting that the Greenville Fault connects to the Concord Fault at depth via the Diablo Thrust would allow for the Greenville Fault to rupture in larger events. In addition, the southern extent of the active Greenville Fault is poorly constrained, as is the mechanism for transfer of slip onto the fault.

The 2003 Working Group for California Earthquake Probability assigned a 3% probability that the Greenville Fault would produce a magnitude 6.7 or larger earthquake in the next 30 years.

The Greenville Fault is probably the least well understood fault in the San Francisco Bay region.