Seismo Lab Logo

Magnitude 4 earthquakes near Ukiah, CA

Information from UCB & USGS Menlo Park
Date & Time (Local): 2001/12/07
06:29:09 (PDT)
01:41:05 (PDT)
Date & Time (UTC): 2001/12/07
14:29:09 (UTC)
09:41:05 (UTC)
Location: 14 km (9 miles) SSE of Ukiah, CA
39.042, -123.115
14 km (9 miles) SSE of Ukiah, CA
39.045, -123.120
Depth (km): 6.9 6.9
ML: 4.1 4.1
MW (preferred): 4.3 4.4
Fault Zone: Maacama

The Ukiah area recently experienced two M4.0+ events. The first, which occurred on December 7, had a local magnitude (ML) of 4.1 and moment magnitude (Mw) of 4.3. The December 14 event was located just northwest of the December 7th earthquake, both of which occurred along the Maacama Fault Zone. This fault zone is thought to slip at a rate of about 9mm/year, similar to the slip rate along the Rodgers Creek and Hayward Fault Zones that continue to the south.

More information about the earthquake potential of the Maacama Fault and other faults in this region can be found in a 1996 USGS report on Northern California Earthquake Potential, particularly in the section on North Coast faults.

  • Details

  • Maps

  • Seismograms

  • Ground shaking information

    Return to the Events of Interest
    Return to the Berkeley Seismological Laboratory

    Berkeley Seismological Laboratory, 202 McCone Hall, UC Berkeley, Berkeley CA 94720-4760
    Questions or comments? Send e-mail:
    © 2001, The Regents of the University of California.