Historic Earthquakes

Santa Rosa, Sonoma County, California
1969 October 02 04:46 and 06:19 UTC (local October 1)
Magnitude 5.6 and 5.7

These earthquakes caused one fatality and left severe property damage in Santa Rosa; several old brick and wood-frame buildings were damaged beyond repair; chimneys were destroyed; sidewalks buckled; and underground pipes ruptured. Other buildings in Santa Rosa that sustained substantial damage included Fremont Elementary School, Sonoma County Social Service Building, J.C. Penney Company store, and Veterans Memorial Building. Total damage was estimated at $8.35 million.

Significant cracking or offset of roads was not observed, except for some settlement of fill at one freeway overpass. On the north side of Santa Rosa, about 36 transverse fractures were observed in the asphalt of Poppy Drive; and fresh, irregular cracks formed in the dry dirt roads in the Rural Cemetery near Poppy Drive. Many tombstones in cemeteries were thrown down or twisted. Both earthquakes were felt over a moderate area of west-central California from Sonoma County east to Sacramento County and south to Santa Cruz County. Several aftershocks were felt in the Santa Rosa area.

Abridged from Seismicity of the United States, 1568-1989 (Revised), by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, Washington: 1993.