Historic Earthquakes

Off the coast of Humboldt County, California
1980 Nov 08 10:27:34.0 UTC
Magnitude 7.2

A major earthquake, the largest in this area in 24 years, injured six people and caused property damage estimated at $2 million. Most of the damage occurred east of Fields Landing, where two sections of an overpass on U.S. Highway 101 collapsed onto the railroad tracks below. At Fields Landing, two houses were displaced from their foundations, one unreinforced chimney fell, and gas, water and sewer lines were broken. This shock and most of its aftershocks occurred on a large, left-lateral, strike-slip fault that strikes about N. 50 deg. E. from the Mendocino Fracture Zone. Felt over a large area, including parts of Oregon, western Nevada, and northern California--from Eugene, Oreg., south to the San Francisco bay area and from the coast east to Fallon, Nevada. Many aftershocks occurred.

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.