Historic Earthquakes

Chalfant Valley, California
1986 July 21 14:42 UTC
Magnitude 6.2

Known as the Chalfant Valley earthquake, this shock injured two people and caused an estimated $2.7 million damage to property in the Bishop-Chalfant area. At Bishop, a few chimneys cracked, windows broke, ceiling tile and plaster fell, and exterior walls cracked in several buildings. The brick facade on a bank on Main Street also sustained cracks. Most of the damage at Chalfant was due to mobile homes being shaken off their supports, which damaged water and gas lines. Fractures in the ground were observed in the White Mountains frontal fault zone. Many small landslides and spectacular rockfalls occurred in the epicentral area.

The shock was felt mainly in California and western Nevada but was reported in multistory buildings as far distant as Salt Lake City, Utah. A foreshock occurred on July 20 at 14:29 UTC, and an aftershock occurred on July 31 at 07:22 UTC. Thousands of smaller aftershocks occurred through September 30, 1986.

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.