The 1980 Livermore earthquake occurred on January 24 at 11:00 PST in California. The epicenter of the 5.8 earthquake was a hilly area southeast of
Mount Diablo
Mount Diablo is a mountain of the Diablo Range, in Contra Costa County, California, Contra Costa County of the eastern San Francisco Bay Area in Northern California. It is south of Clayton, California, Clayton and northeast of Danville, Califo ...
and north of
Livermore Valley. The earthquake had a maximum
Modified Mercalli intensity
The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...
of VII (''Very strong''). Forty four people were injured and damage across the San Francisco Bay Area totaled $11.5 million, with the majority inflicted at the
Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...
.
Earthquake
The
mainshock
In seismology, the mainshock is the largest earthquake in a sequence, sometimes preceded by one or more foreshocks, and almost always followed by many aftershocks.
Foreshock
A foreshock is an earthquake that occurs before a larger seismic eve ...
was preceded by a 2.7
foreshock
A foreshock is an earthquake that occurs before a larger seismic event (the mainshock) and is related to it in both time and space. The designation of an earthquake as ''foreshock'', ''mainshock'' or aftershock is only possible after the full sequ ...
1.5 minutes prior. In the first six says after the mainshock, 59 aftershocks were recorded measuring ≥ 2.5 .
On January 26, a 5.3 aftershock occurred with an epicenter southeast of the mainshock. Six hundred aftershocks were recorded in the 33 days after the mainshock. An analysis of
P wave indicate the
fault plane solution
The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is ...
was right-lateral strike-slip faulting.
Faulting
Surface faulting consisting of discontinued and small offsets occurred along the Greenville and Las Positas faults. At least of rupture occurred on the Greenville Fault, but it may have extended south to Interstate Highway 580, giving a possible total length of . Surface faulting was sparse along the rupture. A maximum right-lateral offset of and vertical offset of was recorded. A rupture was located east of the main rupture, and away from another known fault. The secondary break produced of right-lateral offset, and of extension. Offset was also recorded along at least of the Las Positas Fault Zone. These consisted of small left-lateral offsets.
Damage
Damage to property was nonstructural—consisting of fallen ceiling tiles, detached bricks from chimneys, ruptured gas and water lines, shattered windows, and mobile homes displaced from their foundations. At a ranch north of Livermore, along Vasco Road, two brick-and-stone fireplaces were fractured and offset from their walls. Along Interstate 580 and Greenville Road, a concrete pavement sunk , and the a concrete abutment fractured and spalled. Forty four people were injured. Damage at the
Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...
was estimated at $10 million.
The January 26 aftershock caused six additional injuries in Livermore from glass and falling debris. Fifty homes sustained minor damage in
Tassajara. A fireplace was damaged, walls and concrete fractured, walls detached from ceilings, windows broke and a chimney collapsed. In
Danville, a brick chimney and fireplace were damaged, stone wall was destroyed, and walls, patios, sidewalks and ceilings cracked. Several other towns reported slight damage.
See also
*
List of earthquakes in 1980
*
List of earthquakes in California
The earliest known California earthquake was documented in 1769 by the Spanish explorers and Catholic missionaries of the Portolá expedition as they traveled northward from San Diego along the Santa Ana River near the present site of Los Angeles ...
References
{{earthquakes in California
1980 earthquakes
Earthquakes in California
1980 in California
History of the San Francisco Bay Area
January 1980 events in the United States