The Hosgri Fault is an offshore fault zone located near the Central Coast of California

Central Coast of California

The Central Coast is an area of California, United States, roughly spanning the area between the Monterey Bay and Point Conception. It extends through Santa Cruz County, San Benito County, Monterey County, San Luis Obispo County, and Santa Barbara County...

 in San Luis Obispo County

San Luis Obispo County, California

San Luis Obispo County is a county located along the Pacific Ocean in the Central Coast of the U.S. state of California, between Los Angeles and the San Francisco Bay Area. As of the 2010 census its population was 269,637, up from 246,681 at the 2000 census...

. The main fault stretches for about 140 kilometres (87 mi), and the coastal communities closest to it are Cambria

Cambria, California

Cambria is a seaside village located midway between San Francisco and Los Angeles on the California State Route 1 . The name Cambria was settled upon in 1869 .It is a census-designated place in San Luis Obispo County, California, United States...

, San Simeon

San Simeon, California

San Simeon is a census-designated place on the Pacific coast of San Luis Obispo County, California. Its position along State Route 1 is approximately halfway between Los Angeles and San Francisco, each of those cities being roughly 230 mi away...

 and Morro Bay

Morro Bay, California

Morro Bay is a waterfront city in San Luis Obispo County, California, United States. As of the 2010 census, the city population was 10,234, down from 10,350 at the 2000 census.- History :...

, Baywood Park-Los Osos

Baywood-Los Osos, California

Baywood-Los Osos is an unincorporated area located in western San Luis Obispo County, California, U.S., near the city of San Luis Obispo. The population was 14,351 at the 2000 census...

, and Avila Beach

Avila Beach, California

Avila Beach , pronounced AH-vuh-luh, is a census-designated place in San Luis Obispo County, California, USA and located about 160 miles northwest of Los Angeles, and about 200 miles south of San Francisco. The ZIP Code is 93424. The community is inside area code 805...

. The fault system (including branches) is some 420 km long, and is a right-lateral strand of the San Andreas fault system.

Fault Information

The Hosgri Fault is a component of the San Andreas Fault

San Andreas Fault

The San Andreas Fault is a continental strike-slip fault that runs a length of roughly through California in the United States. The fault's motion is right-lateral strike-slip...

 system. Its movement is primarily reverse thrust

Thrust fault

A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...

, as well as exhibiting right lateral slip, and is thought to be capable of generating earthquakes of up to magnitude 7.5. The November 4, 1927 Lompoc earthquake (magnitude 7.1) is thought to have occurred on this fault.

Seismologists

Seismology

Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...

 monitor activity on the Hosgri fault constantly because of its physical proximity to the nuclear Diablo Canyon Power Plant

Diablo Canyon Power Plant

Diablo Canyon Power Plant is an electricity-generating nuclear power plant at Avila Beach in San Luis Obispo County, California. The plant has two Westinghouse-designed 4-loop pressurized-water nuclear reactors operated by Pacific Gas & Electric. The facility is located on about in Avila Beach,...

. In fact, the fault lies only 2½ miles offshore from the nuclear power plant

Nuclear power plant

A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...

. More recently in 2008, yet another even closer fault was discovered, the Shoreline Fault

Shoreline Fault

Shoreline Fault is a 25 km long vertical strike-slip fault discovered in 2008 that lies less than a mile from the Diablo Canyon Nuclear Power Plant in California...

1 mile from the NPP.