Garlock Fault
Encyclopedia
Mojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
of southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. It runs for much of its length along the southern base of the Tehachapi Mountains
Tehachapi Mountains
The Tehachapi Mountains , regionally also called The Tehachapis, are a mountain range in the Transverse Ranges system of California in the Western United States...
. It marks the northern boundary of the area known as the Mojave Block, as well as the southern ends of the Sierra Nevada and the valleys of the westernmost Basin and Range province. Stretching for 250 kilometres (155.3 mi), it is the second-longest fault in California and is one of the most prominent geological features in the southern part of the state.
The Garlock Fault runs from a junction with 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...
in the Antelope Valley, eastward to a junction with the Death Valley Fault Zone
Death Valley Fault Zone
The Death Valley Fault Zone is a right lateral-moving geologic fault in eastern California. It runs from a connection with the Furnace Creek Fault Zone in the Amargosa Valley southward to a junction with the Garlock Fault. It is considered an integral part of the Walker Lane.-References:*...
in the eastern Mojave Desert. It is named after the historic mining town of Garlock
Garlock, California
Garlock is an unincorporated community in Kern County, California. It is located east-southeast of Saltdale, at an elevation of 2169 feet .A post office operated at Garlock from 1896 to 1904 and from 1923 to 1926....
, founded in 1894 by Eugene Garlock and now a ghost town
Ghost town
A ghost town is an abandoned town or city. A town often becomes a ghost town because the economic activity that supported it has failed, or due to natural or human-caused disasters such as floods, government actions, uncontrolled lawlessness, war, or nuclear disasters...
.
Geology
The Garlock Fault is believed to have developed to accommodate the strain differential between the extensional tectonicsExtensional tectonics
Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere.-Deformation styles:...
of the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...
crust and the right lateral strike-slip faulting of the Mojave Desert
Mojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
crust.
Unlike most of the other faults in California, slip on the Garlock Fault is left-lateral; that is, the land on the other side of the fault moves to the left from the perspective of someone facing the fault. In the case of the Garlock Fault, this means that the terrain north of the fault is moving westward relative to the terrain south of the fault, which is moving relatively eastward.
Activity
The Garlock Fault moves at a rate of between 2 and 11 mm a year, with an average slip of around 7 millimeters. While most of the fault is locked, certain segments have been shown to move by aseismic creepAseismic creep
In geology, aseismic creep is measurable surface displacement along a fault in the absence of notable earthquakes.An example is along the Calaveras fault in Hollister, California. Streets crossing the fault in Hollister show significant offset and several houses sitting atop the fault are notably...
.
The Garlock is not considered to be a particularly active fault, seldom producing any shaking detectable by humans, although it has been known to generate sympathetic seismic events
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,...
when triggered by other earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
s and in one instance by the removal of ground water
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
. These events, as well as continuing microearthquake
Microearthquake
A microearthquake is a very low intensity earthquake which is usually three or less on the Richter scale. In addition to having natural tectontic causes, they may also be seen as a result of underground nuclear testing or even large detonations of conventional explosives for producing excavations...
activity and the state of the scarps
Fault scarp
A fault scarp is the topographic expression of faulting attributed to the displacement of the land surface by movement along faults. They are exhibited either by differential movement and subsequent erosion along an old inactive geologic fault , or by a movement on a recent active fault...
from previous ruptures, do indicate that the Garlock will produce another major quake at some point in the future.
The most recent notable event was a magnitude 5.7 near the town of Mojave
Mojave, California
Mojave is a census-designated place in Kern County, California, United States. Mojave is located east of Bakersfield, at an elevation of 2762 feet...
on July 11, 1992. It is thought to have been triggered by the Landers Earthquake
1992 Landers earthquake
The 1992 Landers earthquake was a magnitude 7.3 earthquake that occurred on June 28, 1992 with an epicenter near the town of Landers, California...
, just two weeks earlier.
The last significant ruptures on the Garlock were thought to be in the years 1050 A.D. and 1500 A.D.. Research has pinned the interval between significant ruptures on the Garlock as being anywhere between 200 and 3000 years depending on the segment of the fault.
Geography
The Garlock Fault constitutes one of the borders of the Mojave DesertMojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
, and is a significant geologic
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
landmark in California. Mountain range
Mountain range
A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...
s mark its western edge, and its trace is clearly visible on aerial images of the state.
Relatively few communities lie directly along the Garlock, as it is primarily situated in the desert, with Frazier Park
Frazier Park, California
Frazier Park is an unincorporated community and census-designated place in Kern County, California. Frazier Park is west of Lebec, at an elevation of 4,639 feet . It is one of the Mountain Communities of the Tejon Pass...
, Tehachapi
Tehachapi, California
Tehachapi is a city incorporated in 1909 located in the Tehachapi Mountains between Bakersfield and Mojave in Kern County, California. Tehachapi is located east-southeast of Bakersfield, at an elevation of...
, Mojave
Mojave, California
Mojave is a census-designated place in Kern County, California, United States. Mojave is located east of Bakersfield, at an elevation of 2762 feet...
, and Johannesburg
Johannesburg, California
Johannesburg is a census-designated place in Kern County, California, in a mining district of the Rand Mountains. Johannesburg is located east-northeast of Randsburg, at an elevation of 3517 feet . The terminus of the Randsburg Railway was here from 1897 to 1933. The population was 172 at the...
being the closest. However, a major rupture along the Garlock would probably be felt in most of the southern part of California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
.
Nearby Communities
- Frazier ParkFrazier Park, CaliforniaFrazier Park is an unincorporated community and census-designated place in Kern County, California. Frazier Park is west of Lebec, at an elevation of 4,639 feet . It is one of the Mountain Communities of the Tejon Pass...
- CastaicCastaic, CaliforniaCastaic, California, is an unincorporated community and census-designated place in Los Angeles County, California, north of Santa Clarita and a few miles from Six Flags Magic Mountain amusement park. It is approximately 39 miles from the downtown Los Angeles Civic Center. As of the 2010...
- CentennialCentennial, CaliforniaCentennial, California, is a proposed planned community between Bakersfield and Los Angeles in Los Angeles County located north of Highway 138, and just east of Interstate 5; specifically, surrounding the north and east sides of Quail Lake...
- TehachapiTehachapi, CaliforniaTehachapi is a city incorporated in 1909 located in the Tehachapi Mountains between Bakersfield and Mojave in Kern County, California. Tehachapi is located east-southeast of Bakersfield, at an elevation of...
- MojaveMojave, CaliforniaMojave is a census-designated place in Kern County, California, United States. Mojave is located east of Bakersfield, at an elevation of 2762 feet...
- GarlockGarlock, CaliforniaGarlock is an unincorporated community in Kern County, California. It is located east-southeast of Saltdale, at an elevation of 2169 feet .A post office operated at Garlock from 1896 to 1904 and from 1923 to 1926....
- JohannesburgJohannesburg, CaliforniaJohannesburg is a census-designated place in Kern County, California, in a mining district of the Rand Mountains. Johannesburg is located east-northeast of Randsburg, at an elevation of 3517 feet . The terminus of the Randsburg Railway was here from 1897 to 1933. The population was 172 at the...
- RandsburgRandsburg, CaliforniaRandsburg is a census-designated place in Kern County, California, United States. Randsburg is located south of Ridgecrest, at an elevation of 3504 feet . The population was 69 at the 2010 census, down from 77 at the 2000 census.-Geography:Randsburg is located at . It is on the west side of U.S...
- RidgecrestRidgecrest, CaliforniaRidgecrest, formerly known as Crumville, was incorporated as a city in 1913. It is located in the Indian Wells Valley in northeastern Kern County, California, adjacent to the Naval Air Weapons Station China Lake . Ridgecrest is the only incorporated city along US 395 in Kern County...