
The Imperial Fault Zone is a system of
geological
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...
faults located in
Imperial County in the
Southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...
region, and adjacent
Baja California
Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...
state in Mexico. It cuts across the border between the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
.
Geology
The Imperial Fault Zone is a right lateral-moving strike-slip fault, representing the northernmost transform fault associated with the
East Pacific Rise. It is connected to the
San Andreas Fault by the
Brawley Seismic Zone. It terminates on its southern end at the
Cerro Prieto spreading center.
The Imperial Fault Zone is thought to accommodate slip from both the San Andreas and the San Jacinto fault zones. However, studies covering the last few hundred years show that the slip rate is insufficient to account for the total slip from the San Andreas system.
[Treiman, J.Jerome, compiler, 1999, Fault number 132, Imperial fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults ] The surface trace is well-located based on mapped surface offsets from historic events.
Earthquake history
The Imperial Fault Zone has a history of earthquakes of moderate magnitude, including several
doublet earthquakes.
*
1915 Imperial Valley earthquakes: Two
magnitude 6.25 shocks occurred ~1 hour apart. Six people died and several were injured in the second quake at
Mexicali
Mexicali (; ) is the capital city of the States of Mexico, Mexican state of Baja California. The city, which is the seat of the Mexicali Municipality, has a population of 689,775, according to the 2010 census, while the Calexico–Mexicali, Cale ...
, located just inside the Mexican border. Unstable banks of the New and Alamo Rivers caved in many places.
*
1940 El Centro earthquake
*
1979 Imperial Valley earthquake
*
2010 Baja California earthquake
See also
*
Cerro Prieto Fault
*
Gulf of California Rift Zone
*
Salton Trough
References
Further reading
*
*
External links
Southern California Earthquake Data Center website: Imperial Fault Zone
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Seismic faults of California
Seismic faults of Mexico
Strike-slip faults
Geology of Imperial County, California
Natural history of Baja California
Natural history of the Colorado Desert
El Centro metropolitan area
Imperial Valley
Salton Trough