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 The East Pacific Rise (EPR) is a mid-ocean rise (usually termed an oceanic rise and not a mid-ocean ridge due to its higher rate of spreading that results in less elevation increase and more regular terrain), at a divergent tectonic plate bound ...

. It is connected to the

San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...

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 earthquake __NOTOC__ In seismology, doublet earthquakes – and more generally, multiplet earthquakes – were originally identified as multiple earthquakes with nearly identical waveforms originating from the same location. They are now characterized as dist ...

s. * 1915 Imperial Valley earthquakes: Two

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

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 The 1940 El Centro earthquake (or 1940 Imperial Valley earthquake) occurred at 21:35 Pacific Standard Time on May 18 (05:35 UTC on May 19) in the Imperial Valley in southeastern Southern California near the international border of the Unite ...

* 1979 Imperial Valley earthquake *

2010 Baja California earthquake The 2010 Baja California earthquake (also known as 2010 Easter earthquake, 2010 Sierra El Mayor earthquake, or 2010 El Mayor – Cucapah earthquake) occurred on April 4 (Easter Sunday) with a moment magnitude scale, moment magnitude of 7.2 and a ...

References

External links

Southern California Earthquake Data Center website: Imperial Fault Zone
{{- 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

Geology

Earthquake history

See also

References

Further reading

External links