Imperial Fault Zone

United States Geological Survey map with the Imperial Fault Zone outlined in red

Los Angeles

San Diego

Mexicali

Salton Sea

Tijuana

Alamo River mouth

Colorado River mouth

Laguna Salada

Yuma

Gulf of California

Colorado River Valley

Cerro Prieto volcano

Imperial fault and surrounding area. The red lines are simplified faults. Right-lateral direction of motion of the transform fault is shown (pink arrows). The red rhombs are pull-apart basins; the northern one is the site of the Niland geothermal field, the southern the Cerro Prieto geothermal field. The Imperial Fault lies in-between.

The Imperial Fault Zone is a system of geological faults located in Imperial County in the Southern California region, and adjacent Baja California state in Mexico. It cuts across the border between the United States and Mexico.

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.^[1] 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, 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

References[]

^ 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

A 300- to 550-year history of slip on the Imperial fault near the U.S.-Mexico border, Thomas and Rockwell (1996)

External links[]

Southern California Earthquake Data Center website: Imperial Fault Zone.

[1] 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

[1]

v t Seismically active fault zones and tectonic blocks of California
Statewide Faults	San Andreas Fault
Southern California	Brawley Seismic Zone Chino Fault Elsinore Fault Zone Elysian Park Fault Garlock Fault Hollywood fault Hosgri Fault Imperial Fault Zone Laguna Salada Fault Newport–Inglewood Fault Northridge Blind Thrust Fault Peninsular Ranges Puente Hills Fault Raymond Fault Rose Canyon Fault Salton Trough Salinian Block San Cayetano Fault San Felipe Fault Zone San Gabriel Fault San Jacinto Fault Zone Santa Maria River Fault Santa Ynez Fault Shoreline Fault Sierra Madre Fault Zone Ventura Fault White Wolf Fault Whittier Fault Yorba Linda Fault
Northern California	Calaveras Fault Clayton-Marsh Creek-Greenville Fault Concord Fault Hayward Fault Zone Healdsburg Fault Maacama Fault Mendocino Fracture Zone Mendocino Triple Junction Mount Diablo Thrust Fault Monta Vista Fault Pleasanton Fault San Gregorio Fault San Pablo Fault Seal Cove Fault Serra Fault Silver Creek Fault Tesla Fault West Napa Fault
Sierra Nevada	Death Valley Fault Zone Furnace Creek Fault Zone Honey Lake Fault Zone Kern Canyon Fault Maria fold and thrust belt Rescue Lineament-Bear Mountains fault zone Sierra Nevada Batholith Sierra Nevada Fault Sierra Nevada-Great Valley Block Smartville Block Walker Lane
Category California Geological Survey Seismic Hazards Mapping Act Mexico (list)

v Tectonic plates of Central America (Pacific Plate–North American Plate–Caribbean Plate Convergence Zone)
Large	Cocos Plate Nazca Plate
Small	Rivera Plate
Faults and rift zones	Atl Fault Ballenas Fault Carmen Fault Cerro Prieto Fault Guaymas Fault Gulf of California Rift Zone Farallon Fault Imperial Fault Zone Oaxaca Fault Pedro Miguel Fault Pescadero Fault Rivera Transform Fault Polochic Fault - Motagua Fault Tamayo Fault
Trenches and troughs	Alarcon Basin Carmen Basin Consag Basin Delfin Basin Guaymas Basin Middle America Trench (Acapulco/Guatemala) Tehuantepec Ridge Wagner Basin
Other	Rivera Triple Junction List of faults in Costa Rica List of seismic faults in Mexico

Imperial Fault Zone

Contents

Geology[]

Earthquake history[]

See also[]

References[]

External links[]