The Elsinore Fault Zone is a large, right-lateral strike-slip geological fault structure in

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 ...

. The fault is part of the trilateral split of 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 ...

system and is one of the largest, though quietest, faults in Southern California.

Fault characteristics

The Elsinore Fault Zone, not including Whittier, Chino, and Laguna Salada faults, is long with a slip-rate of 4.0 millimeters/year (0.15 in/yr). It is estimated that this zone is capable of producing a quake of 6.5–7.5 M_W. The projected interval between major rupture events is 250 years. The last major rupture event on the main Elsinore fault was in 1910 with a 6 M_W earthquake centered just northwest of the city of Lake Elsinore.

Fault segments and geography

The fault runs from the mountainous Peninsular Ranges region between El Centro and

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

, northwest to the Chino Hills range and Chino Hills. On the southern end of the fault zone is the southeastern extension of the Elsinore fault zone, the Laguna Salada Fault. At its northern end, the Elsinore Fault Zone splits into two segments, the Chino Fault and the Whittier Fault. In the Elsinore Trough, the Elsinore Fault Zone creates four

graben In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

rift valleys between the Santa Ana Mountain Block and the Perris Block: the Temescal Valley, Elsinore Valley with its large sag pond of Lake Elsinore, the

Temecula Valley The Temecula Valley (Spanish language, Spanish: ''Valle de Temecula'') is a graben rift valley in western Riverside County, California. The Temecula Valley is one of the graben valleys making up the Elsinore Trough, created by the Elsinore Fau ...

, and Wolf Valley. In the Elsinore Trough, the fault zone is split into pairs of parallel strands with the Glen Ivy North Fault and Lee Lake Fault forming the first valley, the Glen Ivy South Fault and Willard Faults the second, and the Willard and Wildomar Faults the last two valleys to the southeast. A multi-year study published in 2018 suggests a connection between the Elsinore fault and other fault lines farther south, in Mexico: "...observations of the Yuha Desert and Salton Trough suggest that the 2010 M7.2 El Mayor – Cucapah earthquake rupture, the Laguna Salada fault in Baja California, Mexico, and the Elsinore fault in California are part of the same fault system."

References

External links

M6.5 Earthquake on the Elsinore Fault (Santa Ana)
– Southern California Earthquake Center {{Clear * Seismic faults of California Strike-slip faults Geology of Los Angeles County, California Geology of Orange County, California Geology of Riverside County, California Geology of San Bernardino County, California Geology of San Diego County, California Inland Empire Natural history of Los Angeles County, California Natural history of Orange County, California Natural history of Riverside County, California Natural history of San Bernardino County, California Peninsular Ranges

Fault characteristics

Fault segments and geography

References

Further reading

External links