Editing Southern California (section)

====Earthquakes====
Each year, Southern California has about 10,000 earthquakes. Nearly all of them are too small to be felt. Only several hundred have been greater than [[Moment magnitude scale|magnitude]] ({{M|w}}) 3.0, and only about 15–20 have been greater than {{M|w}} 4.0.<ref>{{cite web|url=https://earthquake.usgs.gov/learning/facts.php|title=USGS facts|work=data from southern California Earthquake Center|access-date=March 18, 2009|url-status=dead|archive-url=https://web.archive.org/web/20090226130258/http://earthquake.usgs.gov/learning/facts.php|archive-date=February 26, 2009|df=mdy-all}}</ref> California as a whole enacted the [[Alquist Priolo Special Studies Zone Act]] in the wake of the [[1971 San Fernando earthquake]]. The act prohibits new construction of residential buildings closer than {{convert|50|ft|m}} from a surface rupturing active fault zone. In addition, the act improved safety by requiring new structures (both residential and commercial) to be seismically retrofitted. It also required existing infrastructure to comply.

Since 1972, numerous large magnitude earthquakes have struck Southern California with little widespread damage in part due to the act. However, exceptions can be noted for epicenters that lie directly on top of densely populated regions such as the {{M|w}} 6.7 [[1994 Northridge Earthquake]] and, to a lesser extent, the smaller {{M|w}} 5.5 [[2008 Chino Hills earthquake]]. The Northridge earthquake occurred on a blind-thrust fault directly underneath the [[San Fernando Valley]], which until the earthquake was previously undiscovered. [[Seismic retrofit]]ting of existing and new construction is aimed to prevent damage and save lives in the aftermath of a major quake, but it cannot guarantee that buildings will be unscathed if the epicenter is relatively close by.

The [[1994 Northridge earthquake]] was particularly destructive, causing a substantial number of deaths, injuries, and structural collapses. The quake caused the most property damage of any earthquake in U.S. history at an estimated $20 billion.<ref>{{cite web|title= Northridge Earthquake|year= 2005|url= http://nisee.berkeley.edu/northridge/|archive-url= https://web.archive.org/web/20060712031622/http://nisee.berkeley.edu/northridge/|url-status= dead|archive-date= July 12, 2006|access-date= December 11, 2013|df= mdy-all}}</ref>

Many Southern California [[Fault (geology)|faults]] are able to produce a {{M|w}} 6.7 earthquake or greater, such as the [[San Andreas Fault]], which can produce {{M|w}} 8.0 or greater. The largest known earthquake in California was the [[1857 Fort Tejon earthquake]] that ruptured 200+ miles (320+ kilometers) of the San Andreas Fault from [[Parkfield, California|Parkfield]] to [[Wrightwood, California|Wrightwood]]. With a recurrence interval of roughly 150 years, this part of the San Andreas fault is well within its window to produce another large earthquake. Along with the southern section of the San Andreas (in the [[Palm Springs, California|Palm Springs]] region, which has not ruptured in ~400 years), the entire Southern California portion of the San Andreas Fault is ready to produce a powerful earthquake in the near future.

Notable faults capable of large magnitude events include the [[San Jacinto Fault Zone|San Jacinto Fault]] (a splay of the San Andreas that runs directly under the I-10 & I-215 interchange), the [[Newport–Inglewood Fault|Newport–Inglewood-Rose Canyon Fault]] (located adjacent to [[SoFi Stadium]] and responsible for [[Signal Hill, California|Signal Hill]]), the [[Elsinore Fault Zone|Elsinore Fault]] (created [[Lake Elsinore]]), the [[Garlock Fault]] (which marks boundary between of the [[Sierra Nevada]] and the [[Mojave Desert]]), and the [[Hollywood fault]] (which is within feet of [[Capitol Records]] and is roughly parallel to [[Hollywood Boulevard]]).

The [[United States Geological Survey]] (USGS) has released a California earthquake forecast,<ref>{{cite web|url=http://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf|title=UCERF3: A New Earthquake Forecast for California's Complex Fault System|publisher=USGS|date=March 3, 2015|access-date=October 17, 2016|archive-url=https://web.archive.org/web/20170208032142/https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf|archive-date=February 8, 2017|url-status=live}}</ref> which models earthquake occurrence in California.

=====List of earthquakes=====
This is a partial list of earthquakes in Southern California. For a full list, see [[List of earthquakes in California]].

Note: Earthquakes with epicenters in the Los Angeles Metro Area are marked with the (#) symbol. Other earthquakes mentioned indicates shaking was felt in the region.

{{Colbegin}}
* [[1812 San Juan Capistrano earthquake]] #
* [[1812 Ventura earthquake]]
* [[1857 Fort Tejon earthquake]]
* [[1892 Laguna Salada earthquake]]
* [[1899 San Jacinto earthquake]]
* [[1918 San Jacinto earthquake]]
* [[1933 Long Beach earthquake]] #
* [[1940 El Centro earthquake]]
* [[1948 Desert Hot Springs earthquake]]
* [[1971 San Fernando earthquake]] #
* [[1979 Imperial Valley earthquake]]
* [[1968 Borrego Mountain earthquake]]
* [[1986 North Palm Springs earthquake]]
* [[1987 Superstition Hills earthquakes]]
* [[1987 Whittier Narrows earthquake]] #
* [[1991 Sierra Madre earthquake]] #
* [[1992 Big Bear earthquake]] #
* [[1992 Landers earthquake]]
* [[1994 Northridge earthquake]] #
* [[2008 Chino Hills earthquake]] #
* [[2010 Baja California earthquake]]
* [[2019 Ridgecrest earthquakes]]
{{Colend}}