Sunday, April 4, 2010

Earthquake history

California is overdue for a big one. A really big one. The end of the San Andreas fault was not experienced a major rupture for at least 250 years. The San Andreas fault runs for roughly 1287km (800 miles) through western and southern California in the US. It marks the meeting point of the Pacific and North American tectonic plates. The two plates either side of the San Andreas fault are moving past each other at a rate of about 25mm each year - the fault's "slip rate." If all the strain was released at once, it would have enough energy to unleash a magnitude-8 earthquake - roughly the size of the devastating 1906 quake in San Francisco. Quakes are predicted to occur on the southern part of the fault every 200-300 years.

Duck, cover and hold.


July 29, 2008: 11:42 am: 5.4 Chino Hills Earthquake, the greater Los Angeles metropolitan area experienced its largest earthquake in years as a magnitude 5.4 event occurred 8.5 miles beneath the Chino Hills. This earthquake was felt across much of southern California, and as far away as Las Vegas, Nevada. I was at a movie memorabilia auiction preview at the time and filming!

Monday January 17, 1994: 0430 PST 6.7 - Northridge: Sixty people were killed, more than 7,000 injured, 20,000 homeless and more than 40,000 buildings damaged in Los Angeles, Ventura, Orange and San Bernardino Counties.

April 18, 1906: 7.8 - One of the greatest earthquakes ever to hit California. Damage was extensive in San Francisco, and was increased perhaps tenfold by raging fires. Total damage was estimated at over $500 million. Seven hundred people died. The earthquake occurred on a blind thrust fault, and produced the strongest ground motions ever instrumentally recorded in an urban setting in North America. Damage was wide-spread, sections of major freeways collapsed, parking structures and office buildings collapsed, and numerous apartment buildings suffered irreparable damage.

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