Newsweek, described the "four corners" theory about the Pacific Plate and how it relates to California. Japan sits "at the junction of a web of tectonic-plate boundaries that make it more peculiarly vulnerable to ground-shaking episodes than almost anywhere else. Three sides of the square have been hit in the last year, leaving one still to come.
The three sides that erupted commencing with 2010's 8.8 quake in Chile, the temblor in New Zealand almost exactly a year later in February 2011 and now the 9.0 devastating event in Japan. That leads experts to point to the last corner of the plate, which is the San Andreas Fault that runs through the southern California desert.
Newsweek reported that when one side of a tectonic plate shifts, "the Earth becomes like a great brass bell, which when struck by an enormous hammer blow on one side sets to vibrating and ringing from all over."
There might be good news for California residents however. "Good" is a relative term when it comes to earthquakes but the U.S. Geological Survey believes a San Andreas event will top out at 7.8 on the Richter scale. The USGS predicts a 46% chance of a quake that size erupting in the next 30 years.
When that happens, Reuters reported that a damage report made for the USGS predicts "...a calamity that would leave 2,000 people dead, 50,000 injured and 250,000 homeless.topple 1,500 buildings, badly damage another 300,000 and sever highways, power lines, pipelines, railroads, communications networks and aqueducts. Property losses of more than $200 billion are projected."
There are two nuclear power plants proximate to a quake along the predicted fault line, the Southern California Edison-owned San Onofre station between Los Angeles and San Diego.and Edison and Pacific Gas & Electric, owned of the Diablo Canyon plant to the north at San Luis Obispo.
Both company owner-operators are certain that their facilities were built to withstand any size quake that comes within those predicted levels. They both have gravity-based backup cooling systems as well as emergency diesel generators.
Would there be a tsunami risk with a quake of that magnitude in Southern California. No say geological experts because off the coast there isn't an area in which one tectonic plate would slide under another to cause the wall of water. Nonetheless, San Onofre is protected by a 30-foot-tall reinforced "tsunami wall," and Diablo Canyon sits atop an 85-foot cliff.
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