For California, 'The Big One' may not be an earthquake

I was intrigued to read that the US Geological Survey believes that California may be threatened one day by a 'perfect storm', one so great it would be several times more damaging - and more costly - than another major earthquake. They call their scenario 'ARKStorm'. This video clip outlines what they fear may happen one day.

The USGS points out that such storms have occurred in the past.

Beginning on Christmas Eve, 1861, and continuing into early 1862, an extreme series of storms lasting 45 days struck California. The storms caused severe flooding, turning the Sacramento Valley into an inland sea, forcing the State Capital to be moved from Sacramento to San Francisco for a time, and requiring Governor Leland Stanford to take a rowboat to his inauguration. William Brewer, author of “Up and down California,” wrote on January 19, 1862, “The great central valley of the state is under water—the Sacramento and San Joaquin valleys—a region 250 to 300 miles long and an average of at least twenty miles wide, or probably three to three and a half millions of acres!” In southern California lakes were formed in the Mojave Desert and the Los Angeles Basin. The Santa Ana River tripled its highest-ever estimated discharge, cutting arroyos into the southern California landscape and obliterating the ironically named Agua Mansa (Smooth Water), then the largest community between New Mexico and Los Angeles. The storms wiped out nearly a third of the taxable land in California, leaving the State bankrupt.




The 1861-62 series of storms were probably the largest and longest California storms on record. However, geological evidence suggests that earlier, prehistoric floods were likely even bigger. There is no scientific evidence to suggest that such extreme storms could not happen again. However, despite the historical and prehistorical evidence for extreme winter storms on the West Coast, the potential for these extreme events has not attracted public concern, as have hurricanes. The storms of 1861-62 happened long before living memory, and the hazards associated with such extreme winter storms have not tested modern infrastructure nor the preparedness of the emergency management community.

For further reading, Wikipedia has an interesting article on the floods of 1862, which affected not just California, but the entire West Coast of the USA.

The USGS's theory is attracting renewed - and worried - attention following the very damaging storms that hit California earlier this week.

The trouble is, one can study such events until one's blue in the face . . . but one can never really adequately prepare for them. When Mother Nature lets rip, she's going to tear you a new one, whether you've taken precautions or not. Sometimes the only thing one can do is hunker down under suitable cover, or - if no cover is available - get the hell out of the way until she's finished. I suspect that may be California's only option, given its vastly greater population today than when the last such storm hit in the 1860's . . . but would its people listen to an evacuation order? And could its roads carry so much traffic away from the danger zone in time?

Peter