Screw the "Big One": a coming storm of biblical proportions may prove to be an even greater threat to Southern California than a mega-earthquake along the dreaded San Andreas fault.
So say more than 100 scientists and experts gathered by the U.S. Geological Survey (USGS) to create an "ARkStorm Scenario" that produced a hypothetical storm that showered the region with 10 feet of rain, caused extensive flooding and resulted in more than $300 billion in damage.
Unveiled at a Sacramento summit last week, the ARkStorm relied on California's prehistoric geologic flood history, modern flood mapping and climate-change projections. Its architect is Lucy Jones, the chief scientist of the USGS Multi-Hazards Demonstration Project and the seismologist out of Caltech the media has been going to for decades whenever big shakers strike California.
"The ARkStorm scenario is a complete picture of what that storm would do to the social and economic systems of California," Jones says in a USGS release. "We think this event happens once every 100 or 200 years or so, which puts it in the same category as our big San Andreas earthquakes."
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The last such mega-storm is believed to have happened in 1861 and lasted for 45 days, flooding extensive areas of the state. Based on Jones' projections, that means the next one could strike during the lifetime of anyone reading this.
To give an idea of what kind of wallop they are talking about, last month's "seven-day storm" that dropped record rainfall on Southern California was a mere, well, drop in the bucket. One-quarter of all homes in the state could suffer flood damage in such a storm, according to Jones.
Marcia McNutt, the USGS director, says in the same release that the information spread at the ARkStorm summit will help communities, first-responders and elected officials buck up for the inevitable.
"The time to begin taking action is now," she warns, "before a devastating natural-hazard event occurs."