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More Earthquake Coverage

When the next big earthquake hits the San Francisco Bay Area, it will be a catastrophe of Hurricane Katrina proportions. Hundreds, perhaps thousands of people will die, and hundreds of thousands will become homeless. Economic losses will be on the order of $200 billion, the vast majority of it uninsured.

Outside help will be desperately needed, but difficult to coordinate and execute.

And just like before Hurricane Katrina, scientists have been sounding the alarm, warning that the disaster is inevitable. It’s not a matter of if, but when the “Big One” will strike.

“The reality is that we could have a large earthquake at any time,” said geologist David Schwartz of the U.S. Geological Survey.

The Bay Area is lined with faults capable of delivering a knock-out blow. But one in particular is poised to rupture at any time. Geologists have determined that the average time between major earthquakes on the Hayward fault is 140 years. The last big one was 140 years ago today.

The 1868 Hayward fault earthquake measured around a magnitude 7 and offset the ground laterally more than six feet in places. It killed 30 people in the sparsely populated area and leveled or severely damaged nearly every structure in a wide swath along its 160-mile length. It was known as the Great San Francisco Earthquake until the 1906 earthquake took that title away.

But if the 1868 quake were to strike again today, it would do exponentially more damage. The Hayward fault lies along the hills on the eastern side of the San Francisco Bay in one of the most densely populated areas of the state. It runs beneath homes, schools, senior centers, hospitals, businesses and through the campus of UC Berkeley, bisecting the football stadium.

“A Hayward fault earthquake will change the Bay Area,” said USGS geologist Tom Brocher. “It’s likely to be one of the nation’s biggest natural disasters.”

more via wired science