A 7.8 magnitude Southern Californian earthquake — about the same as the recent Sichuan, China quake — would kill 1,800 people, injure 50,000 and wreak about $200 billion in damage, according to ShakeOut Scenario, a joint study by the U.S. Geological Survey (USGS) and the California Geological Survey.

The report, which was presented to Congress May 22, is the result of the collaboration of more than 300 scientists, engineers, and experts from other disciplines, according to a USGS statement.

To create the Scenario, geologists determined potential motion along the part of the San Andreas Fault with the greatest risk of rupture. Seismologists and computer scientists then modeled ground shaking. Engineers and building professionals used the models to estimate damage to the built environment, while social scientists evaluated emergency response, casualties, and the impact on economy and society.

The analysis is the most comprehensive look at what a major Southern California earthquake could mean and is the framework for "Golden Guardian '08" — California’s largest earthquake preparedness drill, set for November 13, 2008.

California has more than a 99 percent chance of registering a magnitude 6.7 or larger earthquake — and a 46 percent chance of a 7.5 or larger — within the next 30 years, according to USGS modeling study released in April. See the modeling study here.

For a copy of the full ShakeOut report, visit the ShakeOut Scenario page on the USGS website.