California enormo-quake prediction: Cracks form between US boffins

Is destruction a certainty – or merely highly probable?

NASA and the US Geological Survey (USGS) experts are arguing over the likelihood of a major earthquake hitting southern California in the near future.

The debate began earlier this week when eggheads at NASA's Jet Propulsion Laboratory (JPL) posted a study suggesting that the chances of an earthquake magnitude five or greater occurring in the Los Angeles area within the next three years was 99.9 per cent. It said the chances that quake would be a magnitude six or greater were 35 per cent.

According to JPL, the potential quake in the La Habra region would also pose the threat of severing water mains serving Los Angeles, possibly creating further havoc in addition to quake damage.

But America's governing body on earthquakes isn't so sure about JPL's near-certainty of a major earthquake. The USGS said that its numbers had a significantly lower likelihood, around 85 per cent, that such a quake will hit the La Habra region in the three-year time frame.

"The earthquake rate implied by the 99.9 per cent probability is significantly higher than observed at any time previously in Southern California, and the lack of details on the method of analysis makes a critical assessment of this approach very difficult," the USGS said.

"Therefore, the USGS does not consider the analysis presented in this paper a reason to change our assessment of the hazard."

While not severe, a magnitude six earthquake is expected to damage some buildings. A 6.0 quake occurring last year in the San Francisco Bay Area's Napa region killed one person, injured about 200, trashed the area's vineyards, and shook tens of thousands of people out of bed over a wide distance.

The last catastrophic quake to hit Los Angeles was the 6.7 magnitude 1994 Northridge Earthquake, which killed 54 people and caused billions in damages to buildings and roads. The notorious Loma Prieta earthquake of 1989 was a magnitude 6.9.

The Los Angeles area remains the second-largest metro area in the US and, in addition to the film and television industries, technology giants including SpaceX, IBM, and Google maintain offices around LA employing thousands of workers. ®

[Here in the Bay Area, we don't get out of bed for anything less than a six these days – West Coast Ed]