Berkeley quakes put city on edge, but don't herald a major temblor
Suzanne Bohan Contra Costa Times
It warned of a 30 percent chance of a major quake striking within the next two or three weeks, credited to scientists at the U.S. Geological Survey who allegedly met with Berkeley city officials.
It's bogus, said Keith Knudsen, deputy director of the USGS Earthquake Science Center in Menlo Park.
"I don't know of any scientific organization that would make a statement like that," he said. "We didn't."
City Hall also debunked the email.
But its rapid spread underscores how jittery the quakes have made some people.
Since Oct. 20, four earthquakes of 3.0 magnitude or greater have hit the region. Three were centered near Berkeley along the Hayward fault, and one near Danville along a different fault. On Monday morning, two smaller Hayward fault quakes, magnitudes 2.4 and 1.7, shook the on-edge city, said Peggy Hellweg, a UC Berkeley seismologist.
Nothing unusual about a spate of shaking in earthquake country, Knudsen said.
"They're pretty characteristic of what happens on the Hayward fault, although maybe just slightly bigger and a little more energetic."
Small quakes sometimes precede large ones, but not always, Knudsen said. After analyzing the cluster, he said, the USGS is sticking to its prediction that there's a 30 percent chance the Hayward fault could rupture in the next 30 years, unleashing a magnitude 6.7 or higher quake.
The Berkeley area has had similar clusters in the past decade, Hellweg said. In December 2003, three 3.0-plus temblors struck on the same day. In September 2006, four of at least magnitude 3.0 jolted the city.
"And there was no earthquake after those," she said. "This earthquake activity is very normal."
Seismologists support one aspect of the bogus email -- always be ready for the Big One.
"Far be it for me to dissuade people from being prepared," Knudsen said. "We wholeheartedly endorse that."
Oct. 31, 2011
http://www.mercurynews.com/bay-area-news/ci_19234288