If you follow Twitter for mentions of Berkeley like we do, you may have been startled yesterday to find this scary tweet: “36 HOUR EARTHQUAKE WARNING; 5.0 to 6.0 earthquake likely in the Berkeley, Oakland area Nov 11-12″.
With updates every few hours, this all caps alert has been retweeted dozens of times. What none of the retweets mention, however, is that the origin of the tweets, the serious-sounding QuakePrediction.com, is a confection of pseudoscience and should be ignored.
“We cannot do earthquake prediction yet. Nobody can do earthquake prediction yet,” said Peggy Hellweg, a research seismologist at the Berkeley Seismological Laboratory at UC Berkeley. Hellweg looked at QuakePrediction.com when Berkeleyside called her and said the information presented there is “not what we know about seismic hazard” (I’m not providing a link to the site because I don’t want to add to the credibility of the site or provide click throughs that will give the creator some ad revenue).
What Hellweg does urge, however, is that Berkeleyans remain aware of the serious earthquake forecasts (not predictions) that seismologists do support. According to Hellweg, seismologists have been able to identify 12 major earthquakes along the Hayward fault in the past 2,000 years. That suggests a major quake every 150 years, plus or minus 40 years. The last major quake along the Hayward fault was on October 21, 1868, 142 years ago.
“This is earthquake country,” said Hellweg. “As my boss says when someone asks whether we’re surprised by an earthquake, ‘How can anyone be surprised that there are earthquakes in California?’”
In addition to the Hayward fault, the Bay Area has the San Andreas fault and the Calaveras fault, as well as others. But major quakes can also occur on so-called blind thrust faults, explained Hellweg, which may not have been identified. The 2003 San Simeon, the 1994 Northridge and the 1983 Coalinga quakes were all on blind thrust faults.
“It will pay to be prepared,” said Hellweg. Among the resources on earthquake preparedness are the Bay Area Earthquake Alliance, which includes links to other sites and information.