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NR2009-19
October 23, 2009

Contact:  Ed Wilson
               Don Drysdale
               Carrie Reinsimar 

Reaching into a desk drawer, Dr. John Parrish pulls out a stack of paper. Each sheet is California’s potential salvation; more likely, it is a figment of someone’s imagination and a waste of time.

Each one is an earthquake prediction. Some are written by folks with serious scientific chops. Those discuss methodology, probability, algorithms and historic trends. Others might as well be written in Crayon. Those discuss the strange behavior of household pets, intuition, Aunt Agatha’s aching bunions, or other mysterious signs and portents that scientists simply don’t understand.

“We’re on the list of agencies that constantly receive warnings from researchers and whackos – us, the USGS, universities, radio stations … anyone who will listen,” Parrish said.

As the state geologist and head of the California Geological Survey, Parrish is also chair of the California Earthquake Prediction Evaluation Council (CEPEC). Little-known outside of the fields of earthquake science and emergency response, CEPEC has a big responsibility:  The council convenes at the request of the California Emergency Management Agency (CalEMA) to decide whether an earthquake prediction or an incident, such as swarm of small earthquakes, is serious enough to merit a warning to emergency responders or even the public at large.

CEPEC typically meets a couple of times a year, but is available 24-7. The members conduct a teleconference within several hours of a major temblor.
With the 20th anniversary of the Loma Prieta earthquake coming up, Parrish anticipates more – but not necessarily more accurate – quake predictions in the news. Some may require CEPEC’s attention.

“We’re asked to convene for a couple of reasons,” Parrish said. “CalEMA’s director might want to know about the validity of an earthquake prediction, so we’ll discuss whether the prediction meets the rules of engagement -- whether it’s something that can impact public policy decision-making. A lot of the predictions we get are very vague, along the lines of, ‘There’s going to be a large earthquake in northern California in the next year.’ That doesn’t meet our standards. We need a more specific location with a short time frame and a magnitude significantly larger than typical background earthquakes.

“The other reason we confer is if there has been an earthquake or a series of earthquakes, and we need to discuss whether we’re seeing foreshocks to a much larger, damaging quake.”

That was the case last March, when Parrish conducted a conference call with other CEPEC members to discuss an ongoing swarm of earthquakes just off the San Andreas Fault near the Salton Sea. CEPEC members also include retired CGS Chief Seismologists Michael Reichle; U.C. San Diego seismologist Duncan Agnew; James Brune of the University of Nevada Seismological Lab; Lucy Jones of USGS; Thomas Jordan of the University of Southern California and Southern California Earthquake Center; Jeanne Hardebeck, a seismologist with USGS in Menlo Park; Tom Heaton, a professor of engineering seismology at Caltech in Pasadena; and Jim Goltz of CalEMA’s Pasadena office.

At the time of the conference call, there had been more than 50 small earthquakes beginning early on the morning of March 21, including a magnitude 4.8 – not big enough to damage structures, but capable of grabbing people’s attention. The proximity of the swarm to the southern end of the San Andreas Fault, which scientists believe is overdue to produce a damaging quake, caused concern.

After much discussion, CEPEC advised CalEMA there was a greater-than-normal chance of a large earthquake as long as the swarm continued, but not to be overly alarmed.

“If there had been another earthquake during the swarm of magnitude 4.8 or greater, we might have advised CalEMA to go public with an advisory,” Parrish said. “But with every passing hour after the 4.8, the probability of a large earthquake decreased quickly.”

Ultimately, the swarm produced nearly 400 small quakes by the end of March. It petered out without producing the dreaded “Big One.”
Parrish has about as much faith in the Tooth Fairy as in most prognostications.

“Bottom line, there is no method known today to predict earthquakes, period,” he said. “There are a lot of false prophets out there – ‘faults’ prophets, if you will. There’s one who’s constantly on a San Francisco radio station making predictions, any number of people on the Web, a fellow who calls himself the `earthquake guy’ who predicts quakes based on the snowpack in the Midwest, a guy in India who predicts earthquakes based on cloud patterns. They’re all off-base.

“And there are other people who say things like, `on such-and-such a date, there will be four magnitude 5 quakes around the world and two magnitude 4s in California.’ The problem with those predictions is that the number and magnitude of those earthquakes aren’t all that unusual. Anyone could make that prediction for any day of the week and possibly be right, so it’s not real helpful.”

A couple of verbatim recent samples from CEPEC’s collection of predictions:

♦ (Dated February 15, 2009): “There is presently an earthquake swarm happening at Puerto Rico that adds up to 250 Richters and when you combine that with the 300 plus Richters that struck out at Indonesia in the days following the recent full moon, it all now tells me that our West Coast just might be next!!! Wind speeds in the recent tornado that struck Oklahoma City were reported as high as 170 mph and there has been an enormous amount of damage reported from there.”

♦ (Dated January 27, 2009): “I have so much information that I’m almost afraid to tell anyone for fear of letting the cat of the bag to soon. This information could, one day, lead to a Nobel prize … Based on my system, there will be a 7.0M+ earthquake somewhere in the world on Thursday. There should also be a 4.0M+ quake here in California on the same day or within 2 to 4 days, with the second and the fourth day being the most likely. As we get closer to Thursday, I may have certain symptoms that will allow me to determine if the quake will be in Southern California or not …”

As for the Loma Prieta earthquake, former Santa Clara County Geologist Jim Berkland notified the Gilroy Dispatch on October 12, 1989 that there would be a quake ranging from magnitude 3.5 to 6.0 during the World Series. He claims to have predicted three out of every four temblors in California since 1974, using tides, lunar cycles and animal behavior. Mainstream science rejects his claims, saying that Berkland is generally too vague in his warnings.
While CGS has no mandate to work on earthquake prediction, Parrish noted that a significant amount of legitimate research is being carried out by the USGS and other scientific organizations.

“Those folks come up with statistical analyses, they take a scientific approach, they have their papers peer-reviewed, and they don’t make outrageous claims,” Parrish said. “The problem with most of their results is that they’re too broad, too non-specific to be useful for making public policy decisions.

“It’s a potentially lucrative business, but the fact is we don’t yet have the tools or knowledge to understand what triggers an earthquake.  It’s like predicting the weather: too many variables. Meteorology has made big strides with all their new tools, but they still get it wrong much of the time.”

However, Parrish is a firm believer in the potential of early warning systems. CGS is part of the California Integrated Seismic Network, which, hopes to develop a warning system similar to the one in place in Japan.

“Japan has a very sophisticated system with an accuracy rate of 60 to 70 percent, so far,” Parrish said. “Mexico City has an early warning system, too. The problem in California is that our cities are right on top of the faults. In Mexico and Japan, the cities tend to be farther away from dangerous faults. So while they might get a minute and a half or two minutes of warning, we might get 10 to 15 seconds.”

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