California Earthquake Prediction Evaluation Council
The California Earthquake Prediction Evaluation Council (CEPEC) is a committee of earthquake experts that reviews potentially credible earthquake predictions and forecasts. Its purpose is to advise the Governor of California via the California Office of Emergency Services.
As the state geologist and head of the California Geological Survey, Dr. John Parrish is 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.
As an example, following a June 14, 2010 M 5.7 earthquake the CEPEC issued the following statement. "The earthquake was the largest aftershock so far of the Mw 7.2 El Mayor-Cucapah earthquake that occurred on Easter Sunday. This earthquake occurred at the northern end of the aftershock zone in an area where there has been considerable activity during the past 10 weeks. The Mw 5.7 earthquake rapidly was followed by a tight cluster of over 30 smaller earthquakes, about 20 of which were in the range of Mw 3.0 to 4.5.
"CEPEC convened a teleconference call at 22:30 hrs PDT to discuss the implications of the aftershock. It occurred along the southernmost portion of the Elsinore Fault Zone, which has not had a major earthquake in the past 100 years or so. Because of the location of the Mw 5.7 aftershock , CEPEC believes that the probability of a larger event on the Elsinore Fault or the San Jacinto Fault Zone has increased considerably, and will remain so for several days, although the absolute probability remains low, on the order of one percent. CEPEC will continue to monitor the situation."
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.
As of 2006, CEPEC and the state of California has never advised any action be taken by the government or residents based on an earthquake prediction.