The California Earthquake Advisory Plan
James D. Goltz, Ph.D. Earthquake and Tsunami Program Manager Johanna Fenton Earthquake and Tsunami Program Specialist Governor’s Office of Emergency Services
Why Earthquake Advisories?
Earthquakes tend to cluster in time 50% of California earthquakes are preceded by foreshocks (1/2)
5% of M5.0 earthquakes are followed by a larger earthquake within 3 days (1/20)
We do not want to miss a precursory event no matter how ambiguous
Earthquake Prediction and Advisories
Prediction
A statement of magnitude A defined location A defined time frame A statement of probability of occurrence
Advisory
Usually issued after an earthquake that might be a precursor to a larger damaging event Based on history and seismic potential CEPEC review precedes advisory
Time Frames
Prediction
Long Term -- Years to Decades Intermediate Term -- Weeks to Years Short Term -- Up to a Few Weeks
Advisory
Usually 3-5 days May be cancelled or extended Long-term advisories rare
Increased Probabilities After a M 5 Earthquake
.05 PROBABILITY .00025 1 2
Background 3
TIME (Days)
California Earthquake Prediction Evaluation Council
9 Scientists from government, universities or private sector, chaired by the State Geologist
Appointed by the OES Director Advise OES and the Governor on credibility of predictions and policy options
Provides immunities
CEPEC Rapid Assessment Plan
Post Earthquake (M>5) Conference Call Assessment of Probabilities ‘Follow-on’ Quake Issuance of Earthquake Advisories based on Recommendations of CEPEC Not every M5 generates an advisory
What OES Does
Convenes CEPEC Disseminates findings and notifications to counties and media Developed California Earthquake Prediction Response Plan Developed California Earthquake Advisory Response Plan Plans date to 1990-need revision
Notification Process
Local Government (also state and Federal agencies) will be notified via CLETS, CAWAS and Dialogic OAs are asked to forward message to county emergency services staff & cities OES will notify OAs approximately 30 minutes before release to the media
At the end of the period OES will, as appropriate, cancel or extend Advisory
OES Advice to Local Government
Disseminate information to key personnel
Ensure the readiness of systems essential to emergency operations
Implement protective and mitigative actions Provide guidance to the public on appropriate precautionary actions Possibly more…,
Advisories Considered/Issued
June 1985 July 1986 July 1986 October 1987 November 1987 June 1988 June 1988 August 1989 October 1989 April 1992 June 1992 November 2002 November 2004 October 2007
San Diego County (Issued) North Palm Springs (Not Issued) Chalfant Valley (Issued) Whittier Narrows (Not Issued) Superstition Hills (Not Issued) Gorman (Not Issued) Lake Elsman (Issued) Lexington Reservoir (Issued) Loma Prieta Humboldt (Not Issued) Landers-Big Bear (Issued) San Ramon Swarm (not Issued) Bombay Beach Swarm (not Issued) San Jose (Issued)
But….
The California Integrated Seismic Network (CISN) provides near real-time earthquake information on CISN display If the earthquake wasn’t predicted, you can still find out about it at:
www.cisn.org