October 4, 2004
EARTHQUAKE FORECAST PROGRAM HAS AMAZING SUCCESS RATE
A NASA funded earthquake prediction program has an amazing track record. Published in 2002, the Rundle-Tiampo Forecast has accurately predicted
the locations of 15 of California’s 16 largest earthquakes this decade, including last week’s tremors.
The 10-year forecast was developed by researchers at the University of Colorado (now at the University of California (U.C.), Davis) and from
NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif. NASA and the U.S. Department of Energy funded it.
“We’re elated our computer modeling technique has revealed a relationship between past and future earthquake locations,” said
Dr. John Rundle, director of the Computational Science and Engineering initiative at the U.C. Davis. He leads the group that developed the forecast
scorecard. “We’re nearly batting a thousand, and that’s a powerful validation of the promise this forecasting technique
holds,” he said.
Of 16 earthquakes, magnitude 5 and higher since Jan. 1, 2000, 15 fall on “hotspots” identified by the forecasting approach. Eleven of
the 15 quakes occurred after the paper was published in Proceedings of the National Academy of Sciences in Feb. 2002. The scorecard uses records of
earthquakes from 1932 onwards to predict locations most likely to have quakes of magnitude 5 or greater between 2000 and 2010. According to Rundle,
small earthquakes of magnitude 3 and above may indicate stress is building up along a fault. While activity continues on most faults, some of those
faults will show increasing numbers of small quakes, building up to a big quake, while some faults will appear to shut down. Both effects may herald
the possible occurrence of large events.
The scorecard is one component of NASA’s QuakeSim project. “QuakeSim seeks to develop tools for quake forecasting. It integrates
high-precision, space-based measurements from global positioning system satellites and interferometric synthetic aperture radar (InSAR) with
numerical simulations and pattern recognition techniques,” said JPL’s Dr. Andrea Donnellan, QuakeSim principal investigator. “It
includes historical data, geological information and satellite data to make updated forecasts of quakes, similar to a weather forecast,” she
said.”
JPL software engineer Jay Parker said, “QuakeSim aims to accelerate the efforts of the international earthquake science community to better
understand earthquake sources and develop innovative forecasting methods. We expect adding more types of data and analyses will lead to forecasts
with substantially better precision than we have today.”
The scorecard forecast generated a map of California from the San Francisco Bay area to the Mexican border, divided into approximately 4,000
boxes, or “tiles.” For each tile, researchers calculated the seismic potential and assigned color-coding to show the areas most likely to
experience quakes over a 10-year period.
“Essentially, we look at past data and perform math operations on it,” said James Holliday, a U.C. Davis graduate student working on
the project. Instrumental earthquake records are available for Southern California since 1932 and for Northern California since 1967. The scorecard
gives more precision than a simple look at where quakes have occurred in the past, Rundle said.
“In California, quake activity happens at some level almost everywhere. This method narrows the locations of the largest future events to
about six percent of the state,” Rundle said. “This information will help engineers and government decision makers prioritize areas for
further testing and seismic retrofits.”
So far, the technique has only missed one earthquake, a magnitude of 5.2, on June 15, 2004, under the ocean near San Clemente Island. Rundle
believes this “miss” may be due to larger uncertainties in locating earthquakes in this offshore region of the state. San Clemente Island
is at the edge of the coverage area for Southern California’s seismograph network. Rundle and Holliday are working to refine the method and
find
new ways to visualize the data.
Other forecast collaborators include Kristy Tiampo, the University of Western Ontario, Canada; William Klein of Boston University, Boston; and
Jorge S. Sa Martins, at the Universidad Federal Fluminense, Rio de Janeiro, Brazil.
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Contacts:
Gretchen Cook-Anderson
Headquarters, Washington
Phone: 202/358-0836
Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
Phone: 818/354-0474
Andy Fell
University of California, Davis, Calif.
Phone: 530/752-4533
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15 Predicted Quakes
Fifteen large earthquake events over a 5 magnitude occurred in Calif. or So. Calif. They are depicted above by the blue circles numbered 1-15. The
most recent 11 events, numbered 5-15, occurred after the research was published on February 19, 2002 in Proceedings of the National Academy of
Sciences USA.
The numbers correspond with the following quakes, and M = Magnitude.
1. Bodie I, M = 5.0, 1/21/00; 2. Big Bear I, M = 5.1, 2/10/01; 3. Coso, M = 5.1, 7/17/01 4. Anza, M = 5.1, 10/31/01; 5. Baja, M = 5.7, 2/22/02; 6.
Gilroy, M=4.9 - 5.1, 5/13/02; 7. Big Bear II, M=5.4, 2/22/03; 8. San Simeon, M = 6.5, 12/22/03; 9. San Clemente Island, M = 5.2, 6/15/04; 10. Bodie
II, M=5.5, 9/18/04; 11. Bodie III, M=5.4, 9/18/04; 12. Parkfield I, M = 6.0, 9/28/04; 13 Parkfield II, M = 5.0, 9/28/04; 14. Parkfield III, M=5.2,
9/29/04; 15. Arvin, M= 5.0, 9/29/04
Credit: UC Davis
Damaged Historic Paso Robles, Ca
This January 25, 2004 photo shows historic structures and a vehicle damaged in downtown Paso Robles from the 6.5 San Simeon Earthquake. Credit:
Dane Golden/FEMA
Interstate 800 Collapse
This is a collapsed section of the Cypress viaduct of Interstate 880 in Oakland, from the Loma Prieta California, Earthquake October 17, 1989.
Credit: USGS, H.G. Wilshire
Loma Prieta, California, Earthquake October 17, 1989
Collapsed and burned buildings shown at Beach and Divisadero in the Marina District, San Francisco.
Credit: USGS, C.E.Meyer
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