Science + Technology

Earthquakes Can Be Predicted Months in Advance, Report UCLA Scientists, Who Predicted San Simeon Earthquake

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Major earthquakes can be predicted months in advance, arguesUCLA seismologist and mathematical geophysicist Vladimir Keilis-Borok.

"Earthquake prediction is called the Holy Grail ofearthquake science, and has been considered impossible by many scientists,"said Keilis-Borok, a professor in residence in UCLA'sInstitute of Geophysics and Planetary Physics and department of earth and spacesciences. "It is not impossible."

"We have made a major breakthrough, discovering thepossibility of making predictions months ahead of time, instead of years, as inpreviously known methods," Keilis-Borok said."This discovery was not generated by an instant inspiration, butculminates 20 years of multinational, interdisciplinarycollaboration by a team of scientists from Russia, the United States,Western Europe, Japan and Canada."

The team includes experts in pattern recognition,geodynamics, seismology, chaos theory, statistical physics and public safety.They have developed algorithms to detect precursoryearthquake patterns.

In June of 2003, this team predicted an earthquake ofmagnitude 6.4 or higher would strike within nine months in a 310-mile region ofCentral California whose southern part includes San Simeon, where a magnitude6.5 earthquake struck on Dec. 22.

InJuly of 2003, the team predicted an earthquake inJapan of magnitude 7 or higher by Dec. 28, 2003, in a region that includesHokkaido. A magnitude 8.1 earthquake struck Hokkaido on Sept. 25, 2003.

Previously, the team made "intermediate-term" predictions,years in advance. The 1994 Northridge earthquake struck 21 days after an18-month period when the team predicted that an earthquake ofmagnitude 6.6 or more would strike within 120 miles from the epicenter of the1992 Landers earthquake an area that includes Northridge. The magnitude 6.8 Northridgeearthquake caused some $30 billion in damage.The 1989 magnitude 7.1 Loma Prieta earthquake fulfilled afive-year forecast the team issued in 1986.

Keilis-Borok'steam now predicts an earthquake of at least magnitude6.4 by Sept. 5, 2004, in a region that includes the southeastern portion of theMojave Desert, and an area south of it.

Theteam has submitted a description of its new short-term earthquake predictionresearch to Physics of the Earth and Planetary Interiors, a leadinginternational journal in geophysics.

Prediction by this method is based on observations of smallearthquakes that occur daily.

"We call our new approach, 'tail wags the dog,'"Keilis-Borok said. "For example, I recently had a sharp pain in a small area ofmy arm. The doctor sent me for an MRI to test whether this pain was preceded byan unfelt deterioration of the muscles in the whole arm during the last fewmonths. If yes, the pain signals that the deterioration has escalated, so I amin trouble, and need urgent medical treatment. If not, I may have just hitsomething, the pain will subside, and it's of little concern. To detect thesesymptoms in order of their appearance first emerged, first detected could seem more natural but it is much more difficult; we would not know whenand where to look for long-term deterioration.

"Similarly, we look backwards to make our earthquakepredictions. First, we search for quickly formed long chains of smallearthquakes. Each chain is our candidate to a newly discovered short-termprecursor. In the vicinity of each such chain, we look backwards, and see itshistory over the preceding years whether our candidate was preceded by certain seismicity patterns. If yes, weaccept the candidate as a short-term precursor and start a nine-monthalarm. If not, we disregard thiscandidate."

In seismically active regions, the Earth's crust generatesconstant background seismicity, which the team monitors for the symptoms ofapproaching strong earthquakes. Specifically, they consider the following foursymptoms: small earthquakes become more frequent in an area (not necessarily onthe same fault line); earthquakes become more clustered in time and space;earthquakes occur almost simultaneously over large distances within a seismicregion; and the ratio of medium-magnitude earthquakes to smaller earthquakesincreases.

One of the challenges inearthquake prediction has been to achieve a high proportion of successfulpredictions, while minimizing false alarms and unpredicted events. The team'scurrent predictions have not missed any earthquake, and have had its two mostrecent ones come to pass.

Still, not all seismologists are convinced. "Application ofnonlinear dynamics and chaos theory is often counter-intuitive," Keilis-Boroksaid, "so acceptance by some research teams will take time. Other teams,however, accepted it easily."

Keilis-Borok, 82, has been working on earthquake predictionfor more than 20 years. A mathematical geophysicist, he was the leadingseismologist in Russia for decades, said his UCLA colleague John Vidale, whocalls Keilis-Borok the world's leading scientist in the art of earthquakeprediction. Keilis-Borok is a member of the National Academy of Sciences, andthe American Academy of Arts and Sciences, as well as the Russian Academy ofSciences, and the European, Austrian and Pontifical academies of science. He founded Moscow's International Institute of EarthquakePrediction Theory and Mathematical Geophysics, and joined UCLA's faculty in1999.

His research team has started experiments in advanceprediction of destructive earthquakes in Southern California, CentralCalifornia, Japan, Israel and neighboring countries, and plans to expandprediction to other regions.

Vidale, interim director of theInstitute of Geophysics and Planetary Physics, said, "Most seismologists agreethat the ingredients of the 'tail wags the dog' method are sensible, but argueabout the performance. However, the proof is in the pudding, and Professor Keilis-Borok'smethods have now delivered several correct and impressive forecasts."

At the most recent stage of the research, four members ofthe team worked at UCLA on the "tail wags the dog" method for short-termprediction: Keilis-Borok; Peter Shebalin, geophysicist from the Russian Academyof Sciences and Institute of the Physics of the Earth in Paris; PurdueUniversity mathematician and geophysicist Andrei Gabrielov; and UCLA researcher Ilya Zaliapin, whose field isanalysis of complex systems.

Keilis-Borok's team communicates the predictions to disaster management authorities in the countries where a destructive earthquake ispredicted. These authorities might use such predictions, although theiraccuracy is not 100 percent, to prevent considerable damage from theearthquakes save lives and reduce economic losses — byundertaking such preparedness measures as conducting simulation alarms,checking vulnerable objects and mobilizing post‑disaster services, Keilis-Borok said.

During the last few years, theteam was supported by the James S. McDonnell Foundation.

How does Keilis-Borok compare this research with otherdiscoveries he has made over his scientific career?

"I think this is the strongest result we have obtained sofar," he said.

-UCLA-

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