Major earthquakes can be predicted months in advance, argues UCLA
seismologist and mathematical geophysicist Vladimir Keilis-Borok.
"Earthquake prediction is called the Holy Grail of earthquake
science, and has been considered impossible by many scientists," said
Keilis-Borok, a professor in residence in UCLA's Institute of Geophysics
and Planetary Physics and department of earth and space sciences. "It
is not impossible."
"We have made a major breakthrough, discovering the possibility of
making predictions months ahead of time, instead of years, as in
previously known methods," Keilis-Borok said. "This
discovery was not generated by an instant inspiration, but culminates 20
years of multinational, interdisciplinary collaboration 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 precursory earthquake patterns.
In June of 2003, this team predicted an earthquake of magnitude 6.4 or
higher would strike within nine months in a 310-mile region of Central
California whose southern part includes San Simeon, where a magnitude 6.5
earthquake struck on Dec. 22.
In July of 2003, the team predicted an earthquake in Japan of magnitude
7 or higher by Dec. 28, 2003, in a region that includes Hokkaido. 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 an
18-month period when the team predicted that an earthquake of magnitude
6.6 or more would strike within 120 miles from the epicenter of the 1992
Landers earthquake - an area
that includes Northridge. The magnitude 6.8 Northridge earthquake caused
some $30 billion in damage. The 1989 magnitude 7.1 Loma Prieta earthquake
fulfilled a five-year forecast the team issued in 1986.
Keilis-Borok's team now predicts an earthquake of at least magnitude
6.4 by Sept. 5, 2004, in a region that includes the southeastern portion
of the Mojave Desert, and an area south of it.
This
map is posted through the courtesy of The Southern Califormia Earthquake
Center, which has no association with the UCLA group's prediction.
The team has submitted a description of its new short-term earthquake
prediction research to Physics of the Earth and Planetary Interiors, a
leading international journal in geophysics.
Prediction by this method is based on observations of small earthquakes
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 of my
arm. The doctor sent me for an MRI to test whether this pain was preceded
by an unfelt deterioration of the muscles in the whole arm during the last
few months. If yes, the pain signals that the deterioration has escalated,
so I am in trouble, and need urgent medical treatment. If not, I may have
just hit something, the pain will subside, and it's of little concern. To
detect these symptoms in order of their appearance -
first emerged, first detected -
could seem more natural but it is much more difficult; we would not know
when and where to look for long-term deterioration.
"Similarly, we look backwards to make our earthquake predictions.
First, we search for quickly formed long chains of small earthquakes. Each
chain is our candidate to a newly discovered short-term precursor. In the
vicinity of each such chain, we look backwards, and see its history over
the preceding years - whether
our candidate was preceded by certain seismicity patterns. If yes, we
accept the candidate as a short-term precursor and start a nine-month
alarm. If not, we disregard this candidate."
In seismically active regions, the Earth's crust generates constant
background seismicity, which the team monitors for the symptoms of
approaching strong earthquakes. Specifically, they consider the following
four symptoms: small earthquakes become more frequent in an area (not
necessarily on the same fault line); earthquakes become more clustered in
time and space; earthquakes occur almost simultaneously over large
distances within a seismic region; and the ratio of medium-magnitude
earthquakes to smaller earthquakes increases.
One of the challenges in earthquake prediction has been to achieve a
high proportion of successful predictions, while minimizing false alarms
and unpredicted events. The team's current predictions have not missed any
earthquake, and have had its two most recent ones come to pass.
Still, not all seismologists are convinced. "Application of
nonlinear dynamics and chaos theory is often counter-intuitive,"
Keilis-Borok said, "so acceptance by some research teams will take
time. Other teams, however, accepted it easily."
Keilis-Borok, 82, has been working on earthquake prediction for more
than 20 years. A mathematical geophysicist, he was the leading
seismologist in Russia for decades, said his UCLA colleague John Vidale,
who calls Keilis-Borok the world's leading scientist in the art of
earthquake prediction. Keilis-Borok is a member of the National Academy of
Sciences, and the American Academy of Arts and Sciences, as well as the
Russian Academy of Sciences, and the European, Austrian and Pontifical
academies of science. He founded Moscow's International Institute of
Earthquake Prediction Theory and Mathematical Geophysics, and joined
UCLA's faculty in 1999.
His research team has started experiments in advance prediction of
destructive earthquakes in Southern California, Central California, Japan,
Israel and neighboring countries, and plans to expand prediction to other
regions.
Vidale, interim director of the Institute of Geophysics and Planetary
Physics, said, "Most seismologists agree that the ingredients of the
'tail wags the dog' method are sensible, but argue about the performance.
However, the proof is in the pudding, and Professor Keilis-Borok's methods
have now delivered several correct and impressive forecasts."
At the most recent stage of the research, four members of the team
worked at UCLA on the "tail wags the dog" method for short-term
prediction: Keilis-Borok; Peter Shebalin, geophysicist from the Russian
Academy of Sciences and Institute of the Physics of the Earth in Paris;
Purdue University mathematician and geophysicist Andrei Gabrielov; and
UCLA researcher Ilya Zaliapin, whose field is analysis of complex systems.
Keilis-Borok's team communicates the predictions to disaster management
authorities in the countries where a destructive earthquake is predicted.
These authorities might use such predictions, although their accuracy is
not 100 percent, to prevent considerable damage from the earthquakes -
save lives and reduce economic losses -
by undertaking such preparedness measures as conducting simulation alarms,
checking vulnerable objects and mobilizing post‑disaster services,
Keilis-Borok said.
During the last few years, the team was supported by the James S.
McDonnell Foundation.
How does Keilis-Borok compare this research with other discoveries he
has made over his scientific career?
"I think this is the strongest result we have obtained so
far," he said.
