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No easy system to warn of disaster
By John Schwartz
The New York Times, Thursday, December 30, 2004
NEW YORK -- If only people had been warned. An hour's notice for those
living and vacationing along the coastlines of the Indian Ocean might
have saved thousands of lives.
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But predictions, and acting on them, are not simple, geoscience experts
say.
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"It's an inexact science now," said Laura S.L. Kong, a U.S. Commerce
Department seismologist and director of the International Tsunami
Information Center, an office in Honolulu run under the auspices of the
United Nations.
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According to a NASA Web site devoted to tsunamis, three-fourths of
tsunami warnings issued since 1948 have been false, and the cost of the
false alarms can be high.
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An evacuation in Hawaii could cost as much as $68 million in lost
productivity, according to the National Oceanic and Atmospheric
Administration. Since the 1960s, Kong said, there have been two
warnings of tsunamis in Hawaii that ended in evacuations, and both were
false alarms.
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Kong said that the predictions of tsunamis were accurate: The waves do
arrive, whether they are 40 feet high, or 12 meters, or a hundredth of
that. It is the destructive power of the wave that is hard to predict.
That depends on many factors, including the configuration of the ocean
floor and the shape of a bay.
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Tsunamis, which are common in the Pacific Ocean, are rare in the Indian
Ocean. And the earthquake that set the waves in motion Sunday was
uncommonly powerful.
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But an Indian Ocean tsunami was, to a certain extent, predictable - and
scientists from Geoscience Australia, that nation's agency for earth
science research, issued a paper last fall describing the tsunami
generated by sea-floor disturbances after the explosion of the volcano
Krakatau in 1883, with charts that showed an uncanny resemblance to the
wave of destruction that accompanied this week's disaster.
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Australia has established a tsunami warning center of its own, which
issued an alert 33 minutes after the quake occurred.
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Kong said her e-mail box had filled in recent days with the signs of a
scramble by UN organizations and affected governments hoping to create
a new warning system for the Indian Ocean. Such a system could be
cobbled together, in part, by depending on ocean-measuring sites
already in place, she said.
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The lowest-cost components are water-level gauges, which can be had for
as little as $5,000 apiece but which can cost $20,000 or more if they
are equipped with better instruments and quick communication abilities.
A system could be put into place relatively quickly, she said, for
"millions or tens of millions" of dollars.
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She said such a system would not include tsunameters, a new generation
of deep-sea sensors that are the gold standard for tsunami measurement.
These devices "wake up" when a tsunami passes over, and transmit data
to satellites, which then pass the signal along to warning centers.
There are only seven tsunameters in use, and they can cost $250,000
apiece, with annual maintenance costs of $50,000.
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Richard Posner, the author of "Catastrophe: Risk and Response," said
tsunamis in the Indian Ocean had a low probability of occurrence but a
high risk of damage. A disaster may occur only every 100 years and kill
40,000 people, Posner said, but "one way to think about it is, that's
an average of 400 people killed each year."
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Warning the public of disaster is an age-old problem with modern
implications, said Kenneth Allen, executive director of the Partnership
for Public Warning, a public-private partnership devoted to improving
crisis communications after the terrorist attacks of Sept. 11, 2001.
Educational campaigns are an essential part of any warning system,
Allen said.
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"You need to tell people how they are going to get information in an
emergency, and what to do about it," he said. "If you wait until the
emergency occurs, it's too late."
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Phil McFadden, chief scientist of Geoscience Australia, said warnings
without such training were useless.
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"If all you do is phone up the local police station, they don't know
what to do," he said. "And in fact, one of the problems is that if you
tell untrained people, 'Listen - there's a tsunami coming,' half of
them go down to the beach to see what a tsunami looks like."
Contributing reporting were Andrew C Revkin of The New York Times from New York
and Thomas Fuller of the International
Herald Tribune from Paris
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