U.S. Races to Develop New Tsunami Warning System
RENEE MONTAGNE, host:
The earthquakes that have rocked the eastern Indian Ocean since last December may not be finished. Scientists say stresses in the Earth's crusts have continued to build up off the coast of Sumatra in Indonesia. This finding comes as governments negotiate what kind of warning system to create for the region. NPR's Christopher Joyce has more on the story.
CHRISTOPHER JOYCE reporting:
John McCloskey spent years studying something that only a few people cared about, the faults and tectonic plates that undercut the Indian Ocean. Then on December 26th, one of those plates violently thrust itself under an adjoining plate. The earthquake and tsunami that followed killed some 200,000 people and 100,000 more are still missing. Two and a half months later, McCloskey, a geophysicist at the University of Ulster in Northern Ireland, wrote a scientific paper warning that another quake could be on the way. Eleven days later, in March, it happened southeast of the first one. There was no tsunami, but about 2,000 people in Indonesia died. McCloskey now says a third seismic domino is ready to fall.
Mr. JOHN McCLOSKEY (Geophysicist, University of Ulster): We're pretty confident that the mechanism for this domino effect is the stress transfer between these earthquakes. So when one happens, it distorts the Earth's crust and produces stress on the other. And it's where we see these strong transfers onto places that haven't ruptured, then the hazard increases.
JOYCE: He doesn't know when it might happen, but he's pretty sure where, along the Sunda trench. It's a massive seabed fault that runs roughly parallel with the west coast of Sumatra. The two earthquakes of December and March struck along this fault. McCloskey believes they relieved stress in some places but raised it in others. The stressed regions lay under the Batu and Mentawai Islands. These sections of the fault have a history of spawning serious earthquakes.
Mr. McCLOSKEY: Unfortunately, in this case, we find that areas within the increased stress region have not ruptured since 1797. So there's been a significant buildup of--within the so-called seismic cycle. And that means that there appears to be a very significantly increased risk in this area.
JOYCE: The 1797 quake is believed to have been large. Another nearby in 1833 created a big tsunami.
Mr. McCLOSKEY: So this is a real live issue. We can't take our foot off the accelerator when we're thinking about tsunami warning systems.
JOYCE: McCloskey's research in collaboration with Caltech in the US appears in this week's issue of the journal Nature. It comes as government officials from Asia, the Pacific and the US meet in Hawaii to plan a Tsunami warning system for the Indian Ocean. The existing US tsunami system run by the National Oceanic and Atmospheric Administration only goes so far. It can detect earthquakes anywhere in the world, but for tsunamis, it only works in the Pacific. Curt Barrett, the agency's international tsunami team leader, says the system did detect the big quake last March near Sumatra. Countries in the Indian Ocean were warned in minutes, but no one knew if there might be a tsunami, as well.
Mr. CURT BARRETT (National Oceanic and Atmospheric Administration): So the warnings went out based just on the earthquake and actually a number of evacuations occurred. But you can't keep doing that because then you're going to erode the credibility and confidence the people have in the warning.
JOYCE: Barrett says the US is now committed to spending $16 1/2 million to create an Indian Ocean warning system. The United Nations and several other countries will collaborate. The effort includes a faster e-mail and phone links between Western scientists and officials in countries at risk. It will also educate coastal residents about tsunami hazards. And the US will seed the Indian Ocean with submerged buoys that are the best way to detect a passing tsunami and predict when it will reach shorelines. Barrett says all this will take two to three years, however. In the meantime, say experts, the best course when the Earth shakes is to get away from the water. Christopher Joyce, NPR News.
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