RENEE MONTAGNE, host:
Two years ago, an earthquake off the coast of Sumatra triggered a tsunami that killed nearly a quarter of a million people. Scientists say Asia is at risk for at least two more massive quakes. One could strike near the source of the 2004 tsunami, the other directly under Tokyo.
NPR's Richard Harris reports.
RICHARD HARRIS: The regions in Asia at grave risk for a devastating earthquake share something in common. Both have populations that have grown rapidly in recent decades, putting more people in harm's way. They both came up recently at the American Geophysical Union meeting in San Francisco. Kerry Sieh from Caltech has been studying the Sumatran coastline just north of the area that triggered the 2004 tsunami and has some not very reassuring news.
Professor KERRY SIEH (Geology, California Institute of Technology): We're primed for a giant earthquake. When that happens, the seafloor will suddenly lurch up over a distance of anywhere from a few hundreds to seven hundred kilometers and there'll be another tsunami.
HARRIS: Sieh and his colleagues have charted out the probable flow of waters from that wave. He finds that many more Indonesians are in harms way, compared with the tsunami of 2004.
Prof. SIEH: This particular part of the coast has a population about over three times higher or four times higher than the coast of Aceh.
HARRIS: And his new study shows that the tsunami won't just strike the coast.
Prof. SIEH: We see two river valleys where the tsunami actually extends up several kilometers. So that's a warning that people who live in those valleys need to have extra precautions even if they're two kilometers upstream.
HARRIS: People in this area don't need warning sirens, he says. They just need to realize that if they feel an earthquake that lasts more than a minute, they'd better run for high ground. In many places, the initial wave of the tsunami will arrive a half and hour or so after the quake. Places that lack high ground nearby need to construct tall structures that will survive a wave. Sieh travels frequently to Indonesia. He says groups trying to teach people how to react to a big earthquake are working diligently with limited resources.
Prof. SIEH: they're just not reaching enough people to really have as big effect as they should. So we might see savings of tens of thousands of lives, but not hundreds of thousands.
HARRIS: In contrast, Ross Stein from the U.S. Geological Survey says the people of Japan have paid a great deal of attention to earthquake risks there.
Mr. ROSS STEIN (U.S. Geological Survey): But with that said, they also have tremendous vulnerabilities.
HARRIS: That's because about a quarter of the population of Japan lives in or around Tokyo, which, as fate would have it, sits directly above an extremely active fault zone. And there's a lot at risk.
Mr. STEIN: Tokyo is Washington, D.C., Chicago, New York and Los Angeles, all wrapped into one. So think about that. It's the cultural center. It's the financial center. It's the government center. It's one place, and this place has been hammered three times in 400 years.
HARRIS: Stein presented a new calculation of quake risks for Tokyo at the American Geophysical Union meeting. He and his colleagues figure that there is a 30 percent chance that a very damaging earthquake will strike Tokyo sometime in the next 30 years. The Japanese government figures a quake of that magnitude could kill 11,000 people, destroy nearly a million buildings and cost a staggering $1 trillion.
Mr. STEIN: This is 10 times higher than the cost of Katrina. And it's higher than anybody's estimate for the vulnerability of the United States to earthquakes.
HARRIS: He says this event would be cruelly global in its impact. For example, Japan holds 17 percent of U.S. treasury bills and would have to sell off those assets and many others to pay for quake repair. So Stein calls the next big Tokyo quake a financial tsunami that will spread around the world.
Richard Harris, NPR News.
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