For scientists, Chile becomes the ideal lab for studying seismic activity
Monday, March 8, 2010
TALCA, CHILE -- When an aftershock nearly as big as Haiti's earthquake jolted this city on Friday, those already reeling from last month's huge quake shuddered in fear. But Jeff Genrich, a 53-year-old earthquake scientist from California, lolled in bed.
Staying still, Genrich said he tried to estimate the power of the seismic waves. "It didn't seem to me to be that big of a deal," he said. "I just enjoyed them."
Most people here are thoroughly rattled after an 8.8-magnitude quake, one of the most powerful on record, struck this swath of south-central Chile on Feb. 27, killing more than 450 people, buckling bridges and downing buildings. But earthquake scientists, many of them from the United States, immediately flocked to Chile to search for clues that will help them determine the coming of the next big one.
"It's very exhilarating," said Michael Bevis, a professor of geodynamics at Ohio State University who has been studying Chile's earthquake-prone geology for 17 years.
The sheer size of the quake, along with aftershocks so powerful they could be considered significant quakes in their own right, is providing scientists with a rare opportunity. Bevis, who is in the capital, Santiago, organizing teams of American scientists for field work, said the objective is to install sensors and collect data about post-quake ground movements.
"Time is very precious," Bevis explained. "If you don't get there till, say, two or three weeks afterwards, you've missed an important part of the signal, so everybody has a sense of urgency."
The first arrivals have been geophysicists and geodesists, scientists who study the curvature and movement of the Earth. Seismologists, who work with bulkier equipment, are on their way down. The quake is also going to attract structural and earthquake engineers, who will be keen to study how so many of Chile's buildings survived a quake so powerful.
"The race we're having is to get down there," Dana Caccamise, a geophysical engineer at Ohio State, said by phone from Ohio. A staff scientist at the university, he designs the kind of equipment scientists are using in Chile. "I think all branches of science will be interested in this disaster."
This quake has, to be sure, already made an impression. It changed the speed at which the Earth spins, prompting NASA scientists to estimate that the day has gotten shorter by a millionth of a second. It kicked up monster waves in the Pacific that destroyed whole towns.
Ben Brooks, a geologist at the University of Hawaii who is helping get teams of scientists to Chile, said the quake moved much of the continent. Buenos Aires moved four centimeters closer to Chile. The city of Concepcion, which was near the epicenter, moved three meters to the west.
He said about 50 data-collection stations already are strategically located along this ribbon-shaped country, which stretches nearly 2,900 miles, sandwiched by the Pacific to the west and the Andes range to the east.
Brooks said U.S. and Chilean scientists would like to install an additional 25 sensors, as fast as possible, in what he called "the rupture area," which includes a swath of pine forests and wine-growing valleys known as the Bio Bio and Maule regions.