Asia Tsunami Quake Stronger than First Thought
USA: May 23, 2005


WASHINGTON - The earthquake that triggered Asia's deadly tsunami in December was more powerful than scientists originally estimated, according to new studies published in Friday's edition of Science.

 


"The Earth is still ringing like a bell today," nearly six months after the Sumatra-Andaman earthquake, Roland Burgmann, professor of earth and planetary science at the University of California, Berkeley, told the journal.

The quake generated a tsunami that killed about 300,000 people in states around the Indian Ocean.

"We've never been able to study earthquakes of this magnitude before, where a sizable portion of the Earth was distorted," said Burgmann, one of the authors of the study.

According to the study, researchers now believe the quake had a magnitude of 9.15. Initial measurements put the quake at 9.0 on the Richter scale, making it the fourth-largest quake since 1900.

Burgmann said adjustments in the earth's mantle could have triggered a magnitude 8.7 earthquake in the same area on March 28.

The quake also set records for the longest fault rupture and the longest duration of faulting, the researchers reported.

Burgmann and other scientists who studied data from the quake found it caused deformations of the earth's crust as far away as 2,800 miles (4,500 km) -- five or six times the deformations caused by previous big quakes, the study said.

In another study published in Friday's edition of Science, Yale University professor Jeffrey Park said the quake's rupture moved giant slabs of rock at least 65 feet (20 metres) over a record distance equivalent to that between Florida and New England.

Park warned the Sumatra-Andaman earthquake would continue to affect the region for many years and could trigger more large quakes.

 


REUTERS NEWS SERVICE