Another tsunami could hit Indonesia, experts say
UNITED STATES: Another big tsunami could hit Sumatra within the next
few decades, flooding densely populated regions south of where a giant
wave hit in December 2004, U.S. and Indonesian researchers predicted.
The same big geologic fault, called a megathrust, that caused the
2004 tsunami continues to run parallel to the southeast, along the
Indian Ocean coast of Sumatra, with the potential to a affect areas to
the south, the team at the California Institute of Technology, the
University of Southern California and elsewhere reported.
Pressure is building and it could move at any time, they said.
"Potential losses could be as great as those that occurred in Aceh in
2004," the researchers wrote in their report, published in this week's
issue of the Proceedings of the National Academy of Sciences.
Movements along this section caused two big quakes and tsunamis in
1797 and 1833, the researchers reported. They used a combination of
history and geology to predict what might happen again.
"When we tell people living along this 700-kilometer (435 mile)
section of the Sumatran coast that they will likely experience a big
tsunami within the next 30 years, they ask for details," said Kerry Sieh,
a professor of geology at Caltech who has studied many earthquakes in
the region.
"How much time after the earthquake will they have before the tsunami
strikes? How big will the waves be? How far inland should they be
prepared to run? What areas are likely to suffer tsunami damage?" Sieh
asked.
"This paper is our first attempt to answer these important
questions."
A monster quake of magnitude 9.1 in December 2004 just off Sumatra's
coast caused a tsunami that crossed the Indian Ocean to Sri Lanka,
Thailand and even Africa's coast. More than 230,000 people died or
disappeared in a dozen countries in the devastation.
Sieh's team has reported on several potential quake zones, based on
measurements of the sea floor and known faults. The area is prone to
geologic activity and big quakes are frequent - and frequently fatal.
In this week's report, they said they studied samples of coral from
the islands that show how much previous quakes have lifted the sea
floor.
Offshore islands may shield Sumatra's city of Padang somewhat, but in
1797 the tsunami was reported to have carried a 200-ton English ship
into the town, they said.
"The population of Padang in 1797 and 1833 was a few thousand," Sieh
said in a statement.
"Now it is about 800,000, and most of it is within a few meters
(yards) of sea level. We hope that these initial results will help focus
educational efforts, emergency preparedness activities, and changes in
the basic infrastructure of cities and towns along the Sumatran coast."
Countries likely to be affected are installing warning systems. Last
week Thailand launched the first of 22 U.S.-made tsunami-detection
buoys, and the next buoy will go off Sumatra's coast.
WASHINGTON, Wednesday, Reuters
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