Asian tsunami could have made earthquake risk in

Indonesia worse

Earthquakes have been more common since the Asian Tsunami in

2004 that weakened fault lines around the world, according to a

new study.

By Louise Gray, Environment Correspondent

Published: 6:42PM BST 01 Oct 2009

The 2004 magnitude 9 earthquake beneath the ocean west of Sumatra in Indonesia was the second-largest

quake ever measured. It killed an estimated 230,000 people, mostly in Indonesia, Sri Lanka, India and

Thailand.

This week earthquakes of slightly lower magnitudes happened along the same line, killing up to 1,000 on the

island of Sumatra.

A recent US study found that the 2004 earthquake weakened fault lines around the world, including

California's San Andreas Fault.

The research, that was published in the journal Nature on the day the latest earthquake in Indonesia hit,

suggested the tsunami could have caused an increase in earthquakes around the world since.

"An unusually high number of magnitude 8 earthquakes occurred worldwide in 2005 and 2006," said study

co-author Fenglin Niu, associate professor of Earth science at Rice University. "There has been speculation

that these were somehow triggered by the Sumatran-Andaman earthquake that occurred on Dec. 26, 2004."

The study provided evidence for the first time that earthquakes like the 2004 tsunami could even affect fault

lines like the San Andreas Fault 5,000 miles away.

Separate research published in Nature also looked at the effect the Asian Tsunami had on the San Andreas

Fault.

The study by the Carnegie Institute in Washington measured how seismic waves from the 2004 quake

weakened other fault lines and may help to predict earthquakes in the future.