The September 2009 earthquake in Indonesia did not significantly relax the threat of a high-magnitude tsunami-generating earthquake in the region, reports a study online this week in Nature Geoscience. Stress on this segment of the fault has been accumulating for about 200 years, suggesting the need for urgent action.
John McCloskey and colleagues investigated the stress released during the September 2009 earthquake of magnitude 7.6 near the Indonesian city of Padang, which is located on Sumatra near Siberut. They found that the quake did not rupture the section of the Sunda megathrust along the coast of Sumatra that had remained unbroken by a series of earthquakes after the 2004 quake and tsunami. The danger of strong shaking and the potential for tsunami generation as forecast earlier therefore is therefore still immanent.