Repeat Indonesian Earthquake Likely
The following disturbing Brief Communication is found in tomorrow's Nature:
Last year's Indonesian earthquake has increased seismic hazard in the region. Following the massive loss of life caused by the Sumatra–Andaman earthquake in Indonesia and its tsunami, the possibility of a triggered earthquake on the contiguous Sunda trench subduction zone is a real concern. We have calculated the distributions of co-seismic stress on this zone, as well as on the neighbouring, vertical strike–slip Sumatra fault, and find an increase in stress on both structures that significantly boosts the already considerable earthquake hazard posed by them. In particular, the increased potential for a large subduction-zone event in this region, with the concomitant risk of another tsunami, makes the need for a tsunami warning system in the Indian Ocean all the more urgent.
The communication concludes that an earthquake in the range of 7.0-7.5 on the Northern Sumatra fault is an immediate threat. This is enough for a repeat tsunami. Thus, the call for a tsunami warning system in the letter.
Update: NPR has an interview with the paper's author.
Update: A follow-up quake actually happened:
GUNUNGSITOLI, Indonesia (Reuters) - More than 1,000 people were feared killed in a massive earthquake which hit a remote Indonesian island famed as a surfing paradise, reducing large parts of its main town to rubble.
The Indian Ocean epicenter of Monday night's 8.7 magnitude quake was just about 100 miles southeast of the upheaval three months ago which triggered a tsunami that left nearly 300,000 people dead or missing across Asia.