Giant Quake Predicted to Strike Sumatra Within Decades

Research has led EOS Director Kerry Sieh and his colleagues to predict that an earthquake of up to magnitude 8.8 can be expected off the western coast of Sumatra within a few decades. Scientific evidence points to a probable rupture somewhere along a 400-km (250-mile) section of an undersea subduction fault line, running parallel to Sumatra, known as the Sunda megathrust.

The section expected to rupture lies beneath the Mentawai Islands, so Padang in particular would be hard hit. The historical record suggests that a giant quake occurs in this area roughly about every two centuries, accompanied by a cluster of other sizable quakes. A similar pattern of activity seems to be playing out now, with several large quakes in the area over the past decade as part of the latest cycle. Because the megathrust segment below Mentawai hasn’t ruptured for about 175 years, the accumulated stress in interlocked sections of the underlying megathrust means the next earthquake, when it comes, will almost certainly be a powerful one – nearly rivaling, perhaps, the deadly Aceh-Andaman Sea earthquake and tsunami of December 2004.

Media Coverage:

• Next Big One Will Strike Sumatra Within Decades, The Straits Times, 14 Oct 2009
  
• Geologist Narrows Down Location of Southeast Asia's Next Big Earthquake, The Straits Times, 12 Aug 2009
  
• Straits Times Razor TV: Interview with Prof Kerry Sieh, 15 Oct 2009
  

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