Abstract
After lying dormant for about a thousand years, sudden slippage of a 1600-km long section of the Sunda megathrust fault caused uplift of the seafloor between Aceh and Myanmar, resulting in a great earthquake and the horrific Indian Ocean tsunami of 2004. Three months later and just to the south, sudden slippage of a 350-km length of the megathrust beneath Simeulue and Nias islands caused another destructive great earthquake and lesser tsunami. Because it takes centuries for tectonic strains to build up again after such big earthquakes, these two events are unlikely to recur within the next hundred years. Farther south, however, offshore West Sumatra and Bengkulu provinces, another great earthquake and tsunami will likely occur within the next few decades. We are trying to characterize that future earthquake and tsunami, to encourage and to focus preparations for and mitigation of the coming disaster. Similar efforts need to be initiated throughout much of south and southeast Asia, if the disastrous effects of future large earthquakes and tsunamis are to be mitigated.