Preparedness and mitigation systems for Asian Tsunami-type hazards

Abstract

The devastating impact of the 26 December 2004 Indian Ocean tsunami (also known as the Asian tsunami) on coastal communities has been widely reported in the media. The tsunami has so traumatized the public that governments are under pressure to spend vast amounts of money for warning and protective measures against the tsunamis. It should not, however, be forgotten that tsunamis are comparatively rare events, and consequently the expenditure on preparedness should be commensurate with the probability of risk. It is safe to state that the probability of an equally powerful tsunami being triggered at around the same location in the next few decades is low for two reasons: (1) The repeat time for Sumatran-type subduction zone earthquakes is typically 200-300 years; and (2) the tsunami of 26 December was rendered so powerful because of the sudden release of the stress energy that accumulated over a long period of time in the area. This does not, however, preclude less powerful tsunamis from being set off in the future at this or other locations in the Sumatran belt.