Washington, Jan 29 : A new review of tsunami hazards has revealed that the catastrophe that happened in the Indian Ocean in 2004 was not the worst yet and that an even bigger tsunami might possibly occur in the future.
Costas Synolakis, director of the University of Southern California Tsunami Research Center and Emile Okal of Northwestern University carried out the review.
As part of their research, the authors of the study evaluated all known potential tsunami-generating sources in the vast area between Africa, Asia, Australia and Antarctica, and then calculated the impact of the tsunamis they can generate, should they rupture.
The researchers examined eight scenarios, two along Southern Sumatra (in Indonesia), two in the North Andaman segment of the Sumatra Subduction Zone, two sources along the Makran Subduction Zone (south of western Pakistan) and two sources south of Java.
According to the review, the impact in the mid-ocean Maldives Islands from all scenarios appears to be similar or less than what was observed in 2004 - however the low-lying structure of the islands makes them more difficult to evacuate than other risk sites.
The impact in Madagascar and the Mascarene Islands (Mauritius, Rodrigues and Reunion) and the Seychelles could be far greater than in 2004, particularly from earthquakes in Southern Sumatra and in South Java. Madagascar is found particularly vulnerable from South Sumatran tsunamis. Africa suffered in excess of 300 deaths in 2004, 300 of them in Somalia. Its east coast is vulnerable from south Sumatran tsunamis and in particular, Somalia remains at high risk due to the focusing effect of the Maldives ridge. Also, The Comoro islands located between Tanzania and Madagascar would probably be affected more severely than in 2004.
The Strait of Malacca area also appears more vulnerable than in 2004, from earthquakes in the North Andaman.
Another area which might have a greater impact would caused by large under-sea earthquakes in south Java, which would generate substantial levels of destruction in Northern Australia, despite the sparse level of development there.
All these factors make it important for the implementation of effective tsunami warning systems.
"It is quite clear that a tested and true tsunami early warning system as now works in the Pacific by the Pacific Tsunami Warning Center needs to be urgently implemented in the Indian Ocean," said Synolakis.
"This system should include hundreds of pre-computed detailed scenarios of inundation for all Indian Ocean nations to facilitate emergency planning for evacuation should any of these scenarios materialize," he added.