If statistical findings and historical evidences are to be believed, devastating Indian Ocean Tsunami is likely to hit the region again not before 2604. Following the Indian Ocean tsunami of 2004, research was carried out that came forward with the fact that it was not the first time in 2004 that world has faced with such destructive tsunami.

They said, such tsunami rotates in every 600 years! And then, it becomes 2604 when the subcontinent may once again face tsunami with considerable devastating power.

In 2004, the Indian Ocean tsunami took more than 200,000 human lives. Scientists have found evidences of such killer-tsunamis even before 2004. According to a group studying the tsunami, Thailand and Indonesia had witnessed last massive tsunami of similar magnitude about 600 years ago, between 1300 and 1400 AD; though, exact scale of that tsunami is yet to be confirmed from other dependable sources. Also, the research has established a periodicity of occurring tsunami in the Indian Ocean region to about 600-700 years, thereby erecting a statistical standard for estimating possibility of future tsunamis.

In the past 1,200 years, there were three tsunamis, said Karin Monecke, former post-doctoral geologist of Kent State University in Aceh, Indonesia, and team leader for one of the current tsunami research teams. Each of the groups researching on the tsunami have completed their fieldworks during 2006 and 2007, and have collected more than one hundred sediment cores just to discover evidences of occurring several tsunamis during the last 2,800 years.

In general, an earthquake measuring 7 or more triggers a massive tsunami. In December 2004, the magnitude of earthquake was 9.2 and the resulted tsunami had created waves of 20 metres, 30 metres, 35 metres, and even higher heights. As a result of each tsunami, sand sheets get deposited under layers of coastal peat, some of them get preserved centuries together without any effect from human beings. These preserved sand sheets form the basis of studying tsunami histories. The researching teams have undertaken drilling operations to find the sedimentary treasures. Following the carbon-dating technique on organic debris that are collected from just below the sand sheets, scientists have tried to find out the periods of creation of those sand sheets and the tsunamis.