Scientists say they have discovered evidence of a giant tsunami in the Indian Ocean some 600 years ago that is comparable in size to the one that killed an estimated 230,000 people in the same area in 2004.
Studies published this week in the journal Nature document evidence in sand deposits in Indonesia and Thailand that indicate a massive tsunami took place on those coastlines sometime between 1290 and 1450. The researchers carbon-dated soil samples using organic material found under the sand deposits.
The experts said the findings indicate that tsunamis of such magnitude occur in the Indian Ocean only every 600 to 700 years. But they say people still need to be educated about tsunami warning signs to guard against smaller such events.
The scientists noted that one Indonesian island, Simeulue Island, had very few tsunami deaths in 2004 because islanders still tell the story of a 1907 tsunami that killed many people.