Tsunami secrets in coral life

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A TEAM of geologists from the Indian Institute of Science, Bengaluru, is studying coral reefs of the Andaman & Nicobar Islands to understand how previous tsunami strikes impacted the sea floor and the coastline.
Into its last phase, the four-year project hopes to draw certain inferences that would eventually help frame a manual for rescue operations.
“Apart from studying corals, we are also digging out tsunami deposits along the Andaman coast,” said Dr C.P. Rajendran, research scientist at the Centre for Earth Sciences at IISc. “We are tracing changes that tsunami waves scripted on the topography.”
“In many areas, we could reach the last point to which surging waters reached,” he added. “This stretch is being dug out for tsunami deposits.”
Receding waves leave tons of debris along the impact zone that lie buried under the carpet of fresh sand deposits. “Our attempt is to calculate the age of this debris through carbon dating for a peep into the past,” he said over phone from Andamans,
``We are also studying the coral reefs,” said Mr Rajendran. “A close examination of the ocean floor will tell you that it is very uneven. We find that corals of almost the same age live on shelves separated by many inches underlining the fact that an even ground either moved up or subsided under the impact of a quake.”
Mr Rajendran said that through a series of studies, the team had been able to quantify recurrence and get some idea about the elevation of ocean floor.
Another area under study is the Kaveripatnam coast where the IISc team has traced destruction caused to early settlements. Studies have revealed how colonies along the coast were struck by tsunami or a similar-phenomenon in the past.
“This study is only to understand how far huge waves can travel into the mainland,” said Mr Rajendran. “Maybe it will help us draw up a line of last impact beyond which people could be shifted.”
The study will be completed by December, which marks the seventh anniversary of the tsunami that licked away thousands of lives along Indian coasts.