I am attaching a research article that may be useful for the Tamil Nadu history-buffs in this forum.
Geoarchaeological evidence of a Chola-period Tsunami from an ancient port at Kaveripattinam on the Southeastern coast of India” authored by C. P. Rajendran, Kusala Rajendran, S. Srinivasalu, Vanessa Andrade, P. Aravazhi and Jaishri Sanwal in Geoarchaeology: An International Journal, 26(6):867-887 (2011).
The authors (geologists, and one ASI archeologist) examined the in land region near the coast of Kaveripattinam at 21 sites, and conclude based on well-established scientific dating techniques that about 1000 years ago there was a major tsunami that came ashore at Puhar, and the dating concurs with measurements made at other Indian Ocean sites. The authors also suggest (not prove) that the tsunami destroyed the port city, and as a consequence the port city did not recover. The authors also quote temple inscriptions (more than one) that suggest the occurrence of the ancient tsunami.
In any case –with any research article, we should question both the interpretations and the arguments made in the article, not the data. We should take the findings as the best knowledge we have available at the present time, and that it may change in due course of time with new findings.