Regional geology and tectonics of the Southern India

Recent and contemporary tectonic unrest at the coast of Gulf of Mannar, Tamil Nadu, India

The southernmost segment of the Coromandel Coast of Hindustan Peninsula, the shore of the Gulf of Mannar facing Sri Lanka, has been considered seismically quiet and inactive by many researchers. This, among other reasons, led in early 2000s to the decision of putting an atomic power plant in Kudankulam. Indeed, not a single notable seismic event has been felt in the area all along, and the geological structure, at first sight, does not show any evidence of ongoing rebuilding.

Nevertheless, careful examination of regional geology shows some oddities like rapid development of young sand dunes, at times rather far from the current coastline, unusual outcrops of bedrock at the beaches, disturbances in stratigraphic record and so forth, which do point at some recent and contemporary tectonic processes operating steadily but smoothly, without earthquakes so far. To explain them, a model of wrench dislocations was proposed by Longhinos that seems to have accounted for all the evidence of tectonic activity, but to verify it an impartial method is needed that would bring the theory and the data into a self-consistent framework and show how well the theoretical implications are supported by real data. Such framework is being developed by the event bush method in collaboration with Biju Longhinos, University College Trivandrum, India, and Vladimir Anokhin, Institute of Limnology, Russian Academy of Sciences.

Summit caldera lake at Tianchi Volcano, China/North Korea. Photo by Cyril Pshenichny