The birth and death of an island in the Bay of Bengal

By Nils-Axel Mörner

In 1970, the Bay of Bengal was struck by the very powerful Bhola Cyclone. This was a truly disastrous event with a casualty in the order of 500,000 people. This event also caused severe coastal damage. Vast quantities of sediment were set in suspension, and there were significant turbidity flows.

At the boarder between India and Bangladesh, these sediments transported down the river accumulated in a muddy sand-bar that grew into an island. This newly-created islandcame to be called South Talpatti or New Moore Island.

There is nothing strange in this. Islands come and go for local reasons triggered by sudden events and longer-term dynamic forces.

On 25 March, 2010, it was suddenly announced that the island had disappeared. Many, including scientists (for example Sugata Hazra, professor in oceanographyat Jadavpur University in Calcutta), took the island’s disappearance as an expression of a rapidly rising sea level.

The fact, however, is that it has nothing to do with any global sea level rise, but is attributable to local dynamic factors operating in this part of the Bay of Bengal.

So, the Island of South Talpatti (New Moor Island) was born in 1970 and killed in 2010. The island had a short lifetime of only 40 years. The ultimate cause of its birth was cyclone damage. The cause of its death is likely to be local dynamic influences operating in this part of the huge delta, and it is surely not an effect of a rapid global sea-level rise.

Over the last 40 years we record a virtually fully stable eustatic sea level, even in the Sundarban delta of Bangladesh. The disappearance of the island is by no means a sign of global sea-level rise.