Wednesday, March 24, 2010

A confused tale of a disappeared island

In a wonderfully confusing tale, an island in the Bengal Sea has disappeared.

The world community doesn't know what to make of it. Some are blaming its disappearance on climate change and rising sea levels.

There is no doubt that sea levels are rising, but the death of New Moore Island can't reasonably be blamed directly on that. (The ephemeral isle is known in Bangladesh as South Talpatti, and to some Indians as Purbasha.)

The island reportedly was six feet above sea level a couple of decades ago, and even at the highest estimated rate of rise, it should only be down to 5-foot-10 or 11 today. But some scientists are happy to blame sea level changes, which reportedly have been troublesome in the Bay of Bengal.

The BBC quotes Professor Sugata Hazra of the School of Oceanographic Studies at Jadavpur University in Calcutta, who said his own research indicates sea levels have been rising much faster since the turn of the century than in years earlier.

And it is reported elsewhere that New Moore only popped above the waves in the 1970s, and it was never much of a land mass, although India and Bangladesh have been fighting over title to it. But other sources suggest it may have existed for decades earlier.

Apparently its appearance followed a tropical rotating storm, Cyclone Bhola of 1970, suggesting it may be, at best, an emergent sand bar, like ones that occur in Kane'ohe Bay and elsewhere in Hawai'i. It lies roughly in the middle of a channel between India and Bangladesh.

Some references call New Moore a rock island, but that seems unlikely. And clarity isn't helped by the fact that none of the photos that accompany the story is actually of the disputed island.

Clearly there's something strange going on in the Bay of Bengal, where another island, Lohachara, sank in 1996, and the island of Ghoramara is half under. Our guess: that sea level changes are indirectly to blame, by changing erosion patterns that can cause delta islands like these to quickly disappear.

© Jan TenBruggencate 2010

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