Tsunami threat hangs over Bay of Bengal

~ Contributed by Manish Mathur ~

An earthquake could one day strike the northern Bay of Bengal, triggering a tsunami and threatening at least a million people's lives. This contradicts the prevailing idea that the region is relatively safe from such a threat.

Phil Cummins of Geoscience Australia in Canberra has reviewed GPS measurements and says the boundary between the Indian and south-east Asian tectonic plates does not cut through Burma, as previously thought, but probably lies up to 200 kilometres off the coast. This increases the quake risk because the plates are pushing harder against each other. Such a quake could cause a tsunami more forceful than the one that devastated Indonesia and Thailand in 2004.

Cummins combined geophysical data relating to a northern extension of the same fracture linked to the Sumatra-Andaman earthquake and tsunami of 2004 with 18th century British archives to argue that a seismogenic zone lies underneath the bay. An archive from 1763 which Cummins studied suggests that a large offshore earthquake may have occurred in the region in 1762. It mentions that in Dhaka, the river rose and hundreds of large country boats were driven ashore or lost.

But Cummins has cautioned that it is still not clear whether this was due to a wave from the sea or a change in land level. Earthquakes are unpredictable with present-day science. However, the data suggests that it may be over 200 years before a large earthquake occurs in the region, Cummins said. Read the full article in the current issue of Nature. {Image has been sourced from the Internet}