By Sahana Ghosh
Kolkata, July 22 (IANS) Efforts are on by Indian seismologists and geologists to jointly carry out studies with Bangladesh and Myanmar and form a common geodetic network to verify fresh data and sort out discrepancies over earthquake-related research in the region.
In a recent paper in Nature Geoscience, a group of scientists published new evidence of the increasing strain building beneath Bangladesh, where two tectonic plates underlie the vast delta of the Ganges and Brahmaputra rivers, one of the most densely populated regions in the world.
They estimate that at least 140 million people in the region could be affected if the boundary ruptures.
However, a section of Indian experts has expressed reservations over some of the details discussed in the paper.
"The Indo-Bumese arc, the north-south oriented mountain chain, passes through Bangladesh and a major portion of India and Myanmar. When the countries work in isolation, things fall apart. The idea is to let all the countries join together. There is some discrepancy in some of the numbers. So we feel let's sort it out together," Vineet K. Gahalaut, Director of the National Centre for Seismology under the Ministry of Earth Sciences, told IANS.
"We will design a common network and plan in such a way that we can answer many questions related to the plate margin," said Gahalaut, who is aware of the latest publication.
In the paper, lead author Michael Steckler, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory in the US, claims Bangladesh and its neighbourhood including India may be hit by a huge earthquake -- although not imminent -- that could reach a magnitude of nine on the Richter scale.
Southern Asia is composed of three major plates: the Indian Plate, the Australian Plate and the Sundaland Plate. The Indian and Sundaland plates abut in Myanmar.
Steckler and colleagues claim 10 years of data show that eastern Bangladesh and a bit of eastern India are pushing diagonally into western Myanmar at a rapid rate -- 46 millimetres, or about 1.8 inches, per year.
But Gahalaut and his colleagues were of the view that "the India-Sunderland motion is about 36 mm/year."
This "extra 10 mm/year" is "bothering a section of Indian researchers, including Gahalaut and Bhaskar Kundu of Department of Earth & Atmospheric Sciences, National Institute of Technology, Rourkela.
Kundu said he "does not completely agree" with the findings.
"Our work says that the plate boundary is predominantly aseismic in the Indo-Burmese Arc region, northeast India and such aseismic motion on the plate boundary fault significantly lowers the seismic hazards," Kundu told IANS, adding it is difficult to justify the findings of the new paper based on the models used.
According to Gahalaut, the 46 mm/year number needs to be further confirmed.
"We need to better constrain it by taking more measurements from Myanmar. This is the reason we are planning a common seismological and geodetic network which will span the entire Indo-Burmese arc," he said.
The idea is that scientists will approach their own governments and get funding, explained Gahalaut, who is spearheading the collaboration on the Indian side.
This would also enhance data-sharing, including the results, he said, stressing that at this point in time, real-time monitoring is not required.
"There is no doubt that a large magnitude earthquake occurred in the coastal regions of (what is now) Myanmar and Bangladesh in 1762, known as Arakan earthquake. So this is true that this region is susceptible to large earthquakes. But how big it could be is a bigger question," contended Gahalaut.
(Sahana Ghosh can be contacted at sahana.g@ians.in)
