AGARTALA / GUWAHATI, July 22 (TIWN): Agartala, Guwahati, Shillong are the three Northeast Indian cities at highest risk of being devastated by an earthquake of 8 to 9 magnitde in Richter scale, also 36 other cities in areas prone to earthquakes, according to Indian government data. Guwahati and Agartala fall in what is called “very severe intensity zone”, or zone V, the highest-risk earthquake zone. 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. Tripura’s earthquake preparation almost NIL as State Govt failed to follow Centre’s directives on disaster management. State administration and concerned departments are telling that they arranged mock drills once in few years to aware the people about the preventive measures to be taken at the time of disaster, but all these insufficient trainings may go into vain as most of these buildings may completely collapse at the time of earthquake. "The Indo-Bumese arc, the north-south oriented mountain chain, passes through Bangladesh and a major portion of India, Tripura, NE region 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," informed by Vineet K. Gahalaut, Director of the National Centre for Seismology under the Ministry of Earth Sciences.

Eight cities, including Delhi, fall in the “severe intensity zone” or zone IV, according to a seismic zoning map issued by the Bureau of Indian Standards and quoted in a National Disaster Management (NDM) report. The other 30 cities fall in the “moderate intensity zone”, or zone III.

“India has highly populous cities, including the national capital of New Delhi, located in zones of high seismic risk,” said the report. “Typically, the majority of the constructions in these cities are not earthquake resistant. Thus any earthquake striking in one of these cities would turn into a major disaster.”

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.

"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  media, 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.

About 50 million years ago, India — then an island that had previously broken off from a supercontinent called Gondwana, a name still used for what is now Chhattisgarh — slammed into the Eurasian mainland, creating the Himalayas as it collided.

All land on earth rides on “plates”, which glide on the mantle, a rocky inner layer. The Indian plate continues to grind into the Eurasian plate, and as it does, the Himalayas and north India are on shaky ground.

India pushes northeast into Asia at roughly 5 cm every year, causing subterranean stresses that are released in the form of earthquakes every now and then.

Vulnerable zones are monitored, but prediction is impossible

An array of sensors in India and abroad monitor plate activity, but it is impossible to predict an earthquake, as many tweets and Whatsapp messages after the Nepal temblor appeared to indicate

What is available is data on areas of specific vulnerability.

Gujarat and Uttar Pradesh appear to be the most vulnerable states, with six cities each in earthquake-prone zones. Both the states have one city each under zone IV and five cities marked under zone III. Maharashtra is next with four cities in zone III.

The Bureau of Indian Standards (IS-1893 – part – 1: 2002), based on scientific inputs from a number of agencies, including earthquake data supplied by Indian Meteorological Department (IMD), has grouped India into four seismic zones, II, III, IV and V.

The Modified Mercalli (MM) intensity scale, which measures the impact of earthquakes on the surface of the earth, is broadly associated with India’s earthquake zones.

India has 42 digital seismograph stations to measure earthquake magnitude and monitor earthquake activity, operated by the Ministry of Earth Sciences. As many as 78 new digital seismographs are likely to be installed during 2015-16.

"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.

Tripura always on the high risk of massive earthquake as it is situated on seismic zone-¬V, also has probability of earthquakes measuring more than 8 magnitude on richter scale.

Though, Tripura  government has already identified 2,000 vulnerable buildings including Ujjayanta Palace, Raj Bhavan, Neer Mahal, a lake palace built by Tripura’s last king Bir Bikram Kishore Manikya in 1933, MBB College and a large number of school buildings, but no proper preventive measure was adopted by the state government till date.

Besides, several high storied buildings are being constructed everyday flaunting rules which are a real threat at the time of earthquake.

Despite these findings, at the time while the state government needs to take preventive measures, it is busy in scams and investing money in other illegal construction businesses.