The entire Himalayan belt is seismically very active and during a short span of 53 years between 1897 and 1950, four major earthquakes, (Shillong -1897, Kangra -1905, Bihar-Nepal -1934 and Assam -1950) exceeding magnitude 8 on the Richter scale occurred in the region causing vast devastation.
"No such earthquake has occurred since 1950. Studies indicate that enough strains have accumulated to generate magnitude 8 or larger earthquakes in the Himalayan region. If an earthquake of magnitude 8 occurs in the Himalayan states, eight to nine lakh people may lose their lives," the NDMA vice-chief told PTI.
Reddy said when and where such an earthquake would occur is not known and therefore, the best approach to face such an eventuality was to work for developing an earthquake-resilient society.
Towards this goal, the NDMA has recently undertaken an exercise to develop a scenario of what would happen if a quake of magnitude 8 on the Richter scale occurs at a certain location, he said.
Earlier, an exercise was undertaken for such a quake occurring some 200 km away from Delhi, for the National Capital Region. Subsequently, NDMA undertook a more detailed 'Multi-State Earthquake Scenario' project for a hypothetical magnitude 8 earthquake occurring in Mandi in Himachal Pradesh.
"If an earthquake of magnitude 8 or more occurs in a place like Mandi, at least 20,000 people may die in a city like Chandigarh, the nearest biggest urban settlement," Reddy said.
NDMA is now proposing to take up an exercise for the northeastern region on how to face a situation if there is a repeat of the Shillong earthquake of 1897.
The Shillong earthquake had ruined masonry buildings over a large area and was felt from Myanmar to Delhi.
A revisit of that tremor in the present day context is likely to present a very damaging scenario due to migration of population to cities and the change in building typology in the region vis-a-vis traditional houses, and buildings have been replaced by "un-engineered concrete structures," an NDMA study says.
A scientifically-developed earthquake scenario for the Shillong earthquake will bring out its anticipated impact on lives and property, and forewarn on the challenges to be met.
The project will undertake a scientific assessment of the vulnerability of the region to the impact of such an earthquake to facilitate capacity building and multi-state coordinated preparedness for disaster management.
"We have found that if 1897 Shillong earthquake occurs today, the loss of lives could be six lakh in Assam alone," Reddy said.