Manipur earthquake. Another wake-up call for India

By PG Dhar Chakrabarti:

The tremor that shook the Northeastern states and West Bengal on January 4 must be treated as an urgent wake-up call. The earthquake, which had its epicentre at Tamenglong in Manipur, is the 20th such quake of magnitude 6 or higher on the Richter Scale to hit the region in the past century or so. It only re-confirms that the seismic faultlines of the eastern Himalayas are hyper-active. At least two of these earthquakes — the great Assam earthquakes of 1897 and 1950 — had crossed magnitude 8.5 and above — causing widespread devastation in the region. Scientists have been warning that the ‘return period’ of such big earthquake in the eastern Himalayas is long overdue.

Harsh Gupta, former director of the National Geophysical Research Institute, Hyderabad, is more specific in his warning: “Moderate magnitude to great earthquakes in the northeast India region is found to be preceded, generally, by well defined earthquake swarms and quiescence periods. On the basis of earthquake swarm and quiescence period, an area bound by 21 deg N and 25½ deg N latitude and 93 deg E and 96 deg E longitude is identified to be the site of a possible future earthquake of M 8 + 1- ½ with a focal depth of 100 +/-40 km. This earthquake should occur any time from now onwards.”

The impact of such a mega earthquake would be many times more devastating than in the past. In 1951, the population of the region was 8 million, today it has crossed 50 million. The Northeast had hardly any built-up modern infrastructure before the Independence; Today it has a network of roads, bridges, railways, airports, etc. It has more than a million residential and commercial buildings, but many of those don’t comply with the specifications of earthquake-resistant designs and processes.
The recent earthquake in Manipur has once again demonstrated that even many of the newly constructed buildings are not able to withstand the 6.7 quake. So the impact of an 8+ on the Richter Scale tremor on such and other older structures would be devastating.

The National Institute of Disaster Management, in collaboration with the United States Geological Service, had developed a scenario of the 1950 earthquake recurring in 2011 and the findings were horrifying. Based on these, a roadmap was developed for earthquake risk mitigation in the North East, but implementation has been dismal.

Earlier in 2007 the National Disaster Management Authority (NDMA) had released its comprehensive guidelines on management of earthquakes on ‘six pillars of seismic safety’ — earthquake-resistant constructions, retrofitting of lifeline structures, regulation and enforcement, awareness and preparedness, capacity development and response. The activities to be taken up under each of these six pillars were to be implemented in two phases, the first completing in June 2009 and the second phase in January 2010. None of these activities have been completed even remotely.
The Manipur earthquake must push the state governments, the NDMA, the ministry of home affairs and the ministry for development of North Eastern Region to get their together so that we are not sleeping when an earthquake strikes again.

PG Dhar Chakrabarti is former director of the National Institute of Disaster Management, and now Distinguished Fellow at TERI. The views expressed are personal.

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