“In recent earthquakes, buildings have acted as weapons of mass destruction.”

This is what renowned US-based seismologist Dr Roger Bilham famously observed during a visit to the mega-quake-hit Haiti last year.

Closer home, his words ring a bell in the context of the M6.8 quake (magnitude of 6.8 on the Richter scale) that jolted Sikkim in the Himalayas on Sunday evening.

MOST VULNERABLE

Cities in third world countries are most vulnerable because they often have widespread sub-standard housing and a weak infrastructure.

Sikkim State falls in Seismic Zone IV of the earthquake hazard map of India, and this corresponds to High Damage Risk Zone.

Seismic activity along the Himalayan arc is due to the thrusting action of Indian plate beneath the Eurasian plate, experts say.

The India plate converges with Eurasia at a rate of approximately 46 mm/year towards the north-northeast and this has resulted in the uplift of the Himalayas, the world's tallest mountain range.

Risk governance

Large destructive earthquakes have occurred across the arc. Research as well as instrumentation indicates the possibility of large earthquake in the near future.

‘Seismic deficient' buildings and infrastructure, which means those which are not built as per the earthquake code of practice in quake-prone areas, combined with poor risk governance, collateral impacts (landslide, liquefaction, amplification across ridge, mass movement, etc) and inaccessibility are primarily responsible for deaths and injuries.

Damage records and observations from neighbouring States and countries indicate the vulnerability of the built environment.

PREVENTIVE ACTION

Buildings and critical infrastructure such as communication, emergency centres, power, hospitals and transport, among others, across the seismic prone region will require a phased assessment and strengthening/retrofitting so that they can survive and remain functional in case a future event occurs in the region.

While earthshaking cannot be prevented, life loss and damage can always be minimised with thoughtful and preventive action.

Current trend in climate change related initiatives globally, has somewhat reduced the interest of institutions to work in earthquake risk reduction initiatives although they are equally important, a research paper by the Bangkok-based Asian Disaster Preparedness Centre rued.

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