Damage control: On the Tibet earthquake
Adherence to existing regulations can limit the impact of earthquakes
This week, an early-morning earthquake in Tibet of magnitude 7.1 and originating at a depth of 10 km has reportedly claimed at least 100 lives and damaged buildings and houses. The tremors from the quake were felt in Nepal as well as parts of Bihar and even New Delhi, thousands of kilometres away. The main earthquake was followed by at least two aftershocks. If the epicentre had been located closer to India, the damage could have been manifold. Earthquakes in the Himalayas evoke a special kind of dread in the country. Memories of two deadly quakes in Nepal in April and May of 2015 that killed at least 9,000 and caused incalculable damage still bubble up. The tectonic plates are the gigantic shards into which Earth is broken up. Layered on them are the continents and the seas. These plates are constantly in motion — colliding with, diverging with, or sliding past one another. The Indian plate collided with the Eurasian plate and the crust tilted upwards, creating the Himalayas. The fractured zones along which they interact create the fault lines where earthquakes occur. By studying these faults and the pattern of past earthquakes, seismologists can estimate how much latent energy at these fault lines, which can run thousands of miles, has been released and how much of it still resides in them.
Scientists have long warned of a massive, overdue earthquake in the Garhwal-Kumaon range because of what is known about the pattern of quakes in the region. The records of the last 300 years suggest that those that have occurred have not released all the pent-up energy and that is why there is a broad consensus among experts that an 8-magnitude temblor is overdue. Unfortunately, predicting the day and time is outside the ambit of current science. Thus, the best we can hope for is insulation against the projected damage. It is in this context that infrastructure development in the Himalayan region must be viewed. While several of these projects are intended to smooth the movement of people and goods, the recurrent landslides and glacial lake outbursts that wash away dams, hydropower projects, and roads serve as a constant reminder of the inherent fragility of the region. Every form of infrastructure in the region — power plant or dam — must take into account the imminence of a major earthquake and the associated costs factored into planning. Adhering to already existing building codes, not only in the Himalayas but in the surrounding Indo-Gangetic plains, can go a long way in limiting the inevitable damage.