Nepal is reeling under the effects of the worst earthquake in more than 80 years. Nepal’s Prime Minister Suhsil Koirala has warned that the death toll in the magnitude 7.8 earthquake, which struck an area between the capital Kathmandu and the city of Pokhara, could touch 10,000. Hopes of further rescues are fading, and the focus is now switching to relief. This major disaster has affected even Nepal’s neighbors – India, China, Bhutan, Bangladesh, Myanmar and Pakistan – with the death toll in India crossing 60 and that in China reaching 25.
The bigger worry at this point in time is that the aftershocks continue to jolt the Himalayan region. The magnitude 6.7 tremor on the following day created absolute alarm among the people of Nepal, forcing them to leave all the buildings and seek shelter in open spaces and tents as well as hampering rescue operations to a great extent. A vast majority of the old buildings (including heritage sites) have collapsed and many new ones have developed cracks. Avalanches triggered by the earthquake and the aftershocks on Mount Everest have taken at least 18 lives, including that of foreigners. Seismological data has revealed that Kathmandu could have moved about 10 feet southward. International aid from countries across the world, particularly India, has poured in to assist Nepal in this desperate situation.
What cannot be denied is the fact that Nepal is not just a victim of geological fault lines but also poor socioeconomic and physical infrastructure that leaves the country’s population highly vulnerable to such geological disasters. While Nepal’s vulnerability is definitely the focus of attention at this point in time, the other countries of the Himalayan region, including India, are equally at risk.
Geological Factors and Infrastructure Woes
Nepal has had a history of powerful earthquakes over the last millennium, according to geological record dating back to 1100. In fact, many of those heritage structures in Kathmandu’s famous Durbar Square had previously been subject to renovation and reconstruction, owing to damages incurred by centuries of earthquakes. Even though some of the really old structures such as the Pashupatinath temple withstood the shocks with minor damages, the spate of the not-so-lucky post-17th century structures speaks volumes about the shoddy construction practices that are still being followed and gross negligence towards the lessons of history.
The earthquake had been anticipated for quite some time, especially within the geological community. Nepal sits right above the most active and hazardous seismic fault zone in the world. If one goes back several million years, the world comprised two lithospheric units (supercontinents of Laurasia in the north and Gondwana in the south) that were separated by a long narrow ocean called the Tethys. Because of concomitant tectonic activities, both these blocks started to rupture from within. This gave rise to the continents of the present day – after they started breaking apart and drifting away from one another. Initially, the Indo-Australian plate split from the Gondwana landmass, and then later the Indian sub-plate further broke away (off Madagascar) and drifted northwards to collide with the gigantic Eurasian plate.
The subsequent collision gave rise to the Himalayan mountain system – the youngest and highest in the world. The Himalayas and the adjoining Tibetan Plateau in the north were thus formed as a result of the folding and uplifting of the Tethys seabed. The more the Indian plate slides underneath the Eurasian plate (which it continues to do so), the higher the Himalayas will grow and greater will be the chances of earthquakes occurring in the region. The current earthquake, along with the 2005 Kashmir earthquake, are testimonies to the continuing subduction of the dense Indian plate beneath the Eurasian plate. This phenomenon renders excess strain on the lower crustal rocks, resulting in their deformation and eventual collapse. The seismic waves generated during the quake use these weak spots as exit routes, resulting in aftershocks that ensue the major quake. These tremors and aftershocks can trigger potential landslides and mud-slips (when accompanied by rain) in a fragile sedimentary ecosystem like the Terai region (lowlands and foothills along the Nepal-Bihar belt). Above the snowline, this could however translate into avalanches, like the one that occurred on the Everest trekking trail.
Taking stock of the recent earthquakes along the Himalayan thrust belt, it is pertinent to point out the aftereffects of such quakes on the nearby Indo-Gangetic plains. The floodplains of the Ganges and its tributaries are rich in fine silt and alluvium, formed as a result of fluvial erosion of the clastic sedimentary rocks that pervade the region. During earthquakes, these rocks and alluvium that make up the riverbeds undergo a process of liquefaction. Accordingly, the already saturated soil starts behaving like a fluid in response to the induced stress. A classic example of earthquake-induced liquefaction is the 1934 Nepal-Bihar earthquake (magnitude 8.2), which took more than 10,000 lives and caused widespread destruction of property – mainly on account of the spewing up of river mud. Had the current earthquake exceeded 8 on the Richter scale, liquefaction-induced destruction would have obliterated quite a number of urban and sub-urban dwellings across the floodplains and riverine valleys (along foothills) in the Indian downstream state of Bihar.
Need for Risk Reduction Strategies
Earthquakes cannot be predicted; only the probability of their occurrence can be estimated. Therefore, greater emphasis should be placed on geotechnical engineering and earthquake-resistant construction designs-cum-techniques to minimize damage to life and property. In this exercise, “hazard and risk zoning” should be given a priority, such as to avoid areas with high chances of soil leaching and liquefaction. The population residing in the region also needs to be apprised of its vulnerability and disaster mitigation measures that could be implemented in the event of a similarly massive earthquake – given that the region is likely to experience more powerful quakes in the future.
This disaster also highlights the need for cooperation among Himalayan countries in addressing the impending danger of more earthquakes and the potential devastation they could unleash. The Indian Government has for instance laid down a roadmap for a National Mission for Sustaining Himalayan Ecosystem as a part of its National Action Plan on Climate Change. However, India needs to go beyond “climate policy” on the Himalayan front and look into these aspects of environmental security as well as set up a sub-regional arrangement to pool in disaster management resources. When the problems and interests are shared, the solutions should be shared too.
We live in an era of complete “uncertainty” about the environment we inhabit and exploit. As the number of humanitarian disasters across the globe rises, the need for increased focus on disaster risk reduction measures becomes critical, particularly in the Himalayan region. While rescue and relief gains pace in Nepal, future planning (mainly in infrastructure) should take into consideration environmental/geological risk assessment and management – an undervalued part of the entire environmental security discourse.
Dhanasree Jayaram is a Ph.D. Candidate in the Department of Geopolitics and International Relations and aProject Associate in the Manipal Advanced Research Group (MARG) at Manipal University, Karnataka, India; and a Research Fellow in the Earth System Governance Project. She is currently a Visiting PhD Scholar (2014-15) in the Leiden University Institute for Area Studies (LIAS), the Netherlands. Ramu C. M. is a Postgraduate Scholar in the Department of Geopolitics and International Relations at Manipal University, Karnataka, India. He works on geological security among other issues.
No comments:
Post a Comment