Nepal’s devastating earthquake Saturday 25th April 2015

April 30, 2015

The graphic pictures of the destruction of the older parts of Kathmandu and surrounding districts and of collapsed houses in remote villages are a stark reminder of the impact of earthquakes.

This latest major earthquake, measuring 7.9 on the Richter scale, has long been anticipated. The region is well known for its high seismic activity that is associated with the movement of the Indian tectonic plate northwards at a rate of 3-5 cm per year beneath the Himalayas and Tibetan Plateau. The magnitude of the expected earthquake in Kathmandu Valley was thought to be 8.0-8.4 and with casualties in the tens of thousands. That the number killed is currently around 5,500, while in itself is a dreadful tally, it is significantly less than expected given the size and location of the event. This may be a consequence of an extensive programme of earthquake preparedness from the Nepal Society of Earthquake Technology (NSET), based in Kathmandu, especially for schools and hospitals. The majority of buildings damaged or destroyed in Kathmandu Valley have tended to be historic structures, especially at Bhaktapur, a World Heritage Site some 30 km southeast of central Kathmandu (which was also badly damaged in the great earthquake of 1934), and Durbar Square, in the city centre.

I have been visiting Nepal regularly since September 1994 and was due to return to Kathmandu on the 9th May as part of an ongoing series of projects on glacial hazard assessments and earthquake preparedness training. In May 2008, I was involved with developing the Earthquake Emergency Response Plan for the British Embassy in Kathmandu with colleagues from the Foreign and Commonwealth Office. I also developed and presented a series of training courses on earthquake preparedness for embassy staff (expat and local). It has been gratifying to see the British Embassy providing shelter and physical support to British Nationals using the earthquake provisions and equipment. It more than justifies the efforts to establish such a resource, despite much opposition at the time to spending money on such facilities.

The trip I was about to undertake was to have involved flying by helicopter to a remote village called Beding, in the Rolwaling Valley, about 110 km northeast of Kathmandu. From there I was to have walked up the valley to the next village of Na before walking on further to undertake field work at Tsho Rolpa, Nepal’s largest and most hazardous glacial lake. I have undertaken many field expeditions to this region. Earlier this week, I was told that “a chunk of mountain” had collapsed between Beding and Na following last Saturday’s major earthquake and that it was not known if it is possible to go on foot up-valley from Beding. There have been many, many landslides and there are concerns for the people in these remote communities. We are now working with our client to obtain high-resolution satellite imagery following the earthquake to be able to assess what has happened in these remote regions and to be able to advise both hydropower developers with major projects on the Tama Koshi River as well as the authorities, on the damage that has occurred and the likely consequences to infrastructure and communities.

On a wider scale, having undertaken a regional assessment of glacial hazards across central and eastern Nepal in 2008, and having seen the latest graphic scenes of events across the Everest region, it is likely that these assessments will have to be redone in the light of satellite imagery yet to be acquired but following Saturday’s earthquake. It is necessary to do as much of this prior to the onset of the next monsoon, when the glacial lakes fill up. Should any of the moraine dams have been weakened by the earthquake, it is during the monsoon that Glacial Lake Outburst Floods (GLOFs) tend to occur. If the up-coming monsoon is severe, the already hard-pressed communities may have yet more to suffer over the coming months.

We are liaising with a number of organisations to see if we can access the necessary remote sensing imagery so that we can assist colleagues in Nepal with further hazard assessments. Funding remains an issue. If any readers have any suggestions or can assist, please contact us.