Earthquake or ice avalanche? Here’s what caused the Nepal-Tibet flash floods

What caused the Nepal floods?

Initial comments from Nepal’s foreign minister suggested that an earthquake was reported in the mountainous area moments before a landslide, signalling it may have caused the flash floods. The US Geological Survey (USGS), however, counters those claims despite originally reporting a magnitude 4.4 quake.

Offering an update on the situation on August 26 at 6:44 pm UTC, the USGS stated a magnitude 5.2 seismic event took place near the border between Nepal and China at 8:37 am local time Wednesday. It further determined that the seismic event was actually generated by a glacial collapse and debris flow, not an earthquake, causing subsequent horrifying impacts downstream.

Similarly, Nepal’s disaster management pointed towards an initial study of Planet Labs satellite imagery, indicating that an ice and rock avalanche triggered a flood in the Lhende Khola River, about 20 km northeast of the Nepal-China Rasuwagadhi border crossing.

Reuters further reported that the resulting mudslide eventually hit Gyirong port in Tibet and Nepal, triggering high-speed flash floods that wiped out roads, power projects and villages in their path.

How many people are dead and missing?

Although the current death toll estimation stands at least at 165, Nepali authorities are expecting these numbers to rise sharply. Among the nearly 1,500 people unaccounted for on both sides of the border, approximately 750 are foreigners, including many who were on a pilgrimage to the Kailash Mansarovar site.

In Nepal, these numbers include 177 Indians, 63 Americans, 53 Ukrainians, 34 Australians, 33 British citizens, 28 Malaysians and 25 Canadians, according to Reuters. 9 South Korean nationals, who work at a hydropower plant, are also missing, in addition to nationals of about 20 other countries reported unaccounted for.

Nepal’s Foreign Minister Shisir Khanal has since stated at an NDTV summit in Kathmandu that at least 300 Indian nationals, mostly Mansarovar pilgrims, have been reported missing.

In India’s Bihar (downstream from Nepal), about 5,000 people were evacuated in the aftermath of the tragic deluge. More than 5,000 army and police personnel were deployed as part of rescue efforts.

The Andhra Pradesh government said 28 pilgrims from Tirupati, who were stranded amid Nepal floods, have been found safe and are currently in Kathmandu. Efforts to trace other residents, who are still unaccounted for, are ongoing.  State Emergency Operation Center (SEOC), Maharashtra, however, revealed that more than 80 citizens of Maharashtra were reported stranded in Nepal.

Several countries have promised humanitarian aid, with India sending a second consignment of 37.5 tonnes of relief material carrying medicines, food and other supplies, on Thursday. The initial 10-tonne delivery of relief supplies, executed the previous day, consisted of blankets, solar lamps, temporary shelters, hygiene kits and medicines.

National Disaster Response Force (NDRF) Inspector General Narendra Singh Bundela emphasised that there has been no “adverse” flood impact reported in Indian border territories so far.

“The State Government is already monitoring this. As of now, there has been no adverse impact. The CWC (Central Water Commission) is also monitoring the water level discharge. After reviewing the situation, the State Government has made additional deployments and diverted state resources. The District Magistrate has already taken action at the field level and completed sensitisation. So, this is currently being monitored to see what further possibility of flooding there might be,” Bundela told ANI.

“The border districts–such as Kushinagar and West Champaran–which could be affected initially, are also already being monitored. For that, we have reserve teams on standby. If anything like this happens, in coordination with the State Government, they will be deployed immediately.”