Scientists are investigating multiple possible causes behind Nepal’s devastating flash flood on 26 August, with the strongest early theory pointing toward a glacier or glacial-lake-related collapse combined with a massive landslide. According to the report, a huge section of ice at around 17,000 feet may have broken away and fallen thousands of feet into the valley, generating an extremely powerful flow carrying water, ice, rocks and debris through the Lhendu Khola system toward Nepal. Researchers cited in the report say seismic sensors detected a major rockfall signal around 8:40 a.m., but the initial signal did not appear typical of an earthquake. A 4.4-magnitude earthquake was also recorded near the Tibet-Nepal border, initially raising the possibility that seismic activity triggered the collapse. However, USGS reportedly later indicated that the seismic signal may have been caused by the landslide itself. Satellite imagery reportedly showed rapid loss of ice before the event. While warming can make Himalayan glaciers and slopes more unstable, scientists have not established a direct link to climate change in this particular disaster.
