Although the sudden floods that occurred in Nepal yesterday (26), killing hundreds and leaving thousands missing, were initially believed to have been caused by an earthquake, the latest reports say that the actual cause was a glacier collapse.
The United States Geological Survey’s automatic earthquake detection network initially reported the event as a magnitude 5.2 earthquake. However, the agency later clarified that it was not an earthquake, but the result of a massive glacier collapse and a debris flow. The agency explained that the vibration caused when the glacier fell from a height of about 7,000 feet into the valley below was similar to that of a magnitude 5.2 earthquake.
The collapse of the glacier blocked the Lende Khola, a tributary of the Bhote Koshi River. At the same time, the ice from the glacier began to melt rapidly. These factors are now believed to have caused the flooding along the Bhote Koshi River in the Rasuwa area.
By comparing satellite images taken before and after the disaster, scientists have confirmed that a huge glacier broke away from a mountain near the Nepal-Tibet border and fell from a high elevation. An analysis by CNN shows that the ice mass, which had separated from the main mountain, fell into the river flowing through the valley below. This involved a drop of approximately 7,000 feet.
Because of global warming, Nepal is now becoming a country increasingly affected by climate-related disasters. Large masses of ice that have helped keep the Himalayan mountain range stable are melting, while rocky mountain slopes are becoming less stable and more fluid. Because of this, the ice from the collapsed glacier began melting rapidly, which is believed to have contributed to the speed and severity of the flooding. Daniel Shugar, a geologist at the University of Calgary in Canada who is studying the glacier collapse, said that the tremendous force of the collapse may also have caused the ice to melt faster.
The exact reason why this glacier collapsed has not yet been confirmed. Several teams of scientists are still investigating the incident. However, there is already growing scientific opinion that the long-term melting of glaciers in the Himalayas is directly connected to both the collapse of the glacier and the rapid melting of the ice after the collapse. Therefore, it is reasonable to say that we cannot consider this tragedy separately from the effects of global warming.
The melting of glaciers in the Himalayas and the polar regions is already a major environmental concern for scientists around the world. It is widely discussed as one of the reasons for rising sea levels. We know that small islands such as Tahiti, Tuvalu and the Cook Islands are at increasing risk of being submerged by the sea because of rising sea levels.
However, this incident reminds us that glacier melting and glacier collapses can cause river water levels to rise before their effects are seen in rising sea levels.
It is therefore becoming increasingly clear that global warming is a tragedy from which no part of humanity can escape—from people living close to sea level to those living high in the mountains of the Himalayas.