The National Centre for Hydrology and Meteorology says that an avalanche broke a glacier into the Thorthormi Lake, causing the lake to overflow about a week ago. Last week, the Thorthormi Automatic Water Level Sensor recorded a sudden decrease in water levels, indicating a breach of the Thorthormi Lake. The centre says the glacier above the Lake is no longer intact and the moraine dam between Thorthormi and its subsidiary lake is exposed.
Experts and officials from the centre spent around three days assessing the breach of the Thorthormi Lake. According to the experts, rising temperatures caused the glacier above the lake to melt, causing an avalanche.
The collapsed glacier entered the lake, initiating a wave of over 4 metres. This made some two billion litres of water to overflow. The officials found that the lake’s water level was reduced by more than 40 centimetres.
“The temperature had increased in the last three months. Due to the rise in temperature, the glacier melted. The glacier became unstable and we think the melting of the glaciers caused the flood,” said Karma Toeb, a Specialist with the National Centre for Hydrology and Meteorology.
Now that the glacier above the lake has collapsed, the experts fear that if there is another avalanche, the lake could experience excessive overflow, potentially causing a Glacier Lake Outburst Flood or GLOF.
According to the centre, the Automatic Water Level Sensor was damaged, making it difficult for the officials to measure the water level for now. They say they are closely monitoring the situation at Thorthormi Lake.
Karma Toeb said, “our staff stationed at Lunana used to go to assess the lake once a week. Now, we have asked them to assess it three times a week and report to us until the Thorthormi Lake becomes stable.”
The Automatic Water Level Sensor is expected to be repaired by today.
According to the NCHM, Thorthormi Lake has been a subject of concern due to its close proximity to the Raphstreng Lake which could cause a major GLOF.
Deki Lhazom
Edited by Sangay Chezom
