An avalanche broke a glacier into Thorthormi Lake causing it to overflow and flood on October 30. Experts from NCHM said that the Thorthormi Automatic Water Level Sensor recorded a sudden decrease in water levels, indicating a breach of the lake. They said rising temperatures caused the glacier above the lake to melt, causing an avalanche. The glacier is no longer intact and the moraine dam between Thorthormi and its subsidiary lake is exposed, experts who examined the lake for three days said.