Introduction to the triangular defect: The Karola Glacier is well-known for its appearance in the movies "Red River Valley", "Battle of Gyantse", and "Yunshui Yao". In 1996, in order to shoot the avalanche scene, the crew of the movie "Red River Valley" A large piece of the glacier was blown away, and the clearly visible triangular defect on the Karola Glacier today is the trace left behind at that time.