Glaciers in the mountains of India, Nepal, and Tibet are melting . . .
Lakes sometimes form on top of the glaciers. When they grow too rapidly, they burst over natural rocky dams and surge down river valleys — with the potential to destroy villages below. Japanese scientists spotted this hazard in the Himalayas in the early 1990s. They teamed up with Nepalese engineers to build canals to control the flow of meltwater coming off glaciers. And they built alarm systems that ring in the villages when water levels at the top of the glaciers rise or fall.
Jeffrey Kargel: But now we have the ability to monitor these lakes from satellites, and it’s not a replacement for ground-monitoring and these alarm-systems, but it’s a complement to these systems.
That’s Jeffrey Kargel at the U.S. Geological Survey in Flagstaff, Arizona. He and his colleagues began studying Himalayan glaciers by satellite some years ago. With the help of scientists around the world, they monitor the temperature and growth of the glacial lakes. And they keep an eye out for any that might become a hazard to human populations in the area.
Kargel hopes that because this flooding frequently crosses national boundaries, the countries of the region will work together to study this potentially dangerous phenomenon.