Many mountain populations – such as the Andes or the Himalayas – rely on water from glaciers. However, changes in glacial water reserves, as well as projections of sea level rise, are largely dependent on glacier volume and thickness, both of which have so far been poorly assessed.
After analyzing more than 800,000 pairs of satellite images, researchers from the CNRS, Université Grenoble Alpes (France) and Dartmouth College (USA) created the first global flow rate map for 98% (> 200,000) of the world’s glaciers. Since glacial flow is a function of glacial mass, knowledge of the former allows us to estimate ice thickness and spatial distribution, which in turn determine the total amount of water in glaciers and their future contribution to sea level rise.
The researchers’ findings suggest that glacial water reserves in the Himalayan Indus and Chennai watersheds are a third larger than previous studies estimated before new satellite data became available. In contrast, the volume of water in the tropical glaciers of the Andes, which can withstand more than 4 million people, could be up to 23% less than previously thought.
The present study is published in NASA) satellite imagery that was analyzed on Université Grenoble Alpes servers (>106 h of computer processing time). It had support from the French space agency (CNES).
For more on this research, see New Atlas of Globe’s Glaciers Finds They Have Less Ice Than Previously Thought.
Reference: “Ice velocity and thickness of the world’s glaciers” by Romain Millan, Jérémie Mouginot, Antoine Rabatel and Mathieu Morlighem, 7 February 2022, Nature Geoscience.
https://scitechdaily.com/new-calculations-of-worldwide-glacial-flows-and-volumes-from-over-800000-pairs-of-satellite-images/ New estimates of global glacial flows and volumes with more than 800,000 pairs of satellite images