October 4, 2024

New Calculations of Worldwide Glacial Flows and Volumes From Over 800,000 Pairs of Satellite Images

Today research study, published in Nature Geoscience on February 7th, 2022, is based on Sentinel (ESA) and Landsat (NASA) satellite imagery that was analyzed on Université Grenoble Alpes servers (>> 106 h of computer system processing time). It had support from the French space company (CNES).
For more on this research, see New Atlas of Globes Glaciers Finds They Have Less Ice Than Previously Thought.
Referral: “Ice speed and thickness of the worlds glaciers” by Romain Millan, Jérémie Mouginot, Antoine Rabatel and Mathieu Morlighem, 7 February 2022, Nature Geoscience.DOI: 10.1038/ s41561-021-00885-z.

Ice flow speeds for Andean glaciers. Credit: © Romain Millan, Jean-Baptiste Barré/ CNRS/ IGE– Map data: Mapbox/ OpenStreetMap/ Maxar
Numerous mountain populations– in the Andes or Himalayas, for instance– depend on glaciers for their water. Yet modifications in glacial water reserves, like forecasts of water level increase, greatly depend on glacier volume and thickness, both of which have been badly examined– previously.
By analyzing over 800,000 sets of satellite images, scientists from the CNRS, Université Grenoble Alpes (France), and Dartmouth College (USA) have developed the first global map of flow speeds for 98% (>> 200,000) of the worlds glaciers. As glacial circulation is a function of glacial mass, knowing the previous enables one to approximate ice density and spatial distribution, which in turn identify the overall volume of water that glaciers hold and their future contribution to water level rise.
Ice flow speeds for Alaskan glaciers. Credit: © Romain Millan, Jean-Baptiste Barré/ CNRS/ IGE– Map information: Mapbox/ OpenStreetMap/ Maxar
The researchers findings recommend glacial water reserves in the Himalayan watersheds of the Indus and Chenab are a 3rd greater than approximated by previous studies, before the new satellite data were readily available. In contrast, the volume of water kept in tropical Andean glaciers, which sustains over 4 million people, might be up to 23% smaller than as soon as thought.