Latest NASA (National Aeronautics and Space Administration) satellite maps reveal that most of the world's glaciers are shrinking. Rick Wessels of the US Geographical Survey, based in Arizona, compared thousands of satellite images to aerial photographs dating back 20 years and found almost every mountain glacier in Patagonia, the Himalayas, the Alps and the Pyrenees, in Europe, had shrunk by several hundred metres. Wessels also studied images of mountain lakes at the base of melting glaciers that have grown over the last 10 years and found higher sediment levels. This suggests that there has been increased erosion of mountains by glaciers ( New Scientist, June 4, 2001).