Landsat satellite data are increasingly used to track natural and anthropogenic changes to the land surface features of the planet. Changes to Bear Glacier in south central Alaska are illustrated by comparing 1980, 1989, and 2011 Landsat coverage.
Warming in the region has caused less buildup of snow, providing less material for glacial growth. As the glacier receded, ice at the end of the glacier broke off the main body, forming blocks of ice in the open water. The 2011 image shows considerable retreat of the tongue of the glacier.
The Landsat data are useful for study as the archive allows change over time sequences, the synoptic view allows a broad perspective of regions, and the observations can be acquired over areas where access is challenging.