A newly released ASTER image from January 29, 2017 shows the rapid retreat of New Zealand’s glaciers. When the image is compared to a Landsat image from January 12, 1990, differences can be detected between the larger terminal lakes and the ice free of moraine cover for the Mueller, Hooker and Tasman Glaciers. In total, New Zealand contains over 3,000 glaciers, many located on the South Island in the Southern Alps, according to NASA. These glaciers have been in retreat since 1890, with only short periods of recorded advance during that time.
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), built by Japan’s Ministry of Economy, Trade and Industry, is one tool launched in 1999, along with four other Earth-observing instruments, used to monitor the changing surface of the planet. It allows scientists to better understand dynamic conditions, such as glacial advance or retreat, that are otherwise difficult to physically measure, and offers data critical for surface mapping.
See NASA’s images over the years of New Zealand’s glacier retreat.