Five decades of changes in the glaciers on the Friendship Peak in the Altai Mountains, China: Changes in area and ice surface elevation

Abstract

Mountain glaciers are indicators of climate change and of current water resources. They are important ecological systems and can be used to support sustainable development of industry and agriculture. However, due to climate warming, most glaciers are in a state of rapid retreat. Using topographic maps in 1959, ASTER remote sensing data in 2008 and ASTER digital elevation models (DEMs), area, ice surface elevation, and volume changes of glaciers on the Friendship Peak in the Chinese Altai Mountains were analyzed. Results showed that the collective area of all 201 glaciers investigated was reduced by 30.4% from 1959 to 2008. Fifty-five glaciers disappeared entirely. The average rates of reduction in area of glaciers with sizes <0.5, 0.5–1, 1–4, 4–10, and >10km2 were 25.9%, 30.8%, 30.9%, 35.9%, and 27.4%, respectively. From 1959 to 2008, the elevation of the glacier surface decreased by 20m at an average rate of 0.4ma−1. For the Kanas Glacier, the changes in ice surface elevation ranged from −101 to +38m. Results showed that glaciers at lower altitudes and smaller sizes experienced more extensive changes in elevation. The intensive glacier ablation over the Friendship Peak in the Altai Mountains was found to be caused by increases in the regional temperature, which occurred at an average rate of 0.52°C per decade.