Late‐twentieth century changes in glacier extent in the Ak‐shirak Range, Central Asia, determined from historical data and ASTER imagery

Abstract

Global analysis of glacier regimes reveals widespread wastage since the late 1970s, with a marked acceleration in the late 1980s. We investigate changes in the heavily glacierized Ak‐shirak Range, central Tien Shan plateau (43°N, 75°E) using air photo mapping surveys (1943 and 1977), an ASTER imagery (2001), and long term glaciological and meteorological observations. The wasting of the Ak‐shirak glacier system features a decrease in average glacier size, and an increase in the area of outcrops. A small shrinkage during 1943–1977 was followed by a greater than 20% reduction during 1977–2001 in response to increases in summer and annual air temperature and decreases in annual precipitation.