Changes in glacier area in Tyrol, Austria, between 1969 and 1992 derived from Landsat 5 Thematic Mapper and Austrian Glacier Inventory data

Results are presented from the use of Landsat Thematic Mapper (TM) imagery and data from the Austrian Glacier Inventory for area change detection of a large number of glaciers. A trend analysis of glacier area between 1969, 1985 and 1992 was carried out for 235 glaciers in Tyrol, Austria. Ratio images from TM channels 4 and 5 are thresholded to obtain a glacier mask as revealed by analysis of the data for six sub-regions (Ötztal, Pitztal, Gurgl, Stubai North, Stubai South and Zillertal). Glaciers with areas less than 1 km 2 shrank significantly between 1969 and 1992 (about -35%). The total loss in area in this period is about 43 km 2 or -18.6% of the area in 1969 (230.5 km 2 ). Glaciers smaller than 1 km 2 contribute 59% (25 km 2 ) to the total loss although they covered only one-third of the area in 1969.