Glacier recession in Iceland and Austria

Valley and mountain glaciers and ice caps respond to changes in regional climate on the scale of decades; thus, they can serve as indicators of regional climate change. During the last century, most valley and mountain glaciers and ice caps receded [Meier, 1984; Haeberli et al., 1989], although some advances have occurred during periods of cooling [Wood, 1988]. Glaciers in Iceland [Rist, 1975] and in the eastern Alps of Austria [Patzelt, 1980] have followed a similar pattern. Images acquired by satellite sensors can provide a regional overview for studying changes in glacier area, terminus position, glacier facies [Williams et al., 1991], and the position of the regional snow line, while insitu studies usually provide measurements at only a single point. Major changes in glaciers may be obvious from initial inspection of satellite images; however, detailed study of digital image data can reveal the presence of small changes that are useful indicators of regional trends in glacier mass balance. If observed over a long enough period of time in many different geographic settings, glacier-terminus position changes can be related to changes in regional and even global climate.