Rapid disintegration of Alpine glaciers observed with satellite data

Analyses of multispectral satellite data indicate accelerated glacier decline around the globe since the 1980s. By using digitized glacier outlines inferred from the 1973 inventory and Landsat Thematic Mapper (TM) satellite data from 1985 to 1999, we obtained area changes of about 930 Alpine glaciers. The 18% area reduction as observed for the period 1985 to 1999 (−1.3% a�1) corresponds to a seven times higher loss rate compared to the 1850–1973 decadal mean. Extrapolation of area change rates and cumulative mass balances to all Alpine glaciers yields a corresponding volume loss of about 25 km3 since 1973. Highly individual and non-uniform changes in glacier geometry (disintegration) indicate a massive down-wasting rather than a dynamic response to a changed climate. Our results imply stronger ongoing glacier retreat than assumed so far and a probable further enhancement of glacier disintegration by positive feedbacks. DOI: https://doi.org/10.1029/2004GL020816 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-62854 Published Version Originally published at: Paul, F; Kääb, A; Maisch, M; Kellenberger, T; Haeberli, W (2004). Rapid disintegration of Alpine glaciers observed with satellite data. Geophysical Research Letters, 31(21):L21402. DOI: https://doi.org/10.1029/2004GL020816 Rapid disintegration of Alpine glaciers observed with satellite data Frank Paul, Andreas Kääb, Max Maisch, Tobias Kellenberger, and Wilfried Haeberli Department of Geography, University of Zurich-Irchel, Zurich, Switzerland Received 23 June 2004; revised 20 September 2004; accepted 6 October 2004; published 12 November 2004. [1] Analyses of multispectral satellite data indicate accelerated glacier decline around the globe since the 1980s. By using digitized glacier outlines inferred from the 1973 inventory and Landsat Thematic Mapper (TM) satellite data from 1985 to 1999, we obtained area changes of about 930 Alpine glaciers. The 18% area reduction as observed for the period 1985 to 1999 ( 1.3% a ) corresponds to a seven times higher loss rate compared to the 1850–1973 decadal mean. Extrapolation of area change rates and cumulative mass balances to all Alpine glaciers yields a corresponding volume loss of about 25 km since 1973. Highly individual and non-uniform changes in glacier geometry (disintegration) indicate a massive down-wasting rather than a dynamic response to a changed climate. Our results imply stronger ongoing glacier retreat than assumed so far and a probable further enhancement of glacier disintegration by positive feedbacks.