Rapid disintegration of Alpine glaciers observed with satellite data

Abstract

[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 (À1.3% a À1 ) 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 3 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.

Quantifying changes and trends in glacier area and volume in the Austrian Ötztal Alps (1969-1997-2006)

“…Knoll and Kerschner, 2009;Paul et al, 2004). Elevation changes between 1997 and 2006 are plotted in Fig.…”

Climate Warming and the Recent Treeline Shift in the European Alps: The Role of Geomorphological Factors in High-Altitude Sites

“…After the 1980s, climatically driven dynamics due to a temperature increase have been particularly strong in the Alpine environment: accelerating glacier retreat (Paul et al 2004), changes in growth periods and phyto-phenological trends (Defila and Clot 2005), altitudinal shifts of vegetation belts and changes in vegetation composition at highaltitude sites (Theurillat and Guisan 2001;Walther et al 2005). According to Kullman and Ö berg (2009), treeline positions in the Swedish Scandes have reached their preLittle Ice Age position and the current treeline shift is an 'anomalous event in Holocene vegetation history', especially for its unique trend break.…”

“…In particular, a strong increase in the mean temperature of about ?1.7°C was recorded in Switzerland for the 30-year period 1975(Rebetez and Reinhard 2008, potentially inducing strong impacts on high-altitude ecosystems. Glacier retreat and disintegration (Paul et al 2004), permafrost degradation and correlated rockfalls (Haeberli and Gruber 2009) and changes in snow-cover duration (Hantel and Hirtl-Wielke 2007) are only a few examples of the marked effects of temperature changes on glacial and periglacial environments. On the other hand, the biological components have also been strongly involved and the ongoing climatic trends are inducing changes in the vegetation structure and biodiversity of high-altitude environments.…”

A comparison of glacier melt on debris-covered glaciers in the northern and southern Caucasus

“…4 % between 1969and 1997and 19.1 % in the period 1969(Lambrecht and Kuhn, 2007Abermann et al, 2009). In Switzerland, glaciers in the same size class lost 17.9 % between 1973 and 1999 (Paul et al, 2004). Therefore glaciers with a comparable size lost somewhat less area in the Caucasus compared to the glaciers in the Alps.…”

“…This is best achieved by the use of satellite imagery (Paul et al, 2004;Stokes et al, 2007) and an important aim of a number of studies was the determination of supra-glacial debris thickness using remote sensing information (Mihalcea et al, 2008b;Foster, 2010). Several studies attempted to include debris cover into glacier melt parameterisations with a different degree of sophistication (e.g.…”