Changes in surface elevation and extent of the Kaskawulsh Glacier, Yukon Territory

Abstract

Between 1977 and 2007, the Kaskawulsh Glacier underwent an overall decrease in volume of between 2.76 km3 water equivalent (we) and 4.60 km3 we, and a decrease in area of 2.27%. Volume losses are consistent with changes observed at most glaciers in the Yukon/Alaska region which are thinning and/or retreating (Arendt et al. 2006; Chen et al. 2006a; Larsen et al. 2007; Molnia 2007). The rate of volume change over the periods 1977-1995 and 1995-2007 remained constant at -0.52 km3 yr-1 we, while between 2000 and 2007 the glacier gained volume at a rate of 1.04 km3 yr-1 we. Gains in the recent 2000-2007 period result from prominent thickening in the accumulation area above 1989 m (+16.9 m) and minor thickening in the ablation area (+0.5 m). The observed thickening pattern is similar to patterns observed in Greenland (Chen et al. 2006b; Johannessen et al. 2005; Luthcke et al. 2008b), Antarctica (Davis et al. 2005), the Karakoram Himalaya (Hewitt 2005), New Zealand (Chinn 1999; Hooker and Fitzharris 1999), Scandinavia (Bamber et al. 2004; Chinn et al. 2005, Nesje et al. 2000), and Alaska (Arendt et al. 2008; Muskett et al. 2(03). Between 1956 and 2007, the glacier terminus retreated by an average of 655 m (13 m yr-1). No scaling ratio between terminus retreat and volume change could be established for the Kaskawulsh Glacier for the period 1977-2007.