Briksdalsbreen in western Norway: AD 1900-2004 frontal fluctuations as a combined effect of variations in winter precipitation and summer temperature

Abstract

Mountain glaciers and ice caps are sensitive to changes in regional and global climate. Temporal glacier variations, manifested in change of volume, area and length, provide some of the clearest signals of climate change in nature. Therefore, glaciers are considered key indicators for the detection of global warming. Except for a few glaciers in western Scandinavia, glaciers in Europe are in retreat, following the global trend. Maritime (coastal) glaciers in western Norway experienced positive mass balance and large frontal advance during the 1990s because of increased winter accumulation. In contrast, after 1996, and especially since 2001, these glaciers have experienced strong negative mass balance and, as a result of short (< 5 years) response time, frontal retreat. Briksdalsbreen, a short and steep outlet glacier from Jostedalsbreen (the largest glacier on mainland Europe), retreated 230 m between 1996/97 and 2004, with a maximum annual retreat of 130 m in 2003/2004. This is the largest annual retreat recorded since the start of the frontal measurements in 1900. This study demonstrates that glacier fluctuations are not only a response to ablation-season temperature variations, but are also highly dependent on accumulation-season precipitation. The records of glacier-front variations and the climate variability over the last-100 years in western Norway may be regarded as a ‘modern analogue’ for other Holocene events and are useful in evaluating the likelihood that similar climate and glacier variability will occur in the future.