Research
Belspo-Bilateral agreements (1997-2000)
Glacier fluctuations and climatic change in South Siberia
Project description
Global mean temperatures have risen over the past 100 years by about 0.6°C. Over half of the increase has occurred in the last 25 years (IPCC). Glaciers all over the world react to these variations in background temperature, primarily by retreating. This is valid for most glaciers outside Antarctica or Greenland. They are therefore considered to be potentially good climatic indicators.
One way to determine the state of a glacier is by determining its mass balance. During winter, a glacier gains mass from accumulating snow. During the following summer some, and sometimes all, of that winter accumulation is lost due to melt. The difference between the accumulation and melt (or ablation) describes the annual net mass balance, which is equal to change in glacier volume.Mass balance measurements on more than 280 glaciers all over the world indicate that in most regions of the world, glaciers are shrinking in mass.
The majority of source information with respect to the dynamic response of temperate glaciers with changing climate comes from European and, to a lesser extent, North-American glaciers, while the share of the European glaciers in the world glacier area consists of only 3%. Hence, our knowledge on the glaciers of remote and hardly accessible mountain regions, often characterized by a high degree of glacierization, is rather limited. This biased distribution of glaciological source information severely constrains present attempts to assess the impact of climate change on the global glacier volume. It also hampers a full understanding of glacier dynamics and the impact of different climatic conditions. This project intends to expand the current global glaciological record by presenting and analyzing data gathered on Sofiyskiy Glacier, located in the Russian Altai Mountains, and collected during four consecutive summer field seasons in the period 1997-2000.
The climate of the Altai Mountains exhibits two important characteristics which contribute to the specific interest of this study area. First, the extreme continentality gives rise to aridity and large diurnal and seasonal temperature range. Second, owing to the coincidence of both accumulation and ablation season in summer, we can characterize the Altai glaciers as summer-accumulation type glaciers. Although current knowledge on the behaviour of these glaciers is limited, they are reported to be more vulnerable to the current global warming trend than the better known (maritime) winter-accumulation type glaciers. During this project, the basic characteristics of Sofiyskiy Glacier were investigated, such as surface mass balance and velocity, and the historical front variations. To gain a better understanding of the glacier's dynamics, we also performed a force-balance analysis and an analysis of basal conditions using a three-layer reflectivity model for electromagnetic pulses.
Complementary resources about this scientific project
Project team
Project Coordinator: Hugo Decleir and Frank
Pattyn
Vrije Universiteit Brussel (VUB)
Vakgroep Geografie
Pleinlaan 2
B-1050 Brussels
Tel: +32 (0)2 629 33 84
Fax: +32 (0)2 629 33 78
hdecleir@vub.ac.be
fpattyn@vub.ac.be
www.vub.ac.be/DGGF