Investigating basal conditions and flow dynamics on Vestfonna Ice Cap, Svalbard

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The body of scientific evidence for significant anthropogenic impacts on the global climate is growing and public concern underscores a need for better assessments of contemporary environmental changes in regions such as the Arctic. Although the vast majority of ice on Earth is stored in Greenland and Antarctica, it is important to keep in mind that 70% of the cryospheric contribution to 20th century sea-level rise was attributed to the retreat of mountain glaciers and ice caps. Arctic ice masses are an important component of global change, especially as Arctic temperatures are increasing at almost twice the global average. This project focuses on Vestfonna Ice Cap in northeast Svalbard. This Arctic ice cap is of particular interest because its northern ice margin terminates on land while the southern margin contains a series of tidewater outlet glaciers, comparable to those draining the Greenland Ice Sheet. Airborne radio-echo sounding data collected in 1983 and 1986 by Scott Polar Research Institute showed that the volume of Vestfonna Ice Cap was about 500 km3. Aerial photographs and satellite imagery subsequently showed that flow speeds on the southern tidewater glaciers were several hundred metres per year. This was an order of magnitude faster than the surrounding ice and more than double the calculated balance velocities. It was suggested that this negative state of mass balance was a result of short-lived glacier surges. However, the interior ice plateau on Vestfonna Ice Cap is today experiencing widespread progressive thinning, either as a result of changing regional climate dynamics or enhanced discharge from outlet glaciers. This project proposes glaciological investigations on Vestfonna Ice Cap with the aim to quantify the link between climate dynamics and ice flow. The proposed investigations include the collection of radio-echo sounding data in a traverse across the ice cap and in two designated study areas, one on the northern ice margin and one on a southern tidewater glacier. The radar data provide a means to measure ice thickness and examine the nature of the bed, e.g. the distribution of melting and freezing and the presence of water, which serves as a lubricant. We will install two digital cameras near the terminus of Frazerbreen, which is a tidewater glacier, so that we can monitor the position of its calving ice front. A total of six GPS receivers will be installed on the ice to monitor horizontal and vertical motion on a sub-hourly timescale during an 18-month period. By combining GPS data with digital time-lapsed imagery, and output from an automatic weather station, we will be able to understand how forces are balanced in the ice cap and this will enable us to examine how the ice mass behaves under different climatic and oceanographic conditions. With the application of a 3D numerical ice-flow model, we will be able to study the response of the ice cap to global warming and predict its contribution to sea level change.