A new glacier monitoring site in West Greenland

Abstract:

Greenland’s mountain glaciers and ice caps have recently been shown to significantly contribute to current and future sea-level rise. Despite their importance in this respect they are heavily undersampled with only about 5 currently monitored glaciers out of more than 20000 distributed over complexly varying climatic regions. In 2012, Asiaq, Greenland Survey initiated therefore a glacier mass balance program at Qassinnguit glacier (64°9’N, 51°17’W), approx. 18 km East of Nuuk, Greenland’s capital. The glacier is a representative example for mountain glaciers in South-West Greenland both in terms of size (ca 1 km²) and orientation (N). A dense stake network gives the basis for the determination of the surface mass balance with the glaciological method as well as flow velocity measurements and the first two complete years are presented. An automated camera is used to monitor ablation patterns and the evolution of the snow line. In early 2014, a ground-penetrating radar campaign was performed to determine the glacier volume. Ice thicknesses up to 50 m were measured with a 100 MHz antenna and the glacier was found to be largely cold-based with some minor temperate parts. In addition to direct glaciological measurements at the site, the monitoring program complements a 7 year long time series of runoff, which allows for quantifying Qassinnguit glacier’s cryospheric contribution to the total catchment. In summer 2014 an on-glacier automated weather station was installed that measures parameters to determine the surface energy balance. Preliminary results will be presented and put into a larger spatial context by relating them to measurements with the same setup at an outlet glacier of the Greenland ice sheet approximately 100 km further East. Climate between these sites differs considerably with a marked negative West – East precipitation gradient.