Science / project summary
In Greenland, fast-flowing ice streams discharge into the ocean, accounting for about half the loss of Greenland’s ice sheet mass. Many of these streams have doubled their rates of flow in the last decade. The biggest ice stream begins at the central ice divide and cuts through the ice sheet in a wedge shape to feed into the ocean through three large ice streams in northeast Greenland (Nioghalvfjerds isstrømmen, Zachariae isbræ and Storstrømmen). The North East Greenland Ice Stream (NEGIS) begins on the ice divide, which is believed to be caused by strong melting at the base, and reaches velocities of over 100 meters per year about 200 kilometers (km) from the ice divide, a region that is still 500 km from the coast where the ice is heavily crevassed and therefore dangerous. Researchers on the international East Greenland Ice Sheet Project (EGRIP) will establish a field camp in the area 200 km from the ice divide and drill an ice core down to bedrock, about 2550 meters in depth. Researchers have three primary research objectives: • Study the dynamics of the ice flow in an ice stream by ice rheology and deformation studies of the ice core. • Study the dynamics of the ice flow by borehole observations of basal sliding, borehole deformation, and basal water processes. • Obtain the highest quality brittle zone (650 m – 1250 m depth) ice core possible to allow for continuous analysis of climate parameters and greenhouse gases and ice core dating in the early Holocene. Information gleaned from the ice core, combined with information from borehole observations, will help scientists better understand the flow dynamics of NEGIS, and by extrapolation, of other ice streams. When results are reflected in ice sheet models, they will enable predictions of future loss of mass from the ice streams, thus improving estimates of future sea level rise.