The Greenland Ice River
The behavior of rapidly flowing ice (currents) in the polar territories is not well understood. They are like rivers that discharge icebergs into the ocean and account for half of the mass loss of the Greenland ice sheet. Many of these ice currents have doubled their velocities during the last decade, so it is necessary to understand the processes to be able to correctly include them in predictive models on the loss of ice mass, and therefore, the estimates of sea level rise for the future.
In northeastern Greenland lies the largest of these currents which begins precisely at the central ice summit and heads in the form of a wedge to the east coast to reach the ocean through three large ice streams (Nioghalvfjerds isstrømmen, Zachariae isbræ and Storstrømmen): the Northeast Greenland Ice Stream (NEGIS).
It is believed that at the beginning there is a strong fusion of ice at the base and it is estimated that ice reaches speeds in excess of 100 meters (109.3 yd)) per year in a distance of 200 km (124 mi) from the ice summit. Studies of the flow pattern of the inner layers could help determine if this ice flow has been permanent or if it can be “turned on and off” depending on the circumstances.
The drilling of an ice core through the 2,550 meters (8366 ft) of ice to the rocky bed is one of the goals of the EastGRIP base, that lays just above it. It is a question of studying the dynamics of the ice flow and the deformation of the ice through this core, which will cross layers more than 50,000 years old. The climatic studies of this period, especially the modern inter-glacial (the last 11,000 years) ones, are relevant because it is a period in which there are no records of high resolution chemistry and greenhouse gases. It is an important objective for the project, as they could obtain data of the last 25,000 years.
This deep drilling in the NEGIS should be supplemented by additional studies of the ice current, of which the WindSled will collect data and information, as well as the AWS Polarstern research vessel. A seismic project will also be performed, especially at the ‘ice river’ start area to understand why it is there.
The drilling project will be extended up to year 2020. The EGRIP project will provide a unique insight into the flow of ice currents leading to improved predictions of sea level rise.