CORDIS - EU research results

Where is the water under the Greenland ice sheet?

Final Report Summary - WATERUNDERTHEICE (Where is the water under the Greenland ice sheet?)

Water under the Greenland ice sheet influences the shape and flow of the ice and thus the ice sheet's reaction to globale warming. Ice with a wet bed flows faster, reacts rapidly to changes in climate and the basal-melt water contributes to the fresh-water supply to the ocean from the Greenland ice sheet. This is why ice streams into the fjords around Greenland can have ice velocities up to 10-15 km per year and the increasing velocities of these ice streams significantly contribute to the loss of mass from the Greenland ice sheet.
We have traced radio-echos sounding layers from airborne measurements in collaboration with Center for Remote Sensing (CReSIS) at University of Kansas in order to map the melt water extent of the Greenland ice sheet. The mapped layers have also been used to develop ice-sheet models combined with hydrostatic models for the movement of the basal water to predict the ice-sheet’s response to climate change. A web-based interface for browsing the CReSIS database of radio-echo-sounding images, in combination with a Greenland map. The software is available as open source at
At the deep drill site NEEM on the Greenland ice sheet a rock drill has been developed and 7-10 m of mixed ice, gravel and rocks have been drilled to investigate the interface between melting ice and the bedrock at the bottom of the 2540 m deep borehole. Samples have also been taken for dating the oldest ice here and for investigating DNA to map the flora and fauna that was here before the ice covered Greenland.
After the ice core was drilled the shape of the borehole has been followed by borehole logging. Combination of the ice core properties, the borehole results and the radio echo sounding data show that the 120.000 year old ice from the previous warm interglacial, the Eemian is hard to deform and folding and buckling structures under the ice consists of this hard deforming ice.
Results from the NEEM ice core show that it was 5 oC warmer during the Eemian period and the Greenland ice sheet was reduced at most with 25% of its volume. Together with the results from the dna and age studies of the basal ice we conclude that the Greenland ice sheet is more resilient to a warming climate than believed earlier. More than 10 oC warming is needed to melt the whole ice sheet and we believe that the present ice sheet is more than 400.000 years old.
Ice sheet models have been built and related to the radio echo dataset so improve our ability to predict changes of the volume of the Greenland ice sheet. The Greenland ice sheet will be a major contributor to the sea level rise we will experience in the next 100 years and the understanding of the ice streams discharging ice into the ocean must be improved. A study of the regional sea level predictions in Northern Europe shows that while the most likely sea level rise in Copenhagen is 0.65 m for the RCP8.5 scenario, there is a 5% risk for a 1.65 m sea level rise in 2100.

Documentation of the project can be seen on EURONEWS: