A hypothetic model made by Scientists from Hokkaido University, University of Oslo, Utrecht University, and Norwegian Polar Institute indicates that a river is flowing by the melting of ice below the ice sheets of Greenland. The river is estimated to stretch 620 miles (1000km). Researcher Christopher Chambers and Ralf Greve wanted to analyze the conditions, if the valley opens up and the melting starts in the interior of the melting area of Greenland. Many tests were performed with the joint effort of the researchers at the University of Oslo to compare water dynamics in northern Greenland with and without valley segmentation.
The research has been published in The Cryosphere. With the updating of the ice sheets in the open valley where the river runs along can help us to estimate the future climatic changes. The river is estimated to be flowing in an entire length of a subglacial valley and runs from the melting site to the Petermann Fjord in northern Greenland.
Although the river exists there, it is still not estimated accurately due to the compelling cracks in the data of Greenland’s ice covers. Christopher Chambers said “The results are consistent with a long subglacial river, but considerable uncertainty remains. For example, we don’t know how much water, if any, is available to flow along the valley, and if it does indeed exist at Petermann Fjord or is refrozen, or escapes the valley, along the way.”
Previously it was estimated that there might be valleys or canyons under the ice sheet of Greenland and it was not known whether these structures are connected or not.
In the latest study, it has been analyzed that the melting water flows below the ice surface but a question still remains unanswered – Whether there is a riverbed under all of the ice or not? Christopher Chambers and the team performed tests over the hypothesis that the valleys are not broken up but they flow as a big river by simulating with the SICOPOLIS (Simulation Code for Polythermal Ice Sheets) method.
It proposed that there was enormous water flow towards the fjord with a level valley base set at 500 meters below sea level than the one set at below 100 meters. The simulated discharge increases down the entire valley only when the valley is unblocked. This happens when melting increases over the deep interior at a region of basal melting. The analysis suggests that the valley and the ice can permit to establish a down-valley water route.
Ralf Greve, working on the model used in the study, known as SICOPOLIS said “Additional radar surveys are needed to confirm the simulations are accurate. This could introduce a fundamentally different hydrological system for the Greenland ice sheet. The correct simulation of such a long subglacial hydrological system could be important for accurate future ice sheet simulations under a changing climate.”
Although the analysis performed is not accurate now, the team believes that when they get new data they will be able to give accurate information about it.
Source – hokkaido university