Possible 1,000-kilometer-long river running deep below Greenland's ice sheet
Hokkaido University
Computational models suggest that melting water originating in the deep interior of Greenland could flow the entire length of a subglacial valley and exit at Petermann Fjord, along the northern coast of the island. Updating ice sheet models with this open valley could provide additional insight for future climate change predictions.
Radar surveys have previously mapped Greenland's bedrock buried beneath two to three thousand meters of ice. Mathematical models were used to fill in the gaps in survey data and infer bedrock depths. The surveys revealed the long valley, but suggested it was segmented, preventing water from flowing freely through it. However, the peaks breaking the valley into segments only show up in areas where the mathematical modelling was used to fill in missing data, so could not be real.
Christopher Chambers and Ralf Greve, scientists at Hokkaido University's Institute of Low Temperature Science, wanted to explore what might happen if the valley is open and melting increases at an area deep in Greenland's interior known for melting. Collaborating with researchers at the University of Oslo, they ran numerous simulations to compare water dynamics in northern Greenland with and without valley segmentation.
https://www.eurekalert.org/pub_releases/2020-11/hu-p1r111120.php
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A lot of unknowns, but interesting non-the-less.