According to a press release issued by the University of Bristol in the U.K., the team made the discovery by analyzing data collected, in part, with ice-penetrating radar. What they found was a drainage network extending throughout a basin estimated to cover more than 173,000 square miles, accounting “for about 20% of the total land area of Greenland.”
The size has been compared to that of the Ohio River Basin. While most of the surrounding terrain appears to be fairly even, the basin’s mountainous eastern side features gashes that are up to 7 miles wide and 4,500 feet deep.
Interestingly, the team believes the system was created by ancient rivers even before Greenland’s ice sheet developed about 3.5 million years ago. The hope is that this research adds to the scientific community’s understanding of preglacial landscapes and how they evolve over time.