A giant underground river fed by melting ice could flow in a state of eternal darkness far below the surface of Greenland, according to a new study.
Nicknamed the “Dark River”, this hypothetical waterway – if it really exists, ie. – can stretch for 1000 kilometers (620 miles), running from the deep interior of Greenland to the Peterman Fjord in the northwestern part of the country.
“The results are in line with a long sub-glacial river,” said Christopher Chambers of the Hokkaido University in Japan, “but there is considerable uncertainty.”
This uncertainty stems in large part from significant gaps in radar data from aerial surveys over Greenland’s ice sheet, which over the years have revealed fragmented views of what looks like a giant, subglacial valley system that stretches over large parts of Greenland.
Numerous studies over the past few decades have suggested that such trenches, valleys or “megacanyons” may lie hidden in the subglacial environment, and also float the idea that liquid water can flow to the bottom of the characteristics.
Due to data gaps – given the scarcity of air travel mapping these deep contours – it is not known whether all the valleys are connected in a long, winding river or just segments of unrelated phenomena, let alone how water can stay down there.
“We don’t know how much water, if any, can flow through the valley and whether it really comes out at Peterman Fjord or is frozen or escapes from the valley along the way,” Chambers said.
In a new study designed as a “thought experiment,” Chambers and his team explored the hypothetical possibility that the valley would not be broken into pieces but flow continuously into a long river.
Such a possibility is plausible, they say, given that the segmentation seen in modeling before may be an illusion – phantom increases resulting from misleading modeling in scarce data rather than territorial characteristics.
“The increase occurs where data is interpolated to fill gaps between where the radar received reliable data,” the authors wrote in their new report. “This suggests that the rise of the valley may not be real.”
In the new modeling, the researchers suggested that the Dark River was indeed a continuous feature. Based on this scenario, the simulations assume that the waterway flows from the center of Greenland to the sea, with liquid water flowing in a continuous path.
“Along its length, the valley road gradually progresses down a slope of the ice surface, which leads to a decrease in the pressure of the ice sheet, which can allow water to flow in its path,” the team wrote.
While the findings remain hypothetical for now, researchers believe that future aerial surveys may one day be able to confirm the simulations.
If so, this will not only tell us that the Dark River is real, but will also mean that we have reached a new level of ability to model the behavior of the Greenland ice sheet – an extremely complex and mysterious body that is expected to has a huge impact on future sea level rise.
The findings were reported in The cryosphere.