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A giant underground river fed by melting ice could flow in a state of perpetual darkness well below Greenland’s surface, new research has found.
Nicknamed the “ Dark River, ” this hypothetical waterway – if it really exists – can stretch for 1,000 kilometers (620 miles), flowing from the deep interior of Greenland to the Petermann Fjord in the northwest of the country.
“The results are consistent with a long subglacial river,” says ice cap modeler Christopher Chambers of the University of Hokkaido in Japan, “but considerable uncertainty remains.”
The suggested valley and the possible river. (Chambers et al., The cryosphere, 2020)
Much of this uncertainty stems from significant gaps in radar data from aerial surveys over the Greenland ice sheet, which over the years have detected fragmented glimpses of what looks like a system of giant subglacial valleys s ‘extending under large parts of Greenland.
Numerous studies over the past two decades have suggested that such trenches, valleys or “mega-canyons” may lie hidden in the subglacial environment, and have also suggested that liquid water may s ‘flow at the bottom of the characteristics.
However, due to data gaps – given the scarcity of air flights mapping these deep contours – it is not known whether all the valleys are connected in a long winding river, or just disconnected segments of phenomena, let alone. how the water could behave. The.
“We don’t know how much water, if any, is available to flow down the valley, and whether it actually comes out to Petermann Fjord or is refrozen, or escapes from the valley, along the way.” , says Chambers.
In a new study, designed as a “ thought experiment, ” Chambers and his team explored the hypothetical possibility that the valley was not divided into separate pieces, but flowed continuously in a long river.
Such a possibility is plausible, they say, given that the segmentation previously seen in the modeling could be an illusion – phantom elevations resulting from misleading modeling in data-poor regions, rather than territorial features.
“The increases occur where the data is interpolated to fill in the gaps between the places where the radar obtained reliable data,” the authors write in their new article. “This suggests that the valley climb may not be real.”
In the new modeling, the researchers assumed that the Dark River was indeed a continuous feature. Based on this scenario, the simulations suggested that the waterway flows from central Greenland to the sea, with liquid water flowing through the unbroken path.
“Along its length, the valley road progressively progresses on an ice surface slope, causing a drop in the pressure of the ice overburden which could allow water to drain along its path. », Writes the team.
While the results remain speculative for now, the researchers believe future aerial surveys may one day be able to confirm the simulations.
If so, it wouldn’t only tell us that the Dark River is real, but it would 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 have a considerable impact on future sea level rise.
The results are reported in The cryosphere.
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