Researchers from the University of Exeter have found Eiffel tower-sized ice channels beneath an Antarctic ice shelf. The channels expand for hundreds of kilometers along the ice shelf and are likely to have implications for the stability of the ice shelf. Their finding will give researchers new clues as to how the ice will behave under altering environment conditions.

Researchers from the University of Exeter and their colleagues at neighboring universities utilized satellite photos and radar data to locate the channels under the ice shelf. The channels are also visible on the surface of the ice shelf, as well as underneath. This is because the ice floats at a varying height based on its thickness.

The researchers surmised the course of meltwater flowing under the part of the ice touching the land — called the ice sheet. They found that the surmised flow courses matched up with the channels under the ice shelf at the point where the ice begins to float.

The match-up shows that the water movement beneath the grounded ice sheet is to blame for the development of the channels beneath the ice shelf. When the meltwater moving under the ice sheets encounters the ocean beneath the ice shelf, it results in the development of a plume of ocean water, which consequently melts out the large channels under the ice shelf.

Until now, it was believed that water moved in a thin layer beneath the ice sheet, but the findings from this work imply that it moves in a more concentrated manner. The fashion in which water moves beneath the ice sheet greatly impacts the quickness of the ice flow, however, the significance for the future of the ice sheet are yet to be established.

“If we are to understand the behaviour of the ice sheet, and its contribution to changes in sea level, we need to fully understand the role of water at the base of the ice sheet. The information gained from these newly discovered channels will enable us to understand more fully how the water system works and, hence, how the ice sheet will behave in the future,” professed Dr. Anne Le Brocq from the University of Exeter.

Ice channels of this size have been documented before elsewhere, but their development has been associated with oceanic processes rather than meltwater leaving the grounded ice sheet. With the link to the meltwater system realized, easily available data from the channels could offer new information on how meltwater moves at the base of a kilometer-thick ice sheet.