Lake on glacier creating cracks in Greenland’s ice: Study

Bremen, Germany (dpa) – A lake of meltwater has created deep cracks in Greenland‘s ice, according to a new scientific study.

As a result, the 79°N Glacier is showing initial signs of becoming more unstable, the research team from the Alfred Wegener Institute (AWI) in the northern German city of Bremerhaven reported in a study published on Thursday.

Lake forms in middle of the glacier

According to the scientists, Greenland‘s ice has been receding since the mid-1990s, with only three floating tongues remaining. One of these is the 79°N Glacier.

Increasing amounts of meltwater are accumulating on the surface of the 79°N Glacier. This has resulted in a lake that is now approximately 21 square kilometres in size.

Repeatedly, water from the lake abruptly broke through the ice and drained through cracks and shafts, the research team reported. This allowed massive amounts of water to reach the edge of the glacier tongue towards the ocean. The scientists observed seven such drainage events, four of which occurred in the past five years.

Glacier threatened with increased instability

Since 2019, particularly noticeable triangular fracture fields have been forming in the ice, according to the AWI, which remain visible for years. Some cracks form channels with openings several dozen metres wide, through which water reaches the base of the ice sheet.

Although the cracks and channels change within the ice, they persist for a long time.

Whether the glacier will ever return to its former state is unclear.

The research team found that water reached beneath the glacier through the cracks. There, the water accumulated into an underground lake. Radar images show that a blister has apparently formed on this lake under the ice, pushing the glacier upwards at this point.