Science Cracks in the Greenland ice sheet are growing faster and faster

SDA

3.2.2025 - 11:00

Cracks in the Greenland ice sheet are growing faster and faster. (archive picture)
Cracks in the Greenland ice sheet are growing faster and faster. (archive picture)
Keystone

New data shows: The Greenland ice sheet is cracking faster and faster. Climate change is increasing the formation of crevasses and could drastically accelerate the loss of ice.

Keystone-SDA

The crevasses in the Greenland ice sheet are growing ever faster. This is the conclusion of a study by an international research group reported in the journal "Nature Geoscience". According to the study, the cracks in the ice sheet have widened significantly in just five years. The scientists warn that this process could accelerate the loss of ice - with serious consequences for sea level rise.

The team led by Tom Chudley from Durham University in the UK analyzed more than 8,000 3D surface maps of the ice sheet, which were created from high-resolution satellite images. The data shows that the crevasses on the fast-flowing edges of the ice sheet have become larger and deeper between 2016 and 2021. According to the study, this development is happening faster than previously observed.

Tensions in the ice cause crevasses

Crevasses are wedge-shaped cracks that form when a glacier moves unevenly. The ice flows at different speeds: often faster at the surface and in the middle than at the edges or in deeper layers. This creates tensions that cause the ice to break up.

As the research group writes, these dynamics are shifting due to climate change. Higher temperatures allow the ice to flow faster, causing the cracks to widen and push deeper into the ice. The study shows that at the edges of the ice sheet, where large glaciers meet the sea, the glacier flow speed has increased. This has led to a significant increase in the volume of crevasses. In some sectors, this increase was up to 25 percent in 2021 compared to 2016, with a margin of error of around ten percent.

The increase was offset by a decrease in crevasses on Sermeq Kujalleq ("Southern Glacier"), the fastest flowing glacier in Greenland, whose movement had temporarily slowed down during the study period. However, the flow rate of Sermeq Kujalleq has since increased again, indicating that the period of equilibrium between the growth and closure of crevasses on the ice sheet is now over.

Crevasses as a sign of accelerated ice loss

"In a warming world, we would expect more crevasses to form. This is because glaciers are speeding up in response to warming oceans and the meltwater filling the crevasses is pushing the cracks deeper into the ice," lead author Chudley is quoted as saying in a statement.

The study now makes it possible for the first time to detect a significant increase in the size and depth of crevasses on fast-flowing glaciers at the edges of the Greenland ice sheet over periods of five years or less, Chudley added. "From this dataset, we can see that the crevasse fields are not just expanding into the ice sheet, as previously observed, but that the changes are primarily in the existing crevasse fields becoming larger and deeper."

Co-author Ian Howat, Director of the Byrd Polar & Climate Research Center at Ohio State University, adds: "As crevasses grow, they feed the mechanisms that cause the ice sheet's glaciers to move faster, driving water and heat into the interior of the ice sheet and accelerating the calving of icebergs into the ocean." These processes could in turn accelerate the ice flow and lead to the formation of more and deeper crevasses - "a domino effect that could accelerate ice loss in Greenland," says Howat.

Rising sea levels as a consequence

According to the study, Greenland has already contributed to a rise in sea level of around 14 millimetres since 1992. If the trend continues, the meltwater from the ice sheet could raise global sea levels by up to 30 centimetres by 2100. If all of Greenland's ice were to melt, sea levels could rise by as much as seven meters.