Researchers have discovered that the Greenland Ice Sheet is cracking open more rapidly as it responds to climate change.The warning comes in a new large-scale study of crevasses on the Greenland Ice Sheet – the world’s second largest body of ice.Using 3-D surface maps, scientists led by Durham University found crevasses had significantly increased in size and depth at the fast-flowing edges of the ice sheet over the five years between 2016 and 2021.They hope their findings will allow scientists to build the effects of ice damage and crevassing into predictions of the future behaviour of the Greenland Ice Sheet.Climate change is rapidly accelerating in GreenlandIn Greenland, the increases in crevasses are happening more quickly than previously detected. Crevasses are wedge-shaped fractures or cracks that open in glaciers where ice begins to flow faster.The researchers say that crevasses are also getting bigger and deeper where ice is flowing more quickly due to climate change and that this could further speed up the mechanisms behind the loss of ice from the Greenland Ice Sheet.Greenland has been behind approximately 14mm in the rise in sea level since 1992. This is due to increased melting from the ice surface in response to warmer air temperatures and increased flow of ice into the ocean in response to warmer ocean temperatures, which are both being driven by climate change.Greenland contains enough ice to add seven metres of sea level rise to the world’s oceans if the entire ice sheet were to melt. Research has shown that Greenland could contribute up to 30cm to sea level rise by 2100.3D surface maps of the Greenland Ice Sheet reveal startling informationFor this latest study, the researchers used more than 8,000 3-D surface maps created from high-resolution satellite imagery to identify cracks in the surface of the Greenland Ice Sheet and show how crevasses had evolved across Greenland between 2016 and 2021.It revealed that at the edges of the ice sheet, where large glaciers meet the sea, accelerations in glacier flow speed were associated with significant increases in the volume of crevasses. This was up to 25% in some sections.These increases were offset by a reduction in crevasses at Sermeq Kujalleq, the fastest-flowing glacier in Greenland, which underwent a temporary slowdown in movement during the study period.This balanced the total change in crevasses across the entire ice sheet during the study period to 4.3%.However, Sermeq Kujalleq’s flow speed has since begun increasing again – suggesting that the period of balance between crevasse growth and closure on the ice sheet is now over.The future of ice sheet lossDr Tom Chudley, a Leverhulme Early Career Fellow in the Department of Geography at Durham University, said: “In a warming world, we would expect to see more crevasses forming. This is because glaciers are accelerating in response to warmer ocean temperatures and because meltwater filling crevasses can force fractures
Mar. Feb 4th, 2025
