By Stephen BeechCracks in Greenland’s ice sheet are growing more rapidly due to climate change, reveals new research.The warning comes following major new high-tech analysis of crevasses on the world’s second-largest body of ice.A research team, led by scientists from Durham University using 3-D surface maps, found crevasses had “significantly increased” in both size and depth at the fast-flowing edges of the ice sheet between 2016 and 2021.They say their findings, published in the journal Nature Geoscience, show that 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 research team says that crevasses are also getting bigger and deeper where ice is flowing more quickly due to climate change.They warned that it could further speed up the mechanisms behind the loss of ice from Greenland.The team hopes their findings will allow scientists to build the effects of ice damage and crevassing into predictions of the future behavior of the Greenland Ice Sheet.Previous research has shown that Greenland has been behind around 14mm (0.55 inches) of sea level rise since 1992.That 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 meters (23 feet) 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 (12 inches) to sea level rise by 2100.For the new study, the research team used more than 8,000 3-D surface maps, created from high-resolution satellite imagery, to identify cracks in the surface of the ice sheet and show how crevasses had evolved across Greenland between 2016 and 2021.The findings showed 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 of up to 25% in some sectors.The 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.The researchers say that balanced the total change in crevasses across the entire ice sheet during the study period to plus 4.3%.But 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.Study lead author Dr Tom Chudley, of Durham University’s Department of Geography, 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 deeper into the ice.”However, until now we haven’t had th
Lun. Feb 3rd, 2025
