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Greenland Ice Sheet Faces Accelerated Crevassing and Impacts on Sea Levels
In a significant finding, researchers have recorded the emergence of 930 million cubic meters of crevasses in the Greenland ice sheet over a mere five years. This dramatic alteration is comparable to adding a crack the size of the Great Pyramid of Giza to the world’s second largest ice sheet approximately every few days.
The observed crevasses, particularly prevalent in areas where the ice flows rapidly, pose the risk of initiating a feedback loop that could further expedite the melting of glaciers. Such accelerated ice loss contributes to rising sea levels, with Greenland’s melt contributing approximately 0.4 inches to global sea levels since 1992. Projections suggest that by the century’s end, this could increase by an additional foot.
The study, conducted by a collaborative team from the University of Florida, Durham University in the UK, and other institutions, analyzed the Greenland ice sheet between 2016 and 2021. It represents the first comprehensive ice-sheet-scale assessment of crevasses spanning multiple years, allowing researchers to observe changes over relatively brief timeframes.
To effectively study crevasse behavior throughout the extensive expanse of the Greenland ice sheet, the research team adopted innovative methodologies. “It’s not feasible to conduct in-person studies due to the hazards associated with crevasses. Traditional satellite analysis is also not sufficient; therefore, automated techniques are essential for examining these features on an ice-sheet scale,” remarked Dr. Emma MacKie, a professor of geological sciences at the University of Florida and a co-author of the study, who specializes in machine learning approaches.
The research consortium, which included experts from Ohio State University and the University of Washington, created an automated system for detecting and measuring crevasses. This system utilized three-dimensional satellite imagery supplied by the Polar Geospatial Center.
While the overarching trend indicates an increase in crevassing throughout Greenland, the data revealed variability across different glacier regions. Notably, one section on the western side of Greenland exhibited a decrease in crevasse volume during the study period. However, this regional decline was overshadowed by substantial increases—up to 25%—in crevasse volume in other parts of the glacier, indicating widespread change.
Recent observations suggest that the western region has begun to experience newfound cracking, suggesting that further crevassing across the entire ice sheet may be anticipated in the near future.
“Crevasses can lead to accelerated ice flow, which in turn may cause even more crevassing to occur. This creates potential positive feedback loops driven by the presence of crevasses,” said MacKie. “These dynamics should be integrated into models of the Greenland ice sheet as they are essential for predicting future sea level rise.”
This important research received partial funding from the National Aeronautics and Space Administration and the National Science Foundation.
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