As climate change is causing ocean temperatures to rise, one of Greenland’s previously most stable glaciers is now retreating at an unprecedented rate, according to a new study. The team, led by Ohio State University researchers, found that between 2018 and 2021, Greenland’s Steenstrup Glacier retreated about 5 miles, thinned about 20%, doubled the amount of ice poured into the ocean, and quadrupled its speed.

This rapid change is so unusual among Greenland’s ice formations that it places Steenstrup in the top 10% of glaciers currently contributing to total ice loss in the region, according to the study. Study published Nature Communication.

The Steenstrup Glacier is part of the Greenland Ice Sheet, an ice mass that covers about 80% of the world’s largest island, and is also the largest source of global sea level rise from the cryosphere, the entire Earth’s ecosystem. frozen water. While the region plays a critical role in stabilizing the global climate system, the area is shrinking as hundreds of billions of tons of ice are shed each year due to global warming.

Over the past few decades, much of this loss has been attributed to rapidly released ice from tidewater glaciers, which are glaciers in contact with the ocean. Many glaciologists believe that this recent increase in ice shedding can be explained by the intrusion of warm waters from the Atlantic into Greenland’s fjords – critical ocean passages that can affect the stability of local glaciers and the health of polar ecosystems.

The research team aimed to test this theory by examining a glacier in southeastern Greenland called KIV Steenstrups Nordre Bræ, popularly known as the Steenstrup Glacier.

“Until 2016, there was nothing to suggest that Steenstrup was interesting in any way,” said study lead author Thomas Chudley, who completed the study as a research associate at the Byrd Center for Polar and Climate Studies. Chudley is currently a Leverhulme Research Fellow at Durham University, UK. “There have been many other glaciers in Greenland that have retreated dramatically since the 1990s, increasing their contribution to sea level rise, but this was not one of them.”

As far as scientists know, Steenstrup has not only been stable for decades, but also largely insensitive to the warming that has destabilized many other regional glaciers, possibly due to its isolated location in shallow water. Until Chudley and colleagues compiled observational and modeling data from previous remote-sensing analyzes of the glacier, the team realized that Steenstrup was likely melting due to anomalies in deeper Atlantic waters.