Ice sheet melting from Greenland’s glaciers accounts for an increasing proportion of global sea level rise, losing ~330 billion tonnes of ice per year during 2006-2018 (compared to ~120 billion tonnes of ice per year during 1901-1990). A new study published in Nature Communications examined recent changes at K.I.V Steenstrups Nordre Bræ (66.53°N, 34.57°W), a glacier in the southeast Greenland Ice Sheet that exhibited long-term stability since the cartographic records started in the late 1930s. The study found that Steenstrups retreated ~7 km, thinned ~20%, and doubled in ice discharge between 2018 and 2021. Due to this unprecedented change, Steenstrups is now placed in the top 10% most rapidly melting Greenland glaciers. The study also found that Steenstrup was largely insensitive to high sea surface temperatures in 2016 that destabilised many neighboring glaciers. Instead, it responded to an enhanced intrusion of Atlantic deep water in 2018, which resulted in a >2°C anomaly around its sill depth (~ 180 m). This indicates that warm Atlantic deep water intrusion to the sill depth of the southeast Greenland Ice Sheet has exceeded the local temperature threshold (~ 2°C anomaly) for the first time since the late 1930s. The study highlights that even long-term stable Greenland glaciers are vulnerable to increasingly warm Atlantic deep water intrusion to their sill depth.
Image Credit: https://www.climate.gov/media/14169
Chudley, T.R., Howat, I.M., King, M.D. et al. (2023). Atlantic water intrusion triggers rapid retreat and regime change at previously stable Greenland glacier. Nature Communications, 14, 2151. https://doi.org/10.1038/s41467-023-37764-7
Ocean to Climate 
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