{"id":2495,"date":"2026-09-30T07:27:22","date_gmt":"2026-09-30T07:27:22","guid":{"rendered":"https:\/\/flatplanplus.io\/bbc-wildlife\/?p=2495"},"modified":"2026-09-30T07:27:22","modified_gmt":"2026-09-30T07:27:22","slug":"petermann-ice-shelf-estuary","status":"publish","type":"post","link":"https:\/\/flatplanplus.io\/bbc-wildlife\/2026\/09\/30\/petermann-ice-shelf-estuary\/","title":{"rendered":"Manhattan-sized iceberg breaks free in Greenland. What caused the event has never been seen before"},"content":{"rendered":"\n
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Wildlife<\/p>\n\n\n\n

Manhattan-sized iceberg breaks free in Greenland. What caused the event has never been seen before<\/strong><\/h1>\n\n\n\n

The Petermann Ice Shelf in northern Greenland just experienced its largest calving event since 2020 \u2013 here’s what caused it.<\/h2>\n\n\n\n
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Words by<\/em> Will Newton<\/p>\n\n\n\n

September 30th, 2026<\/p>\n<\/div>\n<\/div>\n\n\n\n

\"Iceberg\"
Credit: Grafissimo\/Getty Images<\/em><\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

A new study on an ice shelf estuary on the Petermann Ice Shelf \u2013 the first known estuary of its kind \u2013 has found this brackish body of water may be to blame for the glacier\u2019s recent iceberg breakaway. <\/strong><\/p>\n\n\n\n

By applying modern methods to years of ocean measurements and satellite images, scientists have revealed how and when the estuary formed.<\/p>\n\n\n\n

The Petermann Ice Shelf in northern Greenland<\/a> connects the wider Greenland Ice Sheet to the Arctic Ocean. On August 4, 2026, an iceberg<\/a> the size of Manhattan, New York City, broke away from the ice shelf, marking the glacier\u2019s largest loss of floating ice since 2012 and the largest calving event since 2020. <\/p>\n\n\n\n

In 2021, shortly after the glacier\u2019s last major calving event, a NASA-funded team of scientists discovered an ice shelf estuary using high-resolution satellite imagery. The estuary was the first of its kind found anywhere in the world, prompting the team to investigate it further.<\/p>\n\n\n\n

The first study on this ice shelf estuary, published in Nature Geoscience<\/em> in 2021, revealed that such bodies of water promote fractures and calving, but it wasn\u2019t until the latest study led by scientists from the Cooperative Institute for Research in Environmental Sciences (CIRES), published recently in The Cryosphere<\/a><\/em>, that the behaviour of the estuary was able to be properly measured.<\/p>\n\n\n\n

\u201cFor the first time, we were able to measure how quickly the river cut into the ice shelf to form the estuary, which revealed more complex estuary behaviour than was previously suggested,\u201d said the study\u2019s lead author, Michela Savignano. \u201cWe did this using a new method for calculating elevation of the river channel above sea level during the melt season from satellite imagery.\u201d<\/p>\n\n\n\n