A 76.4-square-kilometer ice island has detached from northwestern Greenland's Petermann Glacier, marking the largest Arctic ice loss since 2020.
The massive floating ice mass separated from the glacier's ice tongue on August 4, 2026, creating a tabular iceberg that could reach up to 150 meters in thickness.
An international team of researchers confirmed that the event represents the largest single loss of floating ice recorded in Greenland since 2012, as well as the largest Arctic ice detachment in six years.
Spanning an area comparable to the island of Manhattan, the giant ice structure offers scientists a rare opportunity to monitor the life cycle of a large Arctic ice mass from its initial formation to its eventual fragmentation.
Satellite observations had shown growing signs of structural instability along the glacier for years prior to the break. Monitoring conducted since 2019 documented expanding cracks and structural changes across the floating ice tongue.
Adam Garbo, a researcher at the Department of Geography, Environment and Geomatics at the University of Ottawa, said Petermann had long been one of the largest remaining ice tongues in Greenland. He explained that researchers had anticipated the detachment for years, adding that watching it finally happen was extraordinary.
Satellite images capture calving event
Radar imagery gathered by the European Space Agency's Sentinel-1 satellite mission revealed clear structural weakening along the central line of the ice tongue on August 3. By 20:00 UTC on August 4, the ice island had completely detached from the glacier's eastern sector.
The Sentinel-1 mission uses synthetic aperture radar to monitor Earth's surface through clouds and polar darkness. Greenland, an autonomous territory of Denmark situated between the Arctic and Atlantic oceans, holds the northern hemisphere's largest ice sheet, making space-based radar tracking vital for observing remote polar glaciers.
Dr. Anna Crawford, a glaciologist at the University of Stirling, noted that while large tabular icebergs are relatively common in the Southern Ocean surrounding Antarctica, Arctic ice islands of this scale are far rarer. She said studying Arctic ice islands provides insights that can be applied across other polar regions.
Unlike smaller icebergs, massive tabular ice islands can persist for years in freezing ocean waters. Their longevity allows scientists to study ocean conditions, glacier retreat dynamics, and navigation risks in polar maritime routes.
Two more large ice islands expected to break away
Researchers warn that the August calving may be the start of a broader series of structural collapses. Scientists consider it likely that two additional large ice islands will separate from the Petermann Glacier in the near future if existing fissures continue to expand across the floating tongue.
If those two sections break off, they are expected to form ice islands measuring approximately 94 square kilometers and 84 square kilometers. Combined with the recently detached mass, the total loss would reach 254 square kilometers, representing roughly 22 percent of the Petermann Glacier's floating ice tongue.
Glaciologists and satellite teams will continue tracking the region using satellite data and aerial photography to monitor the newly formed ice island and assess the potential impact of further detachments.
