A 76-square-kilometer iceberg calved from Greenland's Petermann Glacier in August 2026 and survived a collision with a rocky island as it drifted into Nares Strait.
NASA reported that the tabular ice island broke away along the northwest coast of Greenland, marking the Arctic's largest calving event since 2020. The slab of ice measures roughly 29 square miles, approximately the size of St. Thomas in the U.S. Virgin Islands, and was estimated to be less than 150 meters thick when it separated.
Adam Garbo, a doctoral student in glaciology at the University of Ottawa, first spotted the detachment on August 4 using imagery from the European Space Agency's Sentinel-1 mission. Garbo and an international research team had monitored rifts across Petermann's ice tongue and anticipated a break. “What surprised us was that the calving instead followed a different fracture, producing a smaller ice island than we had originally anticipated,” Garbo said. Two separate rifts remain intact, which scientists expect will eventually generate additional ice islands measuring approximately 94 and 84 square kilometers.
Mauri Pelto, a glaciologist at Nichols College, tracked the berg's progression down Petermann Fjord using images from NASA-USGS Landsat satellites. The ice drifted at an average speed of three kilometers per day before striking Joe Island, a small rocky outcrop positioned at the mouth of the fjord. Collisions at the outcrop routinely shatter exiting ice; a similar impact in 2010 split an ice island in two.
The 2026 ice island remained intact despite the impact. “We were certainly watching closely as it interacted with Joe Island and were impressed that it survived the interaction without further fragmentation,” Garbo said. Petermann bergs are thinner and more fragile than ice calved by Greenland’s Jakobshavn and Helheim glaciers or Antarctic glaciers, Pelto noted.
Operational Land Imager data from the Landsat 9 satellite captured the iceberg pivoting away from Joe Island on August 23 and August 24 as wind and currents pushed it southwest into Nares Strait. The research team noted that such ice islands can travel long distances, distribute freshwater across the ocean as they melt, and create navigation hazards for marine operations before running aground or breaking apart.
