Plate Nº 75 · recorded October 13, 2026
Earth & ClimateReported finding
Petermann Glacier Loses 76-Square-Kilometer Iceberg in August 2026
Adam Garbo's team identified a 76-square-kilometer berg breaking from Petermann Glacier on August 4, 2026. It slammed Joe Island on August 23-24 and survived intact.
By Marcus Bennett3 min read639 words
In brief
- A 76-square-kilometer iceberg broke from Petermann Glacier on August 4, 2026 — the largest Arctic calving since 2020.
- Two rifts remain on the ice tongue; researchers expect future ice islands of about 94 sq km and 84 sq km.
- Landsat 9 captured the berg striking Joe Island on August 23-24, 2026; the berg remained intact.
- Garbo of the University of Ottawa identified the calving with Sentinel-1; Pelto of Nichols College tracked it with Landsat.
- The berg measured less than 150 m thick at calving and moved roughly 3 km per day during its first week.
A 76-square-kilometer iceberg broke free from Greenland's Petermann Glacier on August 4, 2026 — the Arctic's largest glacier calving event since 2020 and the biggest from Petermann since a 130-square-kilometer break in 2012.
The flat-topped berg, what glaciologists call an ice island, measures just over 29 square miles. Adam Garbo, a doctoral student in glaciology at the University of Ottawa, identified the calving first in imagery from the European Space Agency's Sentinel-1 mission.
Garbo's international team has tracked Petermann's floating ice tongue by satellite for years. The Petermann floating tongue helps control how fast ice from the Greenland Ice Sheet drains into the sea, so every fracture draws attention.
In plain words: Calving is routine; the size and the timing of this one set it apart.
What surprised the research team?
Researchers were watching a major rift they expected to slice across the tongue and release an even larger berg. Instead, the glacier fractured along a different crack.
"What surprised us was that the calving instead followed a different fracture, producing a smaller ice island than we had originally anticipated," Garbo said.
For context, Petermann has produced sizable ice islands several times this century: roughly 31 square kilometers in 2008 and just over 250 square kilometers in 2010. The August 4 break slots between those markers.
Two large rifts remain. Garbo's group expects them eventually to release new ice islands of about 94 square kilometers and 84 square kilometers, though timing remains uncertain.
In plain words: A different crack meant a smaller berg; the next cracks are already mapped.
What happens when an iceberg meets Joe Island?
After separating, the new berg moved down Petermann Fjord at an average of about 3 kilometers per day during its first week. It reached the fjord mouth, where a small rocky outcrop called Joe Island (Joe Ø) sits directly in the path of departing ice islands.
Glaciologist Mauri Pelto of Nichols College tracked the approach with NASA-USGS Landsat satellites. The Operational Land Imager aboard Landsat 9 captured the collision on August 23 and August 24.
Past collisions have not been gentle. A 2010 ice island from Petermann struck Joe Island and split into two pieces. Pelto noted that Petermann bergs are generally thinner and more fragile than those from Jakobshavn or Helheim, and far thinner than Antarctic icebergs.
In plain words: Joe Island has broken others before; thin ice and hard rock usually do not mix.
Why did this one survive?
Despite that fragility, the August ice island remained whole.
"We were certainly watching closely as it interacted with Joe Island and were impressed that it survived the interaction without further fragmentation," Garbo said.
At calving, the ice island stood less than 150 meters thick. Winds and surface currents then pushed it out of the fjord. Satellite scenes show it pivoting away from Joe Island and moving southwest through Nares Strait.
In plain words: Survival this time owed more to geometry than to strength — the berg slid past the rock rather than into it.
Where does the berg go next?
Tides, winds, ocean currents, and melting will gradually wear the berg down until it fractures. Unlike thicker icebergs from tidewater glaciers without floating shelves, Petermann ice islands often travel farther before running aground. Many eventually ground near Coburg Island or Baffin Island.
The bergs also seed hazards for ships and offshore infrastructure as they drift. As they melt, they release freshwater that carries the climate influence of the Greenland Ice Sheet far past the fjord mouth.
Garbo's team continues to monitor the berg through daily Sentinel-1 passes, watching for the first signs of the break they still expect.
In plain words: The end will come in fragments; the question now is when, and how far it travels first.
via glacierchange.blog (Original)
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News editor covering regulation, policy and their impact on general science news at SciBeat.
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