Giant Petermann Glacier iceberg collides with Joe Island and stays intact

In early August, a colossal iceberg—about the size of St. Thomas in the U.S. Virgin Islands—calved from Greenland’s Petermann Glacier, marking the Arctic’s biggest glacier break since 2020. The ice island, identified by Adam Garbo of the University of Ottawa via Sentinel-1 imagery, covered just over 76 square kilometres and was less than 150 metres thick. It traveled down Petermann Fjord at roughly 3 km per day, reaching the entrance of Nares Strait where it collided with the small rocky formation Joe Island, an event recorded by Landsat 9’s Operational Land Imager on August 23-24.

Unlike a similar 2010 impact that split an iceberg, this one stayed intact, surprising glaciologists Mauri Pelto of Nichols College and his colleagues. The berg now pivots southwest through Nares Strait, where ongoing oceanic forces will gradually weaken it until it fragments. Such ice islands can travel far, posing navigation hazards and delivering fresh meltwater that influences Arctic marine environments.