Greenland Iceberg Survives Collision with Joe Island

A large iceberg, measuring over 76 square kilometers, broke from Greenland’s Petermann Glacier in August 2026. This event marked the Arctic’s largest glacier calving since 2020. The iceberg later collided with Joe Island but remained intact. Satellites are currently tracking its movement through Nares Strait.

Iceberg calving is a natural process for outlet glaciers. Scientists monitor these events for signs of instability. Petermann Glacier is one of Greenland's largest marine-terminating glaciers. It influences the flow of ice from the Greenland Ice Sheet into the ocean. Changes in its stability could affect sea level rise.

The calving event was first identified on August 4 by Adam Garbo, a glaciology doctoral student at the University of Ottawa. He used imagery from the European Space Agency’s Sentinel-1 mission. The ice island measured over 76 square kilometers when it separated from the glacier. This made it the largest iceberg to break from Petermann since 2012.

Glaciologist Mauri Pelto of Nichols College also tracked the iceberg using National Aeronautics and Space Administration (NASA)-United States Geological Survey (USGS) Landsat satellites. After detaching, the berg moved down Petermann Fjord at approximately three kilometers per day. It then approached the point where the fjord meets Nares Strait. The iceberg collided with Joe Island, a small rocky outcrop.

The collision was captured by the Operational Land Imager (OLI) aboard Landsat 9 on August 23 and August 24. Icebergs from Petermann are generally thinner and more fragile than those from other Greenland glaciers. Despite this, the new ice island remained intact after striking Joe Island. Researchers were surprised it survived the interaction without fragmenting.

Winds and surface currents carried the iceberg out of Petermann Fjord. Satellite observations showed it pivoting away from Joe Island. It then moved southwest through Nares Strait. The iceberg will gradually weaken due to tides, winds, ocean currents, and melting. Eventually, it will fracture into smaller pieces. These fragments can travel long distances, creating hazards for ships and releasing freshwater into Arctic waters.