A massive iceberg, larger than 76 square kilometers, broke off Greenland’s Petermann Glacier in August 2026, marking the largest glacier calving event in the Arctic since 2020. Calving is the process by which chunks of ice break away from glaciers or ice shelves, often due to natural fractures or environmental changes. This particular iceberg, known as an "ice island," separated from the glacier and later collided with a small rocky island called Joe Island. Despite the impact, the iceberg remained intact and is now drifting through Nares Strait, a narrow waterway between Greenland and Canada’s Ellesmere Island. The calving event was first noticed by Adam Garbo, a doctoral student in glaciology at the University of Ottawa, who used satellite imagery from the European Space Agency's Sentinel-1 mission. The iceberg is the largest to break from Petermann since a 2012 event that produced an ice island of 130 square kilometers. Previous major calving events occurred in 2008 and 2010, producing ice islands of 31 and 250 square kilometers, respectively. Scientists had been expecting an even larger break, but the glacier fractured along a different crack than anticipated, resulting in a smaller ice island than originally predicted. As of late August, two large rifts remained in the glacier, and researchers expect them to eventually release new ice islands of about 94 and 84 square kilometers. After breaking away, the iceberg moved down Petermann Fjord toward Nares Strait at an average speed of about 3 kilometers per day during its first week. It eventually reached the point where the fjord meets Nares Strait and collided with Joe Island. This event was captured by the Operational Land Imager (OLI) aboard the Landsat 9 satellite on August 23 and 24. Joe Island is located near the entrance of Petermann Fjord, a common path for ice islands leaving the glacier. While such collisions can sometimes cause icebergs to break apart, this new iceberg remained intact after the impact. The ice island was estimated to be less than 150 meters thick when it broke away. Winds and ocean currents carried it out of Petermann Fjord, and satellite observations showed it pivoting away from Joe Island and moving southwest through Nares Strait. Over time, tides, melting, and ocean forces will gradually weaken the iceberg until it eventually fractures into smaller pieces. Icebergs from Petermann tend to travel farther before running aground compared to thicker icebergs from other glaciers. Many eventually become "grounded" near the coasts of Coburg and Baffin islands. While they pose navigational hazards, they also play a role in the ocean by releasing freshwater as they melt, influencing surrounding waters far from the fjord.