An Unusual Drifter in the Denmark Strait

Greenland's rugged coastline is dotted with fjords, many of which are home to glaciers that frequently calve icebergs into the ocean. In the summer of 2026, an exceptionally large iceberg was observed in the Denmark Strait, an area far south of its likely origin.

Captured by the Operational Land Imager (OLI) on Landsat 9, these images show the iceberg on June 12 as it journeyed through the strait separating Greenland and Iceland. It was located just south of Kangikajiip Appalia, a prominent cape on Greenland's eastern coast, amidst a mixture of sea ice and smaller ice fragments, a phenomenon known as "mélange."

According to Alexis Denton, an oceanographer and chief scientist with the International Ice Patrol, several factors suggest this is indeed an iceberg rather than thick, multi-year sea ice. These include its proximity to the shore, its distinct white color, and its substantial size compared to the surrounding sea ice. On June 12, the iceberg measured approximately 17 square kilometers (7 square miles), an area roughly five times that of New York City's Central Park. While modest in size compared to the massive icebergs from Antarctic glaciers, it was considered quite large for Greenland.

Keld Quistgaard, a senior ice advisor with the Greenland Ice Service of the Danish Meteorological Institute, indicated that the iceberg likely originated from Jøkelbugten, a bay in northeastern Greenland. However, its precise origin within that bay remains somewhat unclear. It is possible that the berg detached from the Zachariæ Isstrøm glacier or its adjacent remnant ice shelf. This ice shelf, along with Zachariæ Isstrøm, once filled the bay but was abandoned after the glacier's rapid retreat in the early 2000s.

Tracing the iceberg's path through satellite imagery presents challenges. Throughout the spring, the bay and surrounding coastal regions are densely packed with sea ice and iceberg fragments, making it difficult to distinguish individual bergs, especially if they are covered in snow. In late May, for example, the iceberg was surrounded by numerous similar-looking ice formations. It only became distinct enough to be easily spotted later in the season as it drifted further south and the surrounding ice thinned.

The iceberg's size and the intricate network of blue meltwater ponds on its surface offer additional clues about its origin, according to Christopher Shuman, a retired glaciologist from the University of Maryland. Shuman believes the berg calved from the remnant ice shelf rather than the glacier itself, noting that icebergs from Zachariæ Isstrøm tend to be smaller. Furthermore, the iceberg's surface, pockmarked with meltwater ponds, closely resembles the remnant shelf ice. Past satellite images have shown pieces of this shelf ice drifting south and becoming trapped among islands bordering the bay, where they have been subjected to years of jostling by winds and tides.

By mid-August, the iceberg had traveled approximately 1,500 kilometers (900 miles) south from its origin bay, carried by the Greenland Coastal Current into the North Atlantic. Quistgaard anticipated that the iceberg would gradually disintegrate throughout the month, a process that recent satellite imagery suggested was underway.

Breaking up in the Denmark Strait means that remnants of the iceberg are unlikely to drift into busy shipping lanes south of Greenland. Shuman commented that its journey serves as a reminder of Earth's dynamic nature and the seasonal variability of ice in this part of the North Atlantic.