NASA satellites spot brand-new island in Alaska formed by melting glacier (photos)

Alaska's Alsek Glacier has retreated more than 3 miles (5 kilometers) since 1984, turning Prow Knob into an island. (Image credit: NASA Earth Observatory images by Michala Garrison, using Landsat data from the U.S. Geological Survey.)

NASA satellite imagery has revealed a new island off Alaska's coast that emerged after long-standing glacial ice melted, isolating a small mountain that was once part of the mainland.

The island sits in Alsek Lake, where the Alsek Glacier has been steadily thinning and flooding the region with meltwater. Two Landsat images — captured on July 5, 1984 by the TM (Thematic Mapper) on Landsat 5 and on Aug. 6, 2025 by the OLI-2 (Operational Land Imager-2) on Landsat 9 — show the transformation in striking detail, according to a statement from NASA.