ALASKA: NASA has uncovered a new island off the coast of Alaska, revealed by satellite imagery as a result of a melting glacier. The island emerged when the Alsek Glacier receded, isolating a small mountain once part of the mainland.
The island, located in Alsek Lake, was previously engulfed by the Alsek Glacier, which has been thinning over time. The most recent satellite images, captured on August 6, 2025, show the glacier’s retreat and the transformation of a previously connected mountain, Prow Knob, into an island.
NASA’s images from July 5, 1984, and August 6, 2025, show the glacier’s retreat by over five kilometers, creating a proglacial lake. The glacier’s separation from Prow Knob officially classifies it as an island. The retreat of Alsek Glacier has also led to the expansion of Alsek Lake, which has grown from 45 square kilometers in 1984 to 75 square kilometers today.
Scientists suggest the newly formed island covers about five square kilometers, and satellite data indicates it emerged between July 13 and August 6. The retreat of Prow Knob has made the glacier more unstable, increasing the risk of calving, where large chunks of ice break off and fall into the lake.
This discovery provides new insights into the ongoing effects of climate change and glacier retreat in the region.
