A landmass that was previously encased in the ice of Alaska's Alsek Glacier is now fully surrounded by water, forming a new island in the state, NASA satellite images reveal.

The nearly two-square-mile landmass was left surrounded by the waters of Alsek Lake after the glacier of the same name, which once encircled a small mountain known as Prow Knob near its terminus, lost contact with the mountain this summer.

The pair of images (shown in a comparison below), taken by NASA's Landsat satellites, show the extent of ice retreat and lake growth between July 5, 1984 and August 6, 2025.

The separation between the glacier and Prow Knob happened sometime between July 13 and August 6 this summer, according to the satellite imagery.

Water is rapidly replacing ice along the coastal plain of so

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