Alsek Glacier Retreat Creates New Island in Alaska

A new island, named Prow Knob, has emerged in Glacier Bay National Park, Alaska, after the Alsek Glacier retreated and lost contact with the landmass due to rapid glacial melting driven by climate change. Satellite images from NASA’s Landsat 9 show that this roughly 2-square-mile mountain, previously surrounded by ice, became fully isolated between July and August 2025, marking a significant transformation in the region's landscape. This change exemplifies the broader pattern of glacier thinning and retreat in southeastern Alaska, where warming temperatures have caused glaciers to melt, forming larger proglacial lakes such as Alsek Lake, which nearly doubled in size since 1984. Scientists highlight that the retreat of glaciers and formation of new islands have practical impacts on local hydrology and ecosystems, underscoring the accelerating effects of global warming. Observations dating back to the early 20th century document the glacier’s steady recession, with Prow Knob once encased by ice faces up to 50 meters high. NASA Earth Observatory science writer Lindsey Doermann emphasized that water is rapidly replacing ice along Alaska's coastal plain, demonstrating the ongoing and visible consequences of human-caused climate change.