Overview

• Landsat 9 images indicate the final ice contact withdrew between July 13 and August 6, confirming full isolation of Prow Knob in Alsek Lake.
• The exposed landmass is about 2 square miles within Glacier Bay National Park and Preserve, with a summit just over 1,000 feet.
• Alsek Lake has expanded from roughly 45 to about 75 square kilometers since 1984 as regional glaciers have retreated.
• Glaciologist Mauri Pelto, who has monitored the site for years, says islands of this size from glacier retreat are rare in Alaska this century.
• Researchers warn the detachment raises the likelihood of calving and related hazards in proglacial lakes as retreat continues.