Glacial Dam Outburst Devastates Juneau, Alaska

Over 100 homes in Juneau, Alaska, have been damaged due to a glacial dam outburst caused by the retreating Mendenhall Glacier. The flooding, driven by climate change, began Monday night and crested early Tuesday morning. Authorities had to shelter residents as similar outbursts have become more frequent over recent years.

More than 100 homes in Juneau, Alaska, have suffered damage from a glacial dam outburst north of the city, a phenomenon increasingly aggravated by climate change. The flooding began on Monday night after the glacial lake at Suicide Basin overflowed, typically held in check by the retreating Mendenhall Glacier. When the basin fills with enough water, it can overflow or breach the ice dam holding it.

The overflow peak occurred at around 3 a.m. on Tuesday, with the Mendenhall River reaching a height of 15.99 feet, according to the National Weather Service. By Wednesday, the river had returned to its normal levels. Local authorities had already warned nearby residents to take necessary precautions and opened a local school as a shelter. City officials confirmed no injuries have been reported.

This event came almost a year after a record-breaking glacial dam outburst at Suicide Basin caused similar flooding. In 2023, the Mendenhall River crested at 14.82 feet, as recorded by the National Weather Service. Man-made climate change has heightened the risk of such events by causing glaciers to retreat, leading to more and larger glacial lakes.

The U.S. Geological Survey has been monitoring Suicide Basin since 1965, but the first recorded glacial dam outburst did not occur until July 2011. Since then, the basin has burst more than 30 times, the National Weather Service reported.