Juneau’s flooded Mendenhall Valley is seen on Aug. 7, 2024. The waters pouring from an outburst flood at Mendenhall Glacier reached record levels, surpassing the record set by a similar glacial outburst flood the previous year. Hundreds of homes were damaged, and some were destroyed. (Photo provided by the City and Borough of Juneau)
After two consecutive years when meltwaters burst out of a basin on Juneau’s Mendenhall Glacier and devastated neighborhoods in that part of the capital city, a team of scientists has received a grant of nearly $1 million to assess the hazards that could produce repeat occurrences.
The National Science Foundation awarded $990,437 for a five-year project to be conducted by scientists from the University of Alaska Southeast, the University of Alaska Fairbanks and Carnegie Mellon University.
Researchers will examine the way the glacier, a prominent feature in Juneau’s landscape, has changed over the years and how those changes affect flood dynamics, a UAS statement said. The ultimate product is to be a set of tools to improve glacial flood forecasts in Juneau and elsewhere, the university statement said.
“We have been investigating the Mendenhall Glacier outburst floods for over 10 years, but with minimal support. This grant will greatly enhance our ability to improve flood forecasts, assess the outburst flood hazard over the coming years and decades, and inform engineering solutions. We look forward to continuing our work with local, state, and federal partners, and to developing new partnerships with tribal organizations,” Jason Amundson, a UAS geophysics professor and the project’s principal investigator, said in the statement.
The past two years’ floods were record-breaking events. The Mendenhall River crested at 14.97 feet in 2023, a record that was broken the following year when the river crested at 15.99 feet, according to the U.S. Geological Survey.
They could not have happened but for climate change, which has accelerated the melt of Mendenhall Glacier, said scientists at UAF and the National Oceanic and Atmospheric Administration.
The floods damaged hundreds of homes, completely destroying some. Government officials issued disaster declarations both in 2023 and in 2024.
Such glacial outburst floods are relatively recent events at Juneau’s Mendenhall Glacier. The first recorded outburst flood there was in 2011, according to officials.
The volume of water released from the basin has increased since 2011, and especially in the last two years, said Eran Hood, a UAS environmental science professor who is part of the research team. “However, there is a lot of variability so there is not a trend in the sense of a year over year increase in flood volume,” he said by email.
Juneau is not the only Alaska site susceptible to glacial outburst floods. Several other sites have experienced such floods, including the Snow River outside of Seward on the Kenai Peninsula.
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