Alaska’s capital, Juneau, is facing a serious flood threat from the Mendenhall Glacier. The glacier has created a dam that holds back a lake, and due to climate change, the ice is melting faster. This summer, heavy rain and snowmelt are causing worries of a glacial lake outburst flood, or GLOF.
Authorities predict the floodwaters will reach their peak around 4 PM local time on Wednesday. They have set up emergency barriers to protect the Mendenhall Valley, which is home to most of Juneau’s 32,000 residents. As water began leaking from the ice dam on Tuesday morning, officials urged residents to evacuate quickly.
In a recent update, the National Weather Service (NWS) forecasted the Mendenhall River could crest at over 16 feet on Wednesday. Nicole Ferrin from the NWS mentioned that the situation is complicated by rainfall and the rapid rise in water levels. “This will be a new record based on all of the data we have,” she said.
The Mendenhall Glacier occupies a large valley to the north of Juneau, creating a lake in Suicide Basin that fills with meltwater. Since 2011, outburst floods from this area have become an annual event, threatening the city more each year as climate change accelerates glacial melting. The National Oceanic and Atmospheric Administration (NOAA) states that Alaska is warming twice as fast as the rest of the U.S. In the last century, average temperatures have risen by 3.1 degrees Fahrenheit.
Rick Thoman, a climate specialist, emphasized that these flooding events are closely linked to climate change. “Without climate change, there is no reason to think this would be happening,” he noted. Indeed, recent floods have impacted areas not previously affected, causing significant erosion and damage.
Historically, the Mendenhall Glacier has been a popular destination and a significant feature in the landscape, known to the Tlingit people as Sitaantaagu or Aak’wtaaksit before being renamed in the 1890s. The glacier’s retreat is a stark reminder of the changing climate, receding nearly 100 to 150 feet each year.
As scientists continue to study these patterns, summer floods become a growing concern. The looming threat in Juneau serves as a wake-up call about the effects of climate change and the urgency it calls for in mitigation efforts.
For more information on climate impacts, you can refer to NOAA’s extensive research on climate trends here.
