Feb 15 2018

Scientists monitor glacial lakes to prepare for outburst floods in Alaska

By: Lindsey Heaney

Mendenhall glacier sits roughly 12 miles north of Juneau, Alaska. It’s the only barrier between the Suicide Basin sub-glacial lake and hundreds of residents as well as the critical infrastructure that serves over 32,000 people. In 2011 and 2014, Suicide Basin broke its ice barrier and an outburst flood destroyed nearby trails and property. Since then, these events have been increasing, which causes a significant threat to downstream infrastructure and public safety.

AK CASC scientists Gabriel Wolken (UAF) and Eran Hood (UAS) are studying these outburst events near Juneau. Wolken, who also manages the Climate and Cryosphere Hazards Program at the Alaska Division of Geological & Geophysical Surveys, works with Katreen Wikstrom Jones to monitor Glacial Lake Outburst Floods (GLOFs) at other locations in Alaska.

Water that runs over, under, and through glaciers due to rain or glacial melt, sometimes gets dammed by glacial ice. The volume of water stored behind the ice-dammed lake increases until the dam is breached, usually resulting in a catastrophic release of water that can flood downstream rivers.

“This can be very serious and can cause a lot of damage to the surrounding landscape and to the local communities downstream,” says Wolken.

The team gathers their data through real-time monitoring by strategically placing cameras and other measuring equipment around threatening ice-dammed lakes in Alaska.

These include Bear Glacier in the Kenai Mountains, Russell Lake at Hubbard Glacier in the Saint Elias Mountains, Valdez Glacier in the Chugach Mountains, and Suicide Basin at Mendenhall Glacier in the Coast Range.

At each of these four sites, the team surveys the area along with reviewing real-time camera footage and water level gages. These tools allow them to evaluate how much water is being held and determine the outburst risk.

“Often times we can actually see the water level decrease in our recordings and that’s when we know that an outburst is happening or is about to occur,” explains Wolken.

In the event of an outburst, the team uses their monitoring tools to study outbursts in real-time in order to better understand the glacial system and to warn communities as quickly as possible.

“These tools not only allow us to gather data on what’s happening with these glacial lakes, but also to warn authorities if there is a possible danger of an outburst,” says Wikstrom Jones.

With Alaska being home to many glacial lakes and a shift in climate causing more permafrost thaw and ice melt, the team of glaciologists expect these outburst floods to occur more often. Through their monitoring and co-production, Wolken believes this project is essential to keeping residents of Alaska aware and better prepared.

“Having a team based on co-production has really allowed this project to not only move the science forward, but also help to make the state more prepared for these destructive events in the future,” he says.

To learn more about this project and to see the latest data gathered, please visit the Glacier Lake Outburst Floods in Alaska Story Map