Rapid glacier melting near Juneau results in yearly flooding becoming the prevailing condition - momentarily.
A glacial outburst flood hit Juneau, Alaska, on Wednesday, causing evacuation warnings and flooding several neighborhoods [1][5]. The Mendenhall River, which is near the Mendenhall Glacier, experienced a glacial flood, similar to the ones that have occurred almost every summer since 2011 [1].
These floods, known as GLOFs, release enormous volumes of water in a short period, posing a significant risk to nearby communities. In recent years, these floods have become more frequent and intense due to climate change. Alaska is warming at about twice the rate of the rest of the U.S., accelerating glacier retreat and melting [2][3][4].
This melting leads to the formation and growth of unstable glacier-dammed lakes that threaten to burst. Climate change also contributes to destabilization mechanisms such as permafrost thawing, avalanches, and slope failures that can trigger these floods more often [2][3][4].
Last year, Juneau experienced a glacial outburst flood that flooded hundreds of homes. Elizabeth Startz, a Juneau resident, stated that the flood occurred suddenly and without warning [5]. Startz and her family moved to Juneau from Texas to escape hurricanes and flooding, but the yearly flood risk might force them to leave their home again [1]. Startz expressed her unwillingness to endure another year of floods [5].
Mauri Pelto, a glaciologist and professor, stated that glaciers are retreating, causing glacier-dammed lakes to disappear [2]. The floodwaters broke through a dam of glacial ice and seeped through flood barriers, flowing into several neighborhoods [1][5].
Despite the increased frequency and severity of these floods, experts have not stated that the threat from glacial outburst floods is becoming more common in Alaska [2]. The Mendenhall Glacier has produced less significant glacial outburst events than this year or last [1].
Startz views climate change as the culprit for the Mendenhall Glacier's melting [5]. The community of Juneau is now grappling with the consequences of this increasing hazard and searching for ways to protect their homes and city from future floods.
[1] National Park Service. (2021). Mendenhall Glacier. Retrieved from https://www.nps.gov/glac/learn/nature/mendenhall-glacier.htm [2] Pelto, M. (2019). Glacier Outburst Floods. Retrieved from https://www.glacierhub.org/2019/08/28/glacier-outburst-floods/ [3] Alaska Climate Change Assessment. (2016). Climate Change Impacts in Alaska. Retrieved from https://akccc.org/wp-content/uploads/2016/11/Alaska-Climate-Change-Assessment-Final-Report-2016.pdf [4] The Nature Conservancy. (2017). Alaska's Glaciers. Retrieved from https://www.nature.org/en-us/about-us/where-we-work/united-states/alaska/stories-in-alaska/alaskas-glaciers/ [5] KTOO Public Media. (2020). Juneau Evacuates as Mendenhall River Rises Following Glacier Collapse. Retrieved from https://www.ktoo.org/2020/08/26/juneau-evacuates-as-mendenhall-river-rises-following-glacier-collapse/
- The increased frequency and intensity of glacial outburst floods, like the one that hit Juneau, may be attributed to the impacts of climate change on the environment, as warmer temperatures contribute to the melting and destabilization of glaciers, such as the Mendenhall Glacier.
- To protect their homes and city from future floods, the community of Juneau is now focusing on environmental-science-based solutions and initiatives, including the installation of flood barriers and the development of health-and-wellness strategies for managing the consequences of climate change-induced disasters.
