Dr. Michael Loso / Photo by Heather Aronno
Eklutna glacier is melting, and whether you drink Anchorage water, use Anchorage electricity, or if you just like to go hiking or skiing around Eklutna lake, you should probably care. In a nutshell, this is the thesis of the latest Anchorage Science Pub presentation at the Tap Root. The speaker, Dr. Michael Loso, is an APU Associate Professor of Earth Sciences. Taking note of the venue, Loso began the lecture in a jovial tone:
“I’ve given presentations about this work at the Eklutna glacier a lot of times over the last few years and I’ve never been able to do this at one of my talks before, so I’m going to do it now. [Raises voice] Bartender, can I have a bourbon?”
Upon receiving his bourbon, it was quickly downed in one gulp to the applause of the crowd. For years, Loso’s research has been focused on glaciers and how they change over time. Leading multiple studies with his students on the Eklutna glacier and the lake it feeds into, Loso suggested succinctly why the those attending should care about its depletion: “Eklutna glacier feeds into Eklutna Lake, and Eklutna Lake is the source of most of the water for [Anchorage].”
Fed by the glacier and rainwater, Eklutna Lake’s only real drainage is into Anchorage’s water supply, and so it has been a reliable source of water for the city for many decades. According to Loso, 80 percent of Anchorage’s water supply and 15 percent of its electricity comes from Eklutna Lake. However, he warned that rising temperatures caused by climate change over those decades have shrunk the lake’s source by a considerable amount.
Pointing to a photo taken of the receding glacier’s ablation zone, Loso described how the shape of the standard entry point by most skiers had shrunk, making it more difficult to access by foot. He said the rock exposed by the shrinking ice is loose, and the surface is steeper than it was even a few years ago. The huts built by the Mountaineer Club of Alaska in the 1960s next to the glacier have stayed put, but the glacier hasn’t.
“You get finished after a day of skiing and the hut’s way up there [points his arm straight up], and it’s a sad, lonesome hike back to the hut.” While anecdotal, Loso said this is a way “to really see the effects of the glacier changing.”
Loso showed a series of charts and satellite imaging showing the gradual depletion of the Eklutna glacier, particularly in depth.
“We’re accustomed to thinking about glacier retreat in terms of the terminus melting backward. But really, when you’re talking about water, what really matters is the thinning of the glacier. That’s where all the volume is.”
Boiling down years of research, Loso explained that in the past 50-or-so years, the Eklutna glacier has lost about 973,000 acre feet of volume. This amounts to about 8 percent of Anchorage’s annual usage of the water from Eklutna Lake. Loso described this as “mining the glacier,” essentially taking water out of the glacier that hasn’t been replenished: “we’re not going to get that water forever.”
Loso kept his tone light and based his conclusions on data that he and his APU students have spent years gathering. While Anchorage isn’t near an emergency water shortage, Loso’s points are worth keeping in mind for conversations about resource usage and allocation in the years to come.
Watch this and previous presentations at the Anchorage Science Pub on the Alaska Commons’ Youtube channel.