A Peek Inside the Wheeler Cirque Glacier: Great Basin's Shrinking Ice

First published in The Midden, the Great Basin National Park newsletter, Vol. 21, No. 1, Summer 2021. By Gretchen Baker, ecologist.

Inside the Wheeler Cirque Glacier's crevasse. NPS photo by Gretchen Baker.

Then and now

Park ecologist Gretchen Baker had walked on glaciers in Alaska, on Mount Rainier, in New Zealand and in Argentina, but had never had a good look at Great Basin's own Wheeler Cirque Glacier.

In spring 2020 she heard from glacier enthusiasts working to raise awareness of retreating glaciers. They visited in September 2020 — a good month to see the ice — and she took them along to re-photograph the glacier from about where it had been photographed in 1958.

Lining up the old view showed how much it had shrunk:

• the dark line on the rock was far higher than today's ice, with much more rock now showing;
• people in 1958 were walking on a gentle slope of ice where, in 2020, the slope is steep;
• the team estimated the ice surface was about 40–60 feet lower in 2020 than in 1958.

Into the crevasse

With crampons and an ice axe, she climbed to the glacier's crevasse and measured it with a DistoX, a laser used in cave surveying: about 20 feet at its deepest. The back wall was rock; the front was ice, some of it melting.

What the glacier once was

• In the last Ice Age, the glacier flowed down the Lehman Creek drainage about as far as Mather Overlook.
• In an earlier Ice Age it reached even farther, stopping just short of Upper Lehman Campground.
• Moraines, cirques and other features still record those glaciers.

Why it matters

• Water: glacial ice — both exposed and inside the rock glacier — feeds water in late summer, when many other sources have dried up.
• Wildlife: the cold ice supports a flock of gray-crowned and black rosy-finches, which hop from spot to spot eating insects that fall onto the snow and ice.
• Its future: a tiny alpine glacier still sits above the rock glacier, but with the park warming rapidly, it is likely to disappear soon.

More from this issue of The Midden: the Nevada bat plan · changes in the park.

Sources

Based on "A Peek Inside the Wheeler Cirque Glacier," by Gretchen Baker, The Midden — Great Basin National Park, Vol. 21, No. 1, Summer 2021, National Park Service; a work of the United States government in the public domain.