Scientists Find Huge Hidden Ice Reservoir Beneath Utah's Mountains

Rock glaciers look like fields of loose rock rather than ice, but can hide large amounts of frozen water underneath. They are common across Utah's Wasatch and Uinta ranges and the La Sal Mountains near Moab. University of Utah geologists studied the Timpanogos Rock Glacier beneath Mount Timpanogos near Salt Lake City and Provo in two new studies on its formation and ice.

Bronson Cvijanovich, a former University of Utah graduate student, led six field trips in fall 2024 to ice buried above Emerald Lake with a gravimeter -- which detects underground density differences -- at 232 points 25 meters apart. The team used Bayesian statistics, a method estimating hidden values from limited data, to build a 3D image of the interior. Geophysics professor Michael Thorne, who with glaciology professor Leif Anderson oversaw research, said the process took months of computation.

Results show Timpanogos Rock Glacier holds about 1.5 million cubic meters of frozen water -- enough to fill about 600 Olympic pools, about the same volume as the largest pyramid at Giza, Egypt, Cvijanovich said. The glacier is 83% ice and 17% rock. "There's a lot of ice that's hidden in Utah's mountains," Anderson said, noting hikers crossing rubble may not realize there could be 120 feet of ice buried beneath their feet.

A second study found Utah's rock glaciers form as debris eroding from mountainsides repeatedly buries persistent snow in high valleys, protecting it from melting. These glaciers are not Ice Age leftovers -- which peaked 21,000 to 18,000 years ago -- but developed over thousands of years afterward, researchers concluded.

Using the Timpanogos data, the team linked a rock glacier's surface area to its ice volume, then applied it to about 50,000 rock glaciers worldwide, estimating a combined 48 gigatons of water -- a gigaton equal to 1 billion metric tons, or a cubic kilometer, or 400,000 Olympic pools. Utah's 836 rock glaciers alone may hold about 1 gigaton, or about 815,000 acre-feet.