Geologists discovering 1.5 million cubic meters of frozen water beneath Mount Timpanogos reveal that Utah rock glaciers store massive, hidden water reserves. Two recent University of Utah studies utilized gravimeter measurements and Bayesian statistics to map the underground ice, offering critical insight into arid-state water resources and regional alpine evolution.
When we picture a glacier, we tend to imagine an enormous chunk of ice sprawling across a mountain valley or descending from a snow-covered peak. But not all alpine formations look the way we expect. Some are hidden beneath a jumble of rocks, their ice buried from view.
These formations, known as rock glaciers, conceal vast reservoirs of ice beneath their rocky surfaces. Now, scientists are taking a closer look at one of these hidden ice stores beneath Utah’s mountains—and finding that it contains far more water than its unassuming appearance suggests.
Mapping Hidden Ice Beneath Mount Timpanogos With Gravity
University of Utah geologists took a detailed look inside the Timpanogos Rock Glacier, one of the state’s largest examples located beneath the prominent summit of Mount Timpanogos near Salt Lake City and Provo. By detecting extremely small differences in the gravitational pull of rock and ice, researchers developed a new way to create a 3D image of the hidden ice within a large rock glacier.
The results show that the Timpanogos Rock Glacier contains about 1.5 million cubic meters of frozen water, enough to fill roughly 600 Olympic swimming pools. Bronson Cvijanovich noted that this volume is roughly the same as the largest pyramid at Giza in Egypt.
Timpanogos Rock Glacier is surprisingly ice rich.
Bronson Cvijanovich, lead author and former graduate student in the Department of Geology & Geophysics
During the fall of 2024, Cvijanovich led a series of field trips to the site above Emerald Lake, carrying sensitive equipment including a state-of-the-art gravimeter. Across six trips, the team collected gravity measurements at 232 locations arranged in a grid, with each point separated by 25 meters, or about 80 feet. Because gravimeters detect differences in density, the instrument allowed researchers to distinguish the denser surrounding rock from the much lighter buried ice.
The team then had to account for subtle changes caused by the positions of the sun and moon, as well as differences in terrain, latitude, and elevation. After making those corrections, the researchers developed a new method for reconstructing the glacier’s internal ice in three dimensions using Bayesian statistics.
“There’s a lot of ice that’s hidden in Utah’s mountains. When we are high in the mountains and walking across loose rocks or rubble, you don’t realize there could be 120 feet of ice buried beneath your feet.”
Leif Anderson, glaciology professor at the University of Utah and co-author of the study
Origins and Formation of Utah’s Rock Glaciers
An accompanying study examined the origin of these formations, indicating that they are not leftover features from the Ice Age, which reached its peak 21,000 to 18,000 years ago. Instead, they are reservoirs of frozen water that developed during the thousands of years after the major Ice Age glaciers disappeared.
Rock glaciers commonly develop beneath steep mountain valleys or cirques where falling debris regularly collects. In the Wasatch Mountains, that falling material plays a key role in protecting snow from melting.
Anderson noted that the mountains themselves are eroding and burying the snow, which is why the rock glaciers exist. The mathematical model developed by the researchers suggests that rockfalls repeatedly cover persistent snow in the upper sections, adding mass and helping preserve the snow beneath layers of debris.
Crucially, some of these formations continue to grow today. While some rubble fields have melted out, Anderson confirmed that the Timpanogos Rock Glacier is still adding ice.
Global Implications for Climate-Resilient Water Supplies
Utah alone has 836 rock glaciers identified through satellite imagery. By establishing a relationship between a rock glacier’s surface area and the volume of ice stored underneath it at Timpanogos, the researchers applied that relationship more broadly. Their calculations suggest that the roughly 50,000 known rock glaciers around the world could collectively contain about 48 gigatons of water.
On a state level, the findings published in the Journal of Geophysical Research: Earth Surfaces estimate that Utah’s rock glaciers may hold 1 gigaton, or 815,000 acre-feet, of water.
Because the thick carapace of loose rock protects and hides the ice, these formations act as climate-resilient water storage sites. From a water resource standpoint, this subterranean storage is vital for managing supplies in a warm and arid state like Utah.