Researchers at the University of Utah have revealed that the state’s mountains may conceal a staggering one billion tons of underground ice within 836 documented rock glaciers. Using a sensitive gravimeter and new three-dimensional modeling techniques, the study maps hidden water stores on Mount Timpanogos and redefines how geologists assess mountain glaciers.
Weighing Mountain Ice With a Gravimeter
When hikers traverse high-elevation mountain terrain across Utah, they tread over loose rock and rubble without realizing what sits directly below their boots. A team of geologists at the University of Utah found that these seemingly ordinary boulder fields often mask massive ice deposits. Timpanogos Rock Glacier, situated near Emerald Lake above Salt Lake City and Provo, served as the primary test subject for this novel investigation.
Conventional glaciology relies heavily on ground-penetrating radar to image internal glacier structures. That technology fails when applied to rock glaciers because the debris mixed directly into the frozen mass scatters radio waves, destroying image clarity. To bypass this barrier, Bronson Cvijanovich and fellow researchers carried heavy field equipment up a steep, five-mile trail with an elevation gain of 3,500 feet.
In the fall of 2024, the team hauled roughly 300 pounds of gear into the field, working from sunrise to sundown. Amid high-elevation winds that required building temporary wind barriers around their instruments, Cvijanovich recorded gravity readings at 232 distinct points spaced across a tight grid. They deployed a CG6 Relative Gravimeter to measure microscopic changes in gravitational acceleration caused by subsurface density differences.
By tracking how gravity weakened slightly over areas holding thicker subsurface ice, the researchers developed a new method to image the ice in 3D. After correcting their gravity observations for the positions of the sun and moon, terrain layout, latitude, and elevation, they applied Bayesian statistics and computational modeling to reconstruct the internal architecture of the formation.
Inside the Mount Timpanogos Ice Repository
The resulting models reveal a subterranean structure far richer in frozen water than previously understood. The Mount Timpanogos formation consists of approximately 83 percent ice and 17 percent rocky debris by volume, according to the findings published in the Journal of Geophysical Research: Earth Surface. At its thickest point, the buried ice body reaches roughly 150 feet deep, maintaining an average thickness of 18.8 meters across the rock glacier.
Quantifying that volume yields striking comparisons. The Timpanogos Rock Glacier stores roughly 1.5 million cubic meters of ice, which equates to about 1.4 million metric tons (1.5 million US tons) of frozen water. That mass equals the volume of the Great Pyramid of Giza in Egypt, or enough water to fill 600 Olympic swimming pools. Glaciologist Leif Anderson noted the sheer scale of what remains hidden beneath mountain footpaths.
A separate study led by the same team addresses the physical enigma of how these rock glaciers grow in the first place. The researchers formulated a new mathematical model showing how steep-walled mountain valleys shed debris that covers and insulates persistent snowpack over successive seasons. Years characterized by high snowfall totals, lower summer temperatures, and frequent rockfalls drive the accumulation of mass. Once these debris-covered ice masses attain sufficient thickness, gravity pulls them downslope at a rate of roughly half a foot to a foot per year.
Scaling the Findings Across Utah and Beyond
With data secured from Mount Timpanogos, the research team expanded their calculations to estimate ice volumes across the wider American West. By correlating surface area measurements with the internal composition data gathered by the gravimeter, they produced statewide and global projections.
Utah’s 836 documented rock glaciers—over half of which hide within the Uinta Mountain Range, with others scattered through the Wasatch Range and the La Sal Mountains near Moab—collectively store about 1 billion tons of ice. Expanding those formulas regionally points to nearly 12 billion tons across the western United States, and roughly 48 billion tons stored globally inside rock glaciers.
These numbers carry practical implications for regional hydrology and hazard management. Because a heavy layer of rocks shields the underlying ice from direct solar radiation and surface heat, rock glaciers exhibit greater resilience to climate change than conventional, exposed glaciers. However, warming periods can eventually destabilize them, posing potential threats to downstream infrastructure.
Geophysicists intend to refine their gravimetry technique further and apply it to other geological settings beyond rock glaciers. As alpine environments continue to shift under rising global temperatures, the newly established 3D mapping framework provides researchers with a baseline to track vanishing water resources locked inside hidden mountain stores.
