University of Utah Geologists Find Massive Water Store in Timpanogos Rock Glacier

When most people picture a glacier, they envision towering walls of exposed blue ice sliding down a mountain valley. But across Utah’s high alpine ranges, a far more deceptive kind of glacier hides in plain sight. These formations look like nothing more than sprawling fields of loose rock and rubble, masking massive frozen reservoirs underneath their stony armor. University of Utah geologists took a detailed look inside one of the state’s largest examples, the Timpanogos Rock Glacier situated beneath the rugged summit of Mount Timpanogos.

The resulting research reveals a staggering volume of hidden water. By employing sensitive gravitational measurements and advanced 3D imaging, the scientific team established that the Timpanogos formation contains about 1.5 million cubic meters of frozen water—enough to fill roughly 600 Olympic-sized swimming pools. That volume roughly equals the size of the largest pyramid at Giza in Egypt.

Measuring Mount Timpanogos With Gravimeters

Peering beneath a thick carapace of stone requires tools more commonly associated with geophysics than traditional mountaineering. During the fall of 2024, former graduate student Bronson Cvijanovich led a series of field expeditions above Emerald Lake, carrying state-of-the-art gravimeters across the terrain. Across six separate trips, the team collected precise gravity measurements at 232 locations arranged in a tight grid, spaced roughly 25 meters or 80 feet apart.

“Timpanogos Rock Glacier is surprisingly ice rich. It is 83% ice and 17% loose rock,” said Cvijanovich, lead author of one of the two studies overseen by geophysics professor Michael Thorne and glaciology professor Leif Anderson.

Bronson Cvijanovich, former graduate student in the Department of Geology & Geophysics

Gravimeters detect subtle differences in density, allowing researchers to distinguish the denser surrounding rock of the mountain from the much lighter buried ice. The team created a virtual map of the interior showing the glacier reaches up to 150 feet or 46 meters deep at its thickest point. Accounting for variables like the positions of the sun and moon, latitude, and elevation, the researchers spent months computing Bayesian statistical models to construct the final 3D imagery.

Atlantic Ocean’s Heat Valve Weakening

How Alpine Rockfalls Built Utah’s Ice Stores

Unlike the remnant ice fields left behind by ancient Ice Age glaciers, these rock glaciers formed during the millennia after those massive ice sheets disappeared. Two new studies examine how the glacier formed and reveal how much ice is buried inside it. An accompanying study examined the origin of the rock glaciers and suggests that they are water stores that formed over the thousands of years after the Ice Age glaciers melted away.

Glaciology professor Leif Anderson noted that hikers traversing these high-altitude rubble fields often remain completely unaware of the massive frozen foundations beneath their boots. 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, Anderson said.

“Rock glaciers flow downhill just like a glacier or river, but the important distinction here is that the thick carapace of loose rock actually protects and hides the ice, making these climate-resilient water storage sites that may still”

Bronson Cvijanovich, lead author of the study

Global Water Implications Across Arid Landscapes

Utah alone has 836 rock glaciers. There are more than 50,000 known rock glaciers around the world, more than 10,000 of which are located in the U.S. By correlating the surface area of Timpanogos with its measured ice volume, the research team scaled their calculations globally. The findings suggest that rock glaciers could collectively hold about 1 billion tons of ice, according to a new study published in the Journal of Geophysical Research: Earth Surfaces.

Based on the recent findings, the researchers estimate that Utah’s rock glaciers may hold a 1-gigaton, or 815,000 acre-feet, of water. Not every rock glacier remains active; some have melted out entirely over the centuries. Yet researchers confirmed that Mount Timpanogos continues to accrete ice today, offering a vital, climate-resilient hydrological buffer for warm and arid downstream regions. “This is not just ice that’s left from the time of Lake Bonneville and mammoths. We don’t yet know which rock glaciers are still adding ice today outside of a few dozen under active research. Some of these rubble fields hold ice today, but some have melted out,Anderson said. But Timpanogos rock glacier is still adding ice today!”