University of Utah geologists mapped the Timpanogos Rock Glacier using 232 precise gravity readings in fall 2024, discovering 1.55 million cubic meters of hidden ice beneath Mount Timpanogos. The reservoir contains enough water to fill about 600 Olympic swimming pools, offering new insight into mountain hydrology and climate resilience.
Uncovering the Invisible Ice Beneath Mount Timpanogos
From a distance, the Timpanogos Rock Glacier resembles a standard sprawling field of loose rock high in the Wasatch Range. Hikers scaling the trail from the trailhead to Emerald Lake walk across rubble, unaware of the massive frozen reservoir resting directly below their feet. Recent fieldwork reveals that the formation is remarkably ice-rich, consisting of 83% ice and 17% loose rock, with the frozen body buried up to 150 feet deep at its thickest point.
To see beneath the rocky surface without disturbing the terrain, researchers deployed a sophisticated gravimeter across the landscape. The project was led during the fall of 2024 by former Department of Geology & Geophysics graduate student Bronson Cvijanovich alongside geophysics professor Michael Thorne and glaciology professor Leif Anderson. Cvijanovich made six trips up the mountain, carrying sensitive equipment across a five-mile trail with a 3,500-foot elevation gain.
How 232 Gravity Readings Created a 3D Glacier Map
The research team collected measurements at 232 distinct locations spaced about 25 meters apart in a precise grid atop the glacier. This approach relies on the density differences between solid mountain rock and lighter buried ice. Denser material exerts a stronger gravitational pull, whereas areas with thicker ice register a slightly weaker pull.
If you go from measuring gravitational acceleration over rock — like over the rock that makes up Mount Timpanogos, it has greater mass, greater density. But then if I walk over an area that has thicker ice, that ice has less density than the rock,
explained glaciologist Leif Anderson, detailing how the modeling process works to determine subterranean ice thickness.
After gathering the field numbers, the team applied mathematical corrections to account for terrain variations, latitude, elevation, and the gravitational pull of the sun and the moon. They then processed the corrected data through months of Bayesian statistical modeling. The resulting three-dimensional computer reconstruction offered an unprecedented look inside the geological structure, which Cvijanovich noted holds a volume roughly equivalent to the largest pyramid at Giza in Egypt.
The Formation Mechanics and Wider Environmental Stakes
Unlike exposed glaciers shaped entirely by direct snowfall accumulation, rock glaciers grow through a combination of snowfall and rockfalls. Steep mountain slopes shed debris that covers and insulates persistent patches of snow in high cirques. That protective stone blanket prevents the snow from melting away completely during warm summer months, steadily adding mass over generations.
As timesofindia.indiatimes.com point out, the heavy rock cover shields the ice from heat and sun. Consequently, rock glacier ice melts much slower than exposed ice, sustaining stream flows and groundwater levels late into the summer season after seasonal snowpacks have vanished.
Beyond Utah, where state surveys have identified 836 rock glaciers, the findings carry global implications.
Climate Shifts and Monitoring Mountain Hazards
