Buried rock glaciers could hold a billion tons of water in Utah

Rock piles scattered across Utah’s high mountain valleys may conceal vast stores of frozen water. University of Utah researchers estimate that the state’s 836 known rock glaciers could hold about 1 gigaton of water—roughly 266 billion gallons, or 815,000 acre-feet. Rock glaciers differ from conventional glaciers because their ice is covered by a thick layer of loose rock. Their surfaces can resemble ordinary piles of boulders, making the buried ice difficult to measure. The researchers focused on the Timpanogos Rock Glacier beneath Mount Timpanogos, near Salt Lake City and Provo, to develop a way to assess what lies below. During six field trips in fall 2024, geologist Bronson Cvijanovich recorded gravity measurements at 232 locations across the formation. The survey used a gravimeter to detect differences between the density of the surrounding rock and the lower-density ice beneath it. The measurements were adjusted for factors including terrain, elevation, latitude, and the gravitational effects of the sun and moon. The team then used a new Bayesian statistical method to create a three-dimensional image of the glacier’s internal ice. According to the University of Utah researchers, the Timpanogos formation contains about 1.5 million cubic meters of frozen water—enough to fill 600 Olympic-size swimming pools. They calculated that it is approximately 83% ice and 17% loose rock, with some buried ice reaching depths of about 120 feet. A separate study examined how the formation developed. The researchers’ model indicates that rockfalls gradually bury persistent snow in steep mountain cirques. Their findings suggest Utah’s rock glaciers formed during the thousands of years after Ice Age glaciers disappeared, rather than surviving unchanged from the Ice Age itself. Using the relationship between the surface area and buried ice volume at Timpanogos, the researchers estimated the water content of rock glaciers elsewhere. They calculated that roughly 50,000 known rock glaciers worldwide may contain 48 gigatons of water. The Utah estimate remains a calculation based on the Mount Timpanogos measurements and satellite-based identification of other formations.