When we imagine a glacier, we tend to imagine a huge chunk of ice spread over a mountain valley or descending from a snow-covered peak. But not all glaciers look as expected. Some are hidden beneath a jumble of rocks, with the ice buried out of sight. These formations, known as rock glaciers, can hide vast reserves of ice beneath their rock surfaces. Now, scientists are taking a closer look at one of these ice reservoirs hidden beneath the Utah mountains and discovering that it may hold much more water than its modest appearance suggests. A team of geologists from the University of Utah took a closer look at one of the state’s largest rock glaciers located beneath Mount Timpanogos to examine how much ice it contained. By creating a 3D image of the hidden ice, the team discovered that the Timpanogos Rock glacier stores 1.5 million cubic meters of frozen water, enough to fill 600 Olympic-sized swimming pools. The findings suggest that rock glaciers could collectively contain around one billion tons of ice, according to a new study published in the Journal of Geophysical Research: Earth Surfaces. Buried Ice There are more than 50,000 known rock glaciers worldwide, more than 10,000 of which are in the US. Utah alone has 836 rock glaciers. These vast ice formations are hidden from view, buried under a dense layer of rock. “There is a lot of ice hidden in the mountains of Utah,” Leif Anderson, a professor of glaciology at the University of Utah and co-author of the study, said in a statement. “When we’re up in the mountains and we’re walking over loose rocks or debris, you don’t realize there could be 120 feet [37 meters] of buried ice beneath your feet.” To measure the amount of ice hiding inside the Timpanogos rock glacier, the team behind the study measured small differences in the gravitational pull of the rock and ice at 232 points on a grid at the top of the glacier. The measurements allowed the researchers to differentiate between the denser surrounding rock that makes up Mount Timpanogos and the much lighter buried ice. The team then created a virtual map of the interior of the Timpanogos rock glacier that measured 150 feet. [46 meters] deep in its thickest part. “The Timpanogos rock glacier is surprisingly rich in ice. It is 83% ice and 17% loose rock,” Bronson Cvijanovich, a former graduate student in the Department of Geology and Geophysics at the University of Utah and lead author of the study, said in a statement. Rock layers Based on recent findings, researchers estimate that Utah’s rock glaciers may contain 1 gigaton, or 815,000 acre-feet, of water. An accompanying study examined the origin of rock glaciers and suggests that they are reservoirs of water that formed over thousands of years after Ice Age glaciers melted. Despite the warmer climate, rock glaciers appear to be adding ice to this day. “This isn’t just ice left over from the time of Lake Bonneville and the mammoths. We still don’t know which rock glaciers still add ice today, other than a few dozen that are actively being investigated. Some of these debris fields contain ice today, but others have melted,” Anderson said. “But the Timpanogos Rock Glacier is still adding ice today!” Glaciers could then become a crucial source of water for places where there may be shortages. “Rock glaciers flow downhill like a glacier or a river, but the important distinction here is that the thick shell of loose rock actually protects and hides the ice, making them climate-resistant water storage sites that may still be adding frozen water,” Cvijanovich said. “From a water resources standpoint, it’s really important, especially in a hot, arid state like Utah.”
