Utah’s Rocky Slopes Conceal Nearly 1 Billion Tons of Water, Gravity Study Finds

Utah’s mountain slopes may look dry and covered only by loose rock, but nearly 1 billion tons of frozen water lie beneath some of them. Researchers estimate that the state’s rock glaciers contain about 0.99 gigatonnes of water equivalent.

The findings come from a study of the Timpanogos Rock Glacier beneath Mount Timpanogos. Unlike exposed glaciers, rock glaciers hide their ice beneath thick layers of stones and debris. The rocky cover insulates the ice from sunlight and warmth, allowing it to survive in mountain environments that may no longer support conventional glaciers.

Scientists used 232 gravity measurements to examine the formation without drilling through it. Because ice is less dense than bedrock, a large buried ice mass produces a small reduction in gravitational acceleration. The researchers used those variations in a three-dimensional Bayesian inversion to reconstruct the glacier’s hidden structure.

The study estimated the glacier’s ice volume at about 1.55 million cubic metres, with an average thickness of 18.8 metres. The researchers’ preferred model indicates that the entire formation is about 72% ice by volume, while its ice core is approximately 83% ice.

The researchers say rock glaciers are becoming more important as climate change reduces conventional glacier ice. They can store water and provide refuges for cold-adapted species, but their destabilisation can also create hazards for communities below. The research was published in the Journal of Geophysical Research: Earth Surface.