Utah is at the centre of an immense, invisible water reservoir buried beneath rocky mountain terrain across the western US. Findings from the underground ice study indicate that rock glaciers hold roughly 0.99 gigatonnes, or nearly one billion tons, of frozen water hidden beneath surface debris.
Scientists from the University of Utah collected hundreds of ultra-sensitive gravity measurements across the elevated Timpanogos Rock Glacier. Because ice is significantly less dense than surrounding bedrock, small variations in gravitational acceleration allowed researchers to construct precise three-dimensional models of internal ice deposits located beneath thick rubble blankets.
What Makes Utah’s Rock Glaciers So Resilient?
Unlike conventional surface glaciers exposed directly to rising atmospheric temperatures and solar radiation, Utah’s rock glaciers are covered by dense layers of rock and soil. This heavy outer rock blanket acts as a natural insulator, helping preserve underlying ice cores for thousands of years even as surrounding open ice fields shrink.
As summer snowpacks melt earlier in the season, thawing rock glaciers continuously release cool meltwater into local streams during late summer and early autumn periods. This sustained baseflow supports high-altitude mountain ecosystems, replenishes regional groundwater basins, and provides critical long-term water security for downstream communities facing prolonged dry spells.
Applying gravity-based 3D modeling techniques opens new avenues for mapping buried ice globally. Identifying these protected underground reserves ensures environmental scientists can better calculate regional freshwater availability as global climate patterns evolve.

