Work

The Internal Ice Content of Timpanogos Rock Glacier, Utah, USA From 3‐D Bayesian Inversion of Gravity Data

Year: 2026

Type: article

Abstract: Despite the prevalence of rock glaciers in mountain environments, their ice volumes are poorly constrained. Rock glaciers persist in settings unable to support glaciers. They act as climate resilient water stores and refugia for cold‐adapted species while also posing a hazard to alpine communities. Imaging the entire internal structure of rock glaciers and estimating their ice volumes is crucial for understanding how these impacts evolve in a warming climate. Ice volume is challenging to measure with methods typically used on glaciers, such as aerial gravity and ground penetrating radar, due to the relatively small size of rock glaciers as well as the presence of internal and overlying debris. In this paper, we use an alternative approach: the terrestrial gravity method. We model the internal structure of Timpanogos Rock Glacier, Utah, USA using a 3‐D Bayesian inversion from 232 gravity measurements. Our inversions indicate an ice volume of 1.55 × 10 6 m 3 with an average thickness of 18.8 m and an ice fraction of 83% within the ice core. Measured surface velocities are consistent with ice thicknesses produced by our gravity inversions. Using our model results and measurements from geophysical studies of 10 other rock glaciers, we synthesize a new, linear area‐volume scaling relationship for rock glaciers. Using this relationship, we estimate a cumulative water volume equivalent of 48.03 Gt for the world's intact rock glaciers, 11.92 Gt for the western US, 0.99 Gt for the State of Utah, and 0.08 Gt for the Wasatch Mountain Range.

Source: Journal of Geophysical Research Earth Surface

DOI: 10.1029/2026jf009214