Sponsor
This work was partly funded by U.S. Department of Agriculture, U.S. Forest Service (23-CS-11132400-355) and supported by Portland State University.
Published In
Arctic, Antarctic, and Alpine Research
Document Type
Article
Publication Date
2025
Subjects
Rock glaciers -- United States -- West, Rock glaciers -- Mapping, Remote sensing -- Geological applications
Abstract
Rock glaciers are relatively common in conterminous United States west of the 100° meridian, yet their distribution and number are not well known. Using aerial and satellite imagery, we inventoried the population of rock glaciers, yielding 2,257 rock glaciers totaling 234.28 km2 with an area of uncertainty of 7 percent. Of these, 1,561 (155.44 km2) are considered intact (moving) and 696 (76.84 km2) relict. Based on published estimates of ice content, total water-equivalent volume is roughly 2.52 km3. Rock glacier elevations increase from the northwest (Washington) to the southeast (Colorado), following a spatial trend of decreasing winter precipitation and increasing summer air temperature. Compared to alpine glaciers, rock glaciers are found in warmer, drier environments where winter precipitation < 1,200 mm, and relict rock glaciers inhabit warmer and drier conditions than intact rock glaciers. Locally, alpine glaciers exist at higher, colder, and wetter elevations than rock glaciers, and intact rock glaciers are found at higher elevations that relict ones. We also noted 7,850 “features of interest” that appeared to be nonflowing ice-rich landforms, many of which are similar in form to protalus ramparts and found in a climate common to relict rock glaciers.
Rights
© 2025 The Author(s). Published with license by Taylor & Francis Group, LLC.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
DOI
10.1080/15230430.2025.2546699
Persistent Identifier
https://archives.pdx.edu/ds/psu/44267
Citation Details
Allison Trcka, Andrew G. Fountain & Bryce Glenn (2025) The geography of rock glaciers in the American West, Arctic, Antarctic, and Alpine Research, 57:1, 2546699,
Description
The data that supports this article is available in PDXScholar.
https://doi.org/10.15760/geology-data.08