Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Constance I. MillarRobert D. WestfallDiane L. Delany
    Date: 2013
    Source: Quaternary International. 310:169-180
    Publication Series: Scientific Journal (JRNL)
    PDF: Download Publication  (2.56 MB)

    Description

    To explore thermal regimes and hydrologic capacity of rock glaciers and related periglacial talus landforms, mini-thermochrons were deployed in and around potentially ice-embedded features of the Sierra Nevada. Results from pilot studies at 13 rock glaciers and 7 taluses indicate that outlet springs from these landforms generally do not desiccate but persist year-round as ice (frozen) in winter and flowing water in the warm season. Temperatures of water (liquid and ice) in rock-glacier outlet springs had an annual mean of -0.2 °C and mean of 0.6 °C during the warm season with very low diurnal fluctuation. These and other attributes suggest the existence of internal ice and/or permafrost supplying the springs. Air temperatures of rock-glacier matrices (1 m below the surface) versus surface air corroborate the periglacial nature of internal environments: annual air temperatures of matrices were below freezing (mean, -0.8 °C). Compared to surface air, especially during the warm season, matrix air temperatures were significantly colder and fluctuated less. Talus landforms followed a similar pattern, although water- and matrix air temperatures were warmer, and contrasts with surface air were not as strong as for rock glaciers. For rock glaciers and talus slopes, matrix air temperatures showed resistance (buffering) to changes in external air temperatures. Unique geomorphic conditions of rock glaciers and periglacial taluses in the Sierra Nevada appear to maintain cool-buffered thermal regimes at least partly decoupled from external air. Springs support persistent wetlands and lakes at their snouts, retaining water in otherwise semi-arid high cirques, and contribute as hydrologic reserves and critical habitat for alpine biota. Daily and seasonal lags and buffering effects suggest that ice within these landforms might resist surface warming on the longer term, which could make these landforms increasingly important as regional climates change.

    Publication Notes

    • You may send email to psw_communications@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Millar, Constance I.; Westfall, Robert D.; Delany, Diane L. 2013. Thermal and hydrologic attributes of rock glaciers and periglacial talus landforms: Sierra Nevada, California, USA. Quaternary International. 310:169-180.

    Cited

    Google Scholar

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/44709