T265 Geologic Research in the Cascades: Understanding Glacier Change, Geologic Hazards, and Mountain Hydrology along an Active Margin in a Changing Climate (Posters)

Wednesday, 25 September 2024
8:00 AM - 5:30 PM
Hall D

HOW DOES GLACIAL DEBRIS COVER TEMPERATURE VARY WITH DEPTH AND OVER TIME?

Paper number: T265-4
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

  • Alan Salcedo Presenting Author
    California State University San Bernardino, San Bernardino, CA
  • Claire Todd
    California State University San Bernardino, San Bernardino, CA

Abstract

Nearly half of the world’s glaciers have rocky debris on their surface. Numerous studies have demonstrated that a thick layer of supraglacial debris reduces ice melt at the glacier surface, but a thin layer can accelerate surface melt by amplifying solar heating. To determine how debris cover thickness attenuates heat from solar radiation, we measured temperature at different depths within the debris cover on Emmons Glacier, Mount Rainier, WA. From July to September in 2018, 2019, and 2022, sensors attached to bamboo stakes recorded air temperature at ~ 1 m above the debris cover surface, and debris temperature at depths ranging from 1 – 40 cm below the surface. Sensors were installed at four sites each year, for a total of 12 measurement locations. Preliminary results show that temperatures within 15 cm of the debris cover surface often exceed air temperature, in some measurements by more than 20 degrees Celsius. We also observe evidence of heat retention within the debris cover in late summer when air temperatures were at or below ~ 10 degrees Celsius; in these instances, debris cover temperatures at all depths exceeded air temperature. Our data show that debris cover temperature varies at different locations on the glacier under the same atmospheric conditions; this finding suggests that debris cover characteristics and surface morphology may affect the insulating properties of supraglacial debris cover.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-405001

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