Abstract
Abstract
We assess the composition and geometry of four individual rock glaciers in Alaska, Wyoming and Colorado by measuring their radio wave speed and applying these results to ground-penetrating radar depth corrections and dielectric mixing models. Our method includes a correction for subsurface reflector dip angle, which we show can lead to an incorrect determination of wave speeds using common midpoint configurations. By observing the radar properties of the rock glaciers and their supraglacial debris, we find that some of the sites exhibit nearly pure ice cores, and all of the sites indicate volumetric ice fractions >50%. These results have implications for terrestrial glaciology and hydrology because the present ice volume is connected to past ice accumulation and subsurface ice preservation, which may affect the future availability of alpine water resources. An understanding of the processes that govern rock glacier evolution over a wide range of latitudes and elevations will also contribute to the exploration of planetary surfaces such as Mars, which hosts a significant population of debris-covered glaciers. Our subsurface composition and geometry estimates will inform simulations of rock glacier formation and evolution to test hypothesized ice origin mechanisms along with the preservation of climate signals.
Funder
National Aeronautics and Space Administration
Publisher
Cambridge University Press (CUP)
Reference45 articles.
1. Probing supraglacial debris on Mars 1: sources, thickness, and stratigraphy;Baker;Icarus,2019
2. Geophysical imaging of alpine rock glaciers;Maurer;Journal of Glaciology,2007
3. Petersen, EI and 7 others (2019b) The transition from Alpine Glacier to Rock Glacier at Sulphur Creek, Wyoming. Abstract C41E–1506, 2019 Fall Meeting: American Geophysical Union.
4. Electrical properties of rocks and their significance for lunar radar observations;Campbell;Journal of Geophysical Research,1969
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献