EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The effects of (supra-, en-, and sub-glacial) sediment on mountain glaciers

Leif S. Anderson1,2,3, Ian Delaney2, Dirk Scherler3,4, and Frédéric Herman2
Leif S. Anderson et al.
  • 1Department of Geology and Geophysics, University of Utah, Salt Lake City, United States of America (
  • 2Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
  • 3German Centre for Geoscience Research, Potsdam, Germany
  • 4Department of Earth Sciences, Freie Universität, Berlin, Germany

In mountainous environments, steep hillslopes tend to erode rapidly. These hillslopes, where present above glaciers, trundle rocks onto glacier surfaces below them. The loose rocks (debris) are subsequently transported along with glacial ice as it moves down valley. Debris can be so abundant that it produces continuous blankets across glaciers. Where debris cover is extensive it reduces ice melt and lowers the surface slope of glaciers. This feeds back to reduce basal sliding, thus impacting bedrock erosion. The erosion of bedrock produces loose sediment that is transported down valley along with the ice and by subglacial water flow.

Here, using a coupled numerical model, we tie three realms of sediment transport (supraglacial, englacial, and subglacial) with feedbacks between ice dynamics and surface melt. The model runs in 2D (x, z) using the shallow-ice approximation and a simple formulation for melt under debris. Our simulations use glaciological parameters meant to loosely represent glaciers in the Khumbu region of Nepal. We present numerical experiments to reveal the first order effects of debris cover on erosion and landscape evolution.

How to cite: Anderson, L. S., Delaney, I., Scherler, D., and Herman, F.: The effects of (supra-, en-, and sub-glacial) sediment on mountain glaciers, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10920,, 2022.