Séminaire de David L. Egholm, Aarhus University, Denmark

Exploring subglacial erosion processes using cosmogenic nuclides and landscape evolution models

Séminaire de David L. Egholm, 2018

Abstract

Landscape evolution models (LEMs) have for some time been able to reproduce first-order glacial landforms, such as U-shaped valleys, cirques and ridges, from simple rules of glacial erosion. However, besides landforms, LEMs are typically not informed by other quantitative measurements, and the processes being modelled hence remain poorly constrained.
In order to improve this situation, we have designed LEMs that track the evolution on cosmogenic nuclides in the bedrock surface and in sediments being transported by ice. Although our results are still preliminary, we use this strategy to better understand the distribution of cosmogenic nuclides in glaciated or previously glaciated landscapes, and to gauge the uncertainties of exposure dating.
In this talk, I will first explain how the models work and then show examples from i) a glacially eroded bedrock plateau in Norway, and ii) a debris-covered glacier in the Indian Himalaya.