While there is no doubt regarding the highly erosive nature of glaciers and their ability to shape the Earth’s surface, establishing precise data-based parameters to measure this erosion in landscape evolution models has proved challenging.
According to University of Dundee Geoscientist Simon Cook, the empirical basis for the current model for measuring the rate of glacial erosion (as a function of glacier sliding velocity) is weak, and the assumption that climate controls erosion via sliding velocity also merits further empirical scrutiny.
Authored by Simon Cook and co-authored by Darrel Swift, Martin Kirkbride, Peter Knight, and Richard Waller, the paper ‘The empirical basis for modelling glacial erosion rates’ published on 6 February, 2020 by Nature Communications presents empirically sound data - based on a global compilation of 38 glaciers – that define how erosion rates, sliding velocities, and climate work together.
“Previous models of glacial erosion at the landscape-scale have been based on data from a single glacier (the Variegated Glacier in Alaska), which has a rather unusual behavior – it surges forward periodically," says Cook. "What we tried to do here was provide a more robust dataset based on a much wider range of glaciers and locations. We hope that this will improve the representativeness of future modelling efforts.”
The results from the study show that sliding has a positive correlation with erosion, and this correlation is now incorporated in erosion models. Additionally, the authors found that precipitation plays a more significant role in rapid erosion than previously thought, as rapid erosion occurs at temperate glaciers with high mean annual precipitation.
“Previous studies have demonstrated a link between temperature and erosion rate, but there are barely any studies of how precipitation might influence erosion. Together, temperature and precipitation seem to determine how much erosion a glacier will be able to do,” says Cook.
Citation
Cook, S.J., Swift, D.A., Kirkbride, M.P. et al. The empirical basis for modelling glacial erosion rates. Nat Commun 11, 759 (2020). https://doi.org/10.1038/s41467-020-14583-8
This is an open access article originally published on nature.com on 6 February, 2020 and distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Photo by Abdullah Shakoor
