Quantification of post-glacier bedrock surface erosion in the European Alps using <sup>10</sup>Be and optically stimulated luminescence exposure dating
<p>The retreat of glaciers since the Last Glacial Maximum in the European Alps has left an imprint on topography through various erosional processes. However, few methods are currently capable of resolving these mechanisms on Late Glacial to Holocene timescales. Quantifying the relative contri...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-09-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://esurf.copernicus.org/articles/10/909/2022/esurf-10-909-2022.pdf |
| Summary: | <p>The retreat of glaciers since the Last Glacial Maximum in the European Alps has left an imprint on topography through various erosional processes. However, few methods are currently capable of resolving these mechanisms on Late Glacial to Holocene timescales. Quantifying the relative contributions of mountain erosion, during these different climate cycles, is useful for understanding long-term landscape evolution and the links between global climate and erosion. Here, we combine three optically stimulated luminescence (OSL) exposure dating signals with <span class="inline-formula"><sup>10</sup>Be</span> surface exposure dating to constrain the post-glacier erosion rates of bedrock samples adjacent to the Gorner Glacier in the European Alps. The results reveal erosion rates of the order of 10<span class="inline-formula"><sup>−2</sup></span> to 10<span class="inline-formula"><sup>−1</sup></span> <span class="inline-formula">mm a<sup>−1</sup></span>, in general agreement with other studies in the region, as well as a strong negative correlation between erosion rate and elevation, suggesting that frost crack weathering is perhaps not the dominant form of post-glacier weathering. Finally, a global compilation of both subglacial and periglacial erosion rates shows that periglacial erosion rates could be greater than previously thought. Yet subglacial erosion remains higher, implying that it continues to have the stronger influence on shaping landscapes. Therefore, with a changing climate, periglacial erosion rates are likely to remain transient. These insights could lead to important implications for landscape evolution models.</p> |
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| ISSN: | 2196-6311 2196-632X |