EGU2020-8432
https://doi.org/10.5194/egusphere-egu2020-8432
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Quantifying post-glacial erosion at the Gorner glacier, Switzerland, using OSL and 10Be surface exposure dating.

Joanne Elkadi1, Benjamin Lehmann1,3, Georgina King1, Olivia Steinemann2, Susan Ivy-Ochs2, Marcus Christl2, and Frédéric Herman1
Joanne Elkadi et al.
  • 1Institute of Earth Surface Dynamics, University of Lausanne, 1012 Lausanne, Switzerland (joanne.elkadi@unil.ch)
  • 2Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland
  • 3Centro de Estudios Avanzados en Zonas Áridas (CEAZA), ULS—Campus Andrés Bello, Raúl Britán 1305, La Serena, Chile

Quaternary erosion through glacial and post-glacial processes has left an imprint on Alpine topography. There are few methods capable of resolving these processes on Late glacial to Holocene timescales. The aim of this study is to contribute towards a more detailed understanding of post-glacial erosion across the Central and Western Alps by better constraining the post-glacial erosion history of the Gorner glacier in Zermatt, Switzerland. This is done using a new approach that combines Optically Stimulated Luminescence (OSL) and 10Be cosmogenic nuclide surface exposure dating to invert for post-glacial erosion rates (Lehmann et al., 2019). Both dating methods are influenced by surface erosion but operate on different spatial scales- OSL signals form within the first 1-5 mm of a rock surface (Sohbati et al., 2011) whereas the 10Be signal accumulates within approximately the first 3 m (Lal, 1991). Six bedrock samples, exposed progressively since the Last Glacial Maximum, were collected along a vertical transect spanning an elevation of 641 m. Preliminary results show inheritance in the bottom three samples suggesting multiple advances and retreat. Further results for the post-glacial erosion rates down the transect, and comparison to other glaciers in the Western Alps, will be presented.

References:

Lal, D., 1991. Cosmic ray labelling of erosion surfaces: in situ nuclide production rates and erosion models. Earth and Planetary Science Letters, 104, 424-439.

Lehmann, B et al., 2019. Evaluating post-glacial bedrock erosion and surface exposure duration by coupling in situ optically stimulated luminescence and 10Be dating. Earth Surface Dynamics, 7.

Sohbati, R. et al., 2011. Investigating the resetting of OSL signals in rock surfaces. Geochronometria, 38(3), 249-258.

How to cite: Elkadi, J., Lehmann, B., King, G., Steinemann, O., Ivy-Ochs, S., Christl, M., and Herman, F.: Quantifying post-glacial erosion at the Gorner glacier, Switzerland, using OSL and 10Be surface exposure dating. , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8432, https://doi.org/10.5194/egusphere-egu2020-8432, 2020

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displays version 2 – uploaded on 06 May 2020, no comments
Added additional information on erosion function and extra results.
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