EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Inferring rock glacier genesis and dynamics from age-layer modelling and borehole age-profile

Gwendolyn J.-M. C. Leysinger Vieli1, Andreas Vieli1, and Alessandro Cicoira1,2
Gwendolyn J.-M. C. Leysinger Vieli et al.
  • 1Department of Geography, University of Zurich, Zürich, Switzerland (
  • 2Snow and Avalanche Simulation Laboratory (SLAB), Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland

The genesis of rock glaciers differs fundamentally from ‘normal’ glaciers and results in much older landforms that are often reaching ages of several millennia. Recent datings of rock glacier material from boreholes indicate early Holocene ages for rock glaciers and allow the derivation of age-depth profiles at the borehole location. We use here a 2-dimensional numerical modelling approach that calculates age-layers (isochrones) within the rock glacier body and that considers the accretion, melt and flow-advection of rock glacier material. We apply this model to the case of Lazaun rock glacier (Southern Ötztal Alps) for which a well dated profile from a borehole exists, with ages at the bottom older than 9000 years (Krainer et al. 2015). With our modelling we are able to reproduce the observed age-depth profiles well and are able to infer a long-term accumulation rate that is around 1 cm/yr which is an order of magnitude higher than a previous estimate that does not account for deformation. The modelling is consistent with the classic rock glacier genesis of material accretion in the upstream talus slope and confirms the dominance of deformation in the shear-zone at the bottom layer of the rock glacier.
We conclude that combining age-layer modelling with dated depth-profiles of rock glaciers allows for important new insights into our understanding of rock glacier evolution and dynamics.

Krainer, K., Bressan, D., Dietre, B., Haas, J., Hajdas, I., Lang, K. & Tonidandel, D. (2015). A 10,300-year-old permafrost core from the active rock glacier Lazaun, southern Oetztal Alps (South Tyrol, Northern Italy). Quaternary Research, 83 , 324-335. 


How to cite: Leysinger Vieli, G. J.-M. C., Vieli, A., and Cicoira, A.: Inferring rock glacier genesis and dynamics from age-layer modelling and borehole age-profile, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11682,, 2021.

This abstract will not be presented.