Resolving the influence of temperature forcing through heat conduction on rockglacier dynamics: a numerical modelling approach
In recent years, observations have highlighted seasonal and inter-annual variability in rockglacier flow. Temperature forcing, through heat conduction, has been proposed as one of the key processes to explain these variations in kinematics. However, this mechanism has not yet been quantitatively ass...
| Main Authors: | , , , , |
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| Format: | Report |
| Language: | English |
| Published: |
Copernicus
2018
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| Subjects: | |
| Online Access: | https://hdl.handle.net/20.500.11850/304692 https://doi.org/10.3929/ethz-b-000304692 |
| Summary: | In recent years, observations have highlighted seasonal and inter-annual variability in rockglacier flow. Temperature forcing, through heat conduction, has been proposed as one of the key processes to explain these variations in kinematics. However, this mechanism has not yet been quantitatively assessed against real-world data. We present a 1-D numerical modelling approach that couples heat conduction to an empirically derived creep model for ice-rich frozen soils. We use this model to investigate the effect of thermal heat conduction on seasonal and inter-annual variability in rockglacier flow. We compare the model results with borehole temperature data and surface velocity measurements from the PERMOS and PermaSense monitoring network in the Swiss Alps. We further conduct a model sensitivity analysis in order to resolve the importance of the different model parameters. Using the prescribed empirically derived rheology and observed near-surface temperatures, we are able to model the right order of magnitude of creep flow. However, both inter-annual and seasonal variability are underestimated by an order of magnitude, implying that heat conduction alone can not explain the observed variations. Therefore, non-conductive processes, likely linked to water availability, dominate the short-term velocity signal. ISSN:1994-0432 ISSN:1994-0440 |
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