Driving mechanisms of permafrost coastal erosion investigated by laboratory model experiments
Arctic permafrost coasts face rising wave heights, air, and water temperature due to climate warming. This leads to greater coastal erosion and a series of potential impacts on coastal infrastructure and ecosystems. The empirical link between the changing climate and erosion is known, yet the actual...
| Main Authors: | , , , |
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| Format: | Lecture |
| Language: | unknown |
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Zenodo
2023
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| Subjects: | |
| Online Access: | https://doi.org/10.52381/EUCOP6.abstracts.1 https://eucop2023.com/wp-content/uploads/2023/06/EUCOP2023-ABSTRACTS.pdf |
| Summary: | Arctic permafrost coasts face rising wave heights, air, and water temperature due to climate warming. This leads to greater coastal erosion and a series of potential impacts on coastal infrastructure and ecosystems. The empirical link between the changing climate and erosion is known, yet the actual mechanisms underpinning erosion are poorly understood. A physics-based quantification of these mechanisms is necessary for sound projections of global and local permafrost coastal erosion rates. Reduced scale laboratory model experiments are widely used in temperate regions for the investigation of coastal process, e.g., coastal dune erosion, where complexity is reduced by focusing attention on specific environmental drivers separately. So far, permafrost coastal erosion was not addressed by this method, yet it bears great potential to identify and quantify the processes underpinning coastal permafrost erosion. Here, we simulated permafrost coastal erosion with a modular 0.3 m-wide wave tank inside an adjustable temperature-controlled climate chamber. The permafrost itself was represented by a standardized frozen sediment block made of uniform fine grain sand saturated with water. Errors associated with potential model unconformities were reduced with the use of triplicated experiments and blank tests. We tested the set-up with four different wave conditions and water temperatures matching the range of observed conditions in the coastal Arctic. The resulting thaw depth was measured at the erosion surface, while crest retreat rates and volumetric erosion were calculated with point clouds from laser scanning. This work presents early results from the experiment and the lessons learnt from setting up a unique experimental framework to study permafrost coastal erosion in controlled laboratory conditions. Quantifying the driving processes will facilitate to incorporate permafrost coastal erosion in future earth system models and build prognostic capacities to aid local solutions to mitigate erosion of critical ... |
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