Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-58874
Hasler, A; Gruber, S; Font, M; Dubois, A (2011). Advective heat transport in frozen rock clefts: Conceptual model, laboratory experiments and numerical simulation. Permafrost and Periglacial Processes, 22(4):378-389.
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Advective heat transported by water percolating into discontinuities in frozen ground can rapidly increase temperatures at depth because it provides a thermal shortcut between the atmosphere and the subsurface. Here, we develop a conceptual model that incorporates the main heat-exchange processes in a rock cleft. Laboratory experiments and numerical simulations based on the model indicate that latent heat release due to initial ice aggradation can rapidly warm cold bedrock and precondition it for later thermal erosion of cleft ice by advected sensible heat. The timing and duration of water percolation both affect the ice-level change if initial aggradation and subsequent erosion are of the same order of magnitude. The surplus advected heat is absorbed by cleft ice loss and runoff from the cleft so that this energy is not directly detectable in ground temperature records. Our findings suggest that thawing-related rockfall is possible even in cold permafrost if meltwater production and flow characteristics change significantly. Advective warming could rapidly affect failure planes beneath large rock masses and failure events could therefore differ greatly from common magnitude reaction-time relations.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Geography|
|DDC:||910 Geography & travel|
|Date:||13 December 2011|
|Deposited On:||05 Mar 2012 10:31|
|Last Modified:||02 Jan 2013 09:40|
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