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(Article of periodic en Anglais - 2013)

Document title

Why permafrost rocks become unstable : a rock–ice-mechanical model in time and space

Authors(s) and Affiliation(s)

KRAUTBLATTER M. (1) ; FUNK D. (2) ; GÜNZEL F.K. (3) ;
(1) Technische Universität München, Munich, ALLEMAGNE
(2) Dept. of Geography, Univ., Bonn, ALLEMAGNE
(3) Univ., Brighton, ROYAUME-UNI

Abstract

Here, the AA. develop a mechanical model that relates the destabilization of thawing permafrost rock slopes to temperature-related effects on both, rock- and ice-mechanics; and laboratory testing of key assumptions is performed. The destabilization is commonly attributed to changes in ice-mechanical properties while bedrock friction and fracture propagation have not been considered yet. However, fracture toughness, compressive and tensile strength decrease by up to 50% and more when intact water-saturated rock thaws. Based on literature and experiments, the AA. develop a modified Mohr-Coulomb failure criterion for ice-filled rock fractures that incorporates fracturing of rock bridges, friction of rough fracture surfaces, ductile creep of ice and detachment mechanisms along rock-ice interfaces. Novel laboratory setups were developed to assess the temperature dependency of the friction of ice-free rock-rock interfaces and the shear detachment of rock-ice interfaces. The model explains why all magnitudes of rock–slope failures can be prepared and triggered by permafrost degradation and is capable of conditioning long para-glacial response times

Source

Article of periodic

published at : Earth surface processes and landforms / ISSN 0197-9337 / CODEN ESPLDB

Editor : Wiley, Chichester - ROYAUME-UNI (1981)

Millesime : 2013, vol. 38, no8 [pp. 876-887]

Bibliographic references : 2 p.

Collation : 9 fig.

Language

Anglais

INIST-CNRS, Cote INIST : 17355

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1002/esp.3374

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2014
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