Interaction of thermal and mechanical processes in steep permafrost rock walls: A conceptual approach

D. Draebing, M. Krautblatter, R. Dikau

Research output: Contribution to journalArticleAcademicpeer-review


Degradation of permafrost rock wall decreases stability and can initiate rock slope instability of all magnitudes. Rock instability is controlled by the balance of shear forces and shear resistances. The sensitivity of slope stability to warming results from a complex interplay of shear forces and resistances. Conductive, convective and advective heat transport processes act to warm, degrade and thaw permafrost in rock walls. On a seasonal scale, snow cover changes are a poorly understood key control of the timing and extent of thawing and permafrost degradation. We identified two potential critical time windows where shear forces might exceed shear resistances of the rock. In early summer combined hydrostatic and cryostatic pressure can cause a peak in shear force exceeding high frozen shear resistance and in autumn fast increasing shear forces can exceed slower increasing shear resistance. On a multiannual system scale, shear resistances change from predominantly rock-mechanically to ice-mechanically controlled. Progressive rock bridge failure results in an increase of sensitivity to warming. Climate change alters snow cover and duration and, hereby, thermal and mechanical processes in the rock wall. Amplified thawing of permafrost will result in higher rock slope instability and rock fall activity. We present a holistic conceptual approach connecting thermal and mechanical processes, validate parts of the model with geophysical and kinematic data and develop future scenarios to enhance understanding on system scale.
Original languageEnglish
Pages (from-to)226-235
Number of pages10
Publication statusPublished - 2014
Externally publishedYes


  • Rock stability
  • Rock permafrost
  • Snow cover
  • Thermal processes
  • Rock mechanical processes


Dive into the research topics of 'Interaction of thermal and mechanical processes in steep permafrost rock walls: A conceptual approach'. Together they form a unique fingerprint.

Cite this