Paper contribution

Rock mass instabilities in periglacial environments induced by climate change

Frederic Pellet; Xiaoqin Lei

Proceedings
EUROCK 2026
Pages
1119-1124
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

Climate change, manifested by increasing air temperatures in high-altitude environments, is driving the degradation of mountain permafrost, resulting in a growing number of large-scale rock mass instabilities. This phenomenon is particularly evident in the French Alps, where high granite peaks are frequently affected by major rockfall and collapse events. Although these processes rarely cause human casualties, their economic and infrastructural consequences can be significant, especially in areas with dense tourism and transport infrastructure. The thawing of ice lenses within rock joints induces mechanical destabilization through the loss of interstitial ice cohesion and a redistribution of stresses onto rock bridges. When failure does not occur immediately, delayed rupture may arise through time-dependent deformation mechanisms (creep) and chemically driven weakening processes, such as stress corrosion cracking. In addition, repeated freeze–thaw cycles promote fatigue damage, accelerating the degradation of rock strength and facilitating fracture propagation. These cumulative effects, occasionally compounded by low-magnitude seismic activity, contribute to the progressive weakening and instability of alpine rock slopes. This paper presents a selection of case studies, notably the summit station of the Aiguille du Midi cable car in the Mont Blanc massif, where significant rock mass deformation associated with permafrost thaw may compromise the long-term structural integrity and operational viability of the installation, potentially leading to its closure within the coming decades.

Contributors

Authors

  1. Frederic Pellet Alparock Consulting, Annemasse, France ORCID 0000-0002-3950-8114
  2. Xiaoqin Lei Institute of Mountain Hazards and Environment, CAS, Chengdu, China

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References

  1. Atkinson, B. K. (1987). Fracture Mechanics of Rock. Academic Press.
  2. Cuffey, K. M., and Paterson, W. S. B. (2010). The Physics of Glaciers (4th ed.). Academic Press.
  3. Davies, M. C. R., Hamza, O., Lumsden B.W. and Harris, C. (2000). Laboratory measurement of the shear strength of ice-filled rock joints. Annals of Glaciology, 31:463-467
  4. Gatelier N. Pellet F.L. and Loret B. (2002) Mechanical damage of an anisotropic porous rock in cyclic triaxial tests, International Journal of Rock Mechanics and Mining Sciences, 39: 335-354,
  5. Gruber S. and Haeberli W. (2007). Permafrost in steep bedrock slopes and its temperature-related destabilization. Journal of Geophysical Research: Earth Surface, 112(F2).
  6. Jellinek, H.H.G. (1959). Adhesive Properties of Ice. Journal of Colloid Science, 14: 268 - 280.
  7. Magnin, F., Josnin, J.-Y., Ravanel, L., Pergaud, J., Pohl, B., and Deline, P. (2017). Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century, The Cryosphere, 11, 1813–1834,
  8. Ngo D.T. and Pellet F.L. (2018), Numerical modeling of thermally-induced fractures in a large rock salt mass, Journal of Rock Mechanics and Geotechnical Engineering, 10: 844-855.
  9. ParisP.,Erdogan F. (1963)A critical analysis of crack propagation laws. Journal of Basic Engineering.85(4): 528-533
  10. Schulson, E. M., and Duval, P. (2009). Creep and Fracture of Ice. Cambridge University Press.
  11. Torsello G. (2025) Failure of fractured rock masses in periglacial environments - Experimental investigations on freeze-thaw induced damage, PhD dissertation at Politecnico di Torino, Italy.
  12. Walder, J. S., and Hallet, B. (1985). A theoretical model of the fracture of rock during freezing. Geological Society of America Bulletin, 96(3), 336–346.