Rock slope instability and erosion: toward improved process understanding

Abstract

Rock slopes in a range of environments are among the landscape elements most sensitive to climate change, the latter affecting rock mass properties, altering slope boundary conditions, and changing geosystem configurations. Major climate‐dependent influences promoting destabilization include stress redistribution with changing glacial ice extents, degradation of mountain permafrost, altered slope hydrology and weathering environments, loading and unloading due to deposition and erosion, and changes in the spectrum of magnitude and frequency of driving forces. In steep bedrock terrain, erosional processes control slope morphology by modulating rates of: (i) weathering in response to climate and pre‐disposition, (ii) rock slope retreat in response to magnitude and frequency of detachment, and (iii) channel incision or valley infilling in response to variable sediment supply. Modelling landscape evolution and anticipating natural hazards in these environments thus requires deeper insights into the processes driving rock slope instability and erosion. This special issue emphasizes new understanding of rock slope processes through a collection of manuscripts at the forefront of research in the field. Copyright © 2014 John Wiley & Sons, Ltd.

Multistage Rock‐Slope Failures Revealed in Lake Sediments in a Seismically Active Alpine Region (Lake Oeschinen, Switzerland)

“…The high recurrence rates and the multistage character of the rock‐slope failures in a proglacial environment also support the role of triggers like stress adaptation and altered rock mass strength due to erosion (Krautblatter & Moore, ; Leith et al, ; Moore et al, ). The Oeschinen rock avalanche (event A) happened during the early Subatlantic when the retreat of glaciers and presumably permafrost weakened the mountain flanks (Joerin et al, ).…”

Thermal and Mechanical Responses Resulting From Spatial and Temporal Snow Cover Variability in Permafrost Rock Slopes, Steintaelli, Swiss Alps

“…The duration of the snow‐free period influences rock stability. This can have significant impacts on rock fatigue (Jia et al , ) and affects the thermal controls of effective rock wall retreat rates (Siewert et al , ; Krautblatter and Moore, ; de Haas et al , ). Warming rock expands uniformly and fractures narrow (Cooper and Simmons, ), whereas cooling rock contracts and fractures open.…”

Recent (Late Amazonian) enhanced backweathering rates on Mars: Paracratering evidence from gully alcoves

“…Low‐magnitude rock fall processes generally occur more frequently than high‐magnitude processes, but the relative effectiveness of these processes varies between sites depending on the local conditions [ Krautblatter et al , ]. Local geological conditions that strongly influence backweathering rates include (1) lithology, (2) strength of the rock, (3) state of weathering of the rock, and (4) joint density, orientation, width, and continuity and infill [e.g., Selby , ; Krautblatter and Dikau , ; Moore et al , ; Krautblatter and Moore , ]. Many of these factors are interconnected, and weathering is indirectly included in many of these parameters, e.g., the loss of rock strength and opening of joints are largely weathering phenomena.…”