Connwood Foresters, Inc.

About forestry service, 11975, Wainscott, NY, US, Connecticut

A rockfall or rock-fall is a quantity of rock that has fallen from a cliff face or from the roof or walls of mine or quarry workings. == Causal mechanisms == Favourable geology and climate are the principal causal mechanisms of rockfall, factors that include intact condition of the rock mass, discontinuities within the rockmass, weathering susceptibility, ground and surface water, freeze-thaw, root-wedging, and external stresses. A tree may be blown by the wind, and this causes a pressure at the root level and this loosens rocks and can trigger a fall. The pieces of rock collect at the bottom creating a talus or scree. Rocks falling from the cliff may dislodge other rocks and serve to create another mass wasting process, for example an avalanche. A cliff that has favorable geology to a rockfall may be said to be incompetent. One that is not favorable to a rockfall, which is better consolidated, may be said to be competent. In higher altitude mountains, rockfalls may be caused by thawing of rock masses with permafrost. In contrast, lower altitude mountains with warmer climates rockfalls may be caused by weathering being enhanced by non-freezing conditions. == Propagation == Assessing the propagation of rockfall is a key issue for defining the best mitigation strategy as it allows the delineation of run out zones and the quantification of the rock blocks kinematics parameters along their way down to the elements at risk.