Slice Weathering in the Aletsch Forest

The frost weathering (including frost wedging) is caused by the volume expansion of freezing water, contained in pores and crevices. It is one of the most important processes of physical weathering. Comparatively small forces are sufficient to separate blocks limited by fissures and bedding planes from the massive bedrock. Meanwhile much more force is needed to produce new crevices in the solid bedrock. The process of removal of blocks from the massive rock is called block decay.