Answer – Frost wedging is a process wherein rocks disintegrate due to repeated freezing and thawing of water trapped in their cracks/pores.
Explanation:
Commonly observed in areas with high moisture and very low temperatures, frost wedging is a form of physical weathering (where the chemical composition of rocks is not altered).
When water seeps into rock crevices and freezes, it expands (since ice has 9% more volume than water). This expansion occurs in a limited space, creating a high pressure, which in turn widens the crevice. Over a period of time, repeated freezing and thawing makes the crevice/pore bigger, eventually breaking the rock down into smaller sediments.
Thus, frost wedging can be defined as the mechanical disintegration of rocks that is the direct result of water freezing and thawing in crevices/pores.
There are a few important factors that contribute to rocks’ susceptibility to frost wedging. One is the type of rock. Sedimentary rocks tend to weather quicker from frost wedging than igneous ones. Similarly, rocks with larger pores are more likely to break down from it than those with smaller pores. Also, greater the severity, length, and frequency of freeze-thaw cycles, greater is the extent of frost wedging.
