Physical Weathering

Physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water.

There are two main types of physical weathering:

• Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
• Exfoliation occurs as cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.

Where does it occur?

Physical weathering happens especially in places places where there is little soil and few plants grow, such as in mountain regions and hot deserts.

How does it occur?

Either through repeated melting and freezing of water (mountains and tundra) or through expansion and contraction of the surface layer of rocks that are baked by the sun (hot deserts).