The four types of physical weathering are:
1.) Frost action or freeze-thaw weathering
2.) Exfoliation or unloading
3.) Thermal expansion and contraction
4.) Abrasion
These types of weathering are similar in that they all involve physical processes that break down rocks and other geological materials without the involvement of chemical reactions.
Frost action occurs when water seeps into cracks in rocks and freezes, causing the water to expand and exert pressure on the surrounding rock. This process repeats over time and can cause the rock to fracture and break apart.
Exfoliation occurs when rocks that were once buried deep beneath the earth's surface are exposed to lower pressures as overlying rocks erode away. As the pressure decreases, the rocks expand and crack, causing outer layers of rock to peel away like layers of an onion.
Thermal expansion and contraction occurs when rocks are repeatedly subjected to heating and cooling cycles. This can cause the rock to expand and contract, leading to the development of cracks and fractures.
Abrasion occurs when rocks and other geological materials are subjected to repeated rubbing or grinding by other materials, such as wind-blown sand, water, or other rocks. This process can cause rocks to wear down and break apart over time.
In summary, these four types of physical weathering are similar in that they all involve physical processes that break down rocks and other geological materials, but each type operates under different conditions and results in different forms of weathering.