Weathering

Earth's surface changes through time. Its surface is different from what it used to be hundreds of years ago. Some parts of the land may have been higher and more rugged than they are now. Such changes could have been caused by various forces present in nature such as water, wind, ice, heat, pressure and even living things.

These forces continuously shape the land by breaking down or wearing away rocks in the process of weathering. The effects of weathering are clearly seen whenever a rock is exposed to the environment. They may be evident as a crack or break in the rock, or as a chemical reaction that slowly changed the composition of the rock.