Weathering

The different surfaces of the Earth are often changed through a process called weathering. Weathering is the breaking down of the materials of the Earth's crust into smaller pieces or particles.

There are two types of weathering, physical and chemical. Physical weathering is when the Earth's crust is exposed to water, air, and temperature changes. This can occur immediately or over a long time period. There are many examples of physical weathering including streams cutting through rock to form canyons, rocks splitting when water seeps in and freezes, windblown sand breaking down rock, roots from plants breaking apart the rocks in soil, and even animals.

Water from streams or rivers dissolves the minerals from the Earth's crust, and the moving water acts as a force breaking down the pieces of rock into smaller and smaller pieces. A small stream can cut through softer rock, forming canyons. A canyon is a deep valley with steep sides, often with a stream flowing through it. The flowing water can also smooth and sculpt the harder rock. The physical weathering takes place over millions of years resulting in the formation of a canyon.

If the temperature drops low enough, rainwater can freeze and expand, causing cracks in rocks, splitting the rocks apart. Following a rain, the water enters the cracks of rock, then freezes due to the low temperatures. The ice expands and takes up more space, causing the physical weathering to take place.

Winds may cause much damage to the Earth along with rain and extreme temperature changes. The wind acts as a force and blows sand and other bits of rock over the Earth's surface and can also wear away other rocks.

Plants and their roots can also cause rocks to weather and erode. The roots or parts of a plant can make its way into a crack in a rock and as it grows it can break apart the rock.

Earthworms and groundhogs, and other burrowing animals, can also contribute to physical weathering. The Earthworms and other burrowing animals loosen the soil and can break apart the rocks in the soil. Moles, rabbits, gophers, and even ants can also cause physical weathering to occur in soil.

The second type of weathering is called chemical weathering. Chemical weathering occurs when chemicals affect the Earth's crust, whether found in the air or in the water. One example includes rain mixing with chemicals in the air causing rust. Rust is formed when the oxygen in the air reacts with iron. This is an example of chemical weathering and can affect metal objects.

Another example of chemical weathering occurs when the chemicals in the air such as oxygen, carbon dioxide, sulfur dioxide and others cause acids to eat away at rocks. Salt can also cause chemical weathering as it can damage many objects and affect surfaces of the Earth.

In summary, there are two types of weathering that affect the Earth's surface and other objects. Physical weathering is when the Earth's crust is exposed to water, air, and temperature changes. Chemical weathering occurs when chemicals affect the Earth's crust, whether found in the air or in the water. Physical weathering takes place over millions of years resulting in the formation of deep valley with steep sides called a canyon. Chemical weather can cause rust to destroy metal objects. Weather causes many changes take place on the Earth's surface.