Types of Weathering
There are three different types of weathering: mechanical, chemical, and biological. Mechanical weathering refers to the direct break-up of a material. Next, chemical weathering is the weakening of a material on the atomic level. Biological weathering combines the two. It includes any action taken by a living thing that wears down a material.
Three Types of Weathering
As stated, there are three types of forces which weather materials. But, these are huge categories and they overlap. Let’s try and focus on each one in-depth, one at a time.
In most northern states, roads are subject to temperature shocks. This is a form of physical weathering that happens over the course of several months. During the summer, when the sun is out, it’s relatively hot. This causes the material which makes up a road to expand. As it does, it will crack and fracture. Several months later, in the winter, temperatures drop. The road will then contract which is another source of cracking.
In desert environments, heavy winds tend to pick up lots of sand. This creates what is known as a sandstorm. Importantly, sandstorms spew out sand as they collect it. While each sand particle is tiny, lots of them make for a powerful force. They’re thrown against boulders, each one damaging the rock a little. Over time, this can chip pieces off of the boulder.
This next type of weathering is a little more complex. Physical weathering isn’t that hard to explain: rocks can be broken with force. But, chemical weathering is different. It takes place at the level of atoms and molecules. As a result, it’s invisible to us. Yet, its impact is not. Let’s look at a few examples of what it can do.
We don’t usually think of rain as dangerous or destructive. And for the most part, it’s not. But, sometimes it’s more than water that rains down. Above industrial zones, for example, chemicals float up into the sky. When it rains, they mix with the water coming down.
Have you ever left something metallic out in the rain, say a bike? If you did, you may have received an unpleasant surprise: the metal rusted. Rusting is something that happens to metals exposed to rain or open air. It’s when oxygen (in water and air) reacts with metal. So, we also call the process oxidation.
Now, our final type of weathering is much easier to observe. That’s because it has to do with living things! For example, some animals tunnel through dirt to find food. Additionally, most plants release waste chemicals into the environment. Both of these behaviors are examples of biological weathering.
Other Great Resources:
Geography4Kids on the Types of Weathering: http://www.geography4kids.com/files/land_weathering.html
‘Weathering Facts for Kids’ by Kiddle: https://kids.kiddle.co/Weathering
Physical Weathering in the Rock Cycle: https://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3561.html