What is the Difference Between Weathering and Erosion

The main difference between weathering and erosion is that weathering is a long term process, but in contrast, erosion is a short term process.

Both weathering and erosion are geological processes. That means; these processes occur in nature, on Earth’s crust. Weathering is the breaking down or dissolving of rocks and minerals on the surface of Earth while erosion is a process where earthen materials are worn away and transported by natural forces like water or wind.

Key Areas Covered

1. What is Weathering 
     – Definition, Characteristics, Types
2. What is Erosion
      – Definition, Characteristics, Types
3. What is the Difference Between Weathering and Erosion
      – Comparison of Key Differences

Key Terms

Erosion, Rocks, Minerals, Weathering

What is Weathering

Weathering is the geological process of breaking down resources such as rocks and minerals due to the contact with the atmosphere, water, or biological organisms. The process includes the breakdown of rocks, soil, minerals, and other artificial material on Earth’s surface. Unlike erosion, weathering is an in situ process; this means, it occurs at the same place where the source lies on, and there is no movement.

Figure 1: Rock Weathering

There are two types of weathering as chemical weathering and physical weathering. Sometimes, these processes may include biological components as well; e.g., microbes. In physical weathering process, breakdown of rocks and soil occurs due to the direct contact with mechanical conditions such as heat, water, ice and pressure. Chemical weathering is caused by direct atmospheric chemicals or biological components. Physical weathering mostly occurs in very cold or very dry areas. In contrast, chemical weathering occurs in very wet and hot areas. After the completion of a weathering process, the leftovers combine with organic matter to form soil.

What is Erosion?

Erosion is a geological process that involves the transportation of geological sources from one place to another due to surface processes such as water flow. Unlike weathering, erosion involves the movement of sources such as soil from one place to another, and redeposition on a new location. Causes for erosion include dynamic activities of erosive agents such as water, ice, snow, air, plants, animals and people.

Figure 2: Erosion due to Water Flow

There are different types of erosion, depending on the causative agent—for example, water erosion, wind erosion, snow erosion, zoogenic erosion, and anthropogenic erosion. The rate of natural erosion mainly depends on the rainfall, bedrock wear in rivers, sea waves, etc. Typically, the erosion rate is higher at steep landscapes.

Generally, erosion takes place as a natural process, but sometimes it is artificial; e.g. human activities. Artificial erosion is greater compared to natural erosion, and it shows a greater impact as well.

The major form of erosion is water erosion, which occurs due to water runoff on the Earth’s crust. There are four subtypes of water erosion: splash erosion, sheet erosion, rill erosion and gully erosion. At the first stage of an erosion process, splash erosion occurs, which is followed by sheet, rill and gully erosion processes.

Difference Between Weathering and Erosion

Definition

Weathering is a geological process involving the breakdown of sources such as rocks due to the contact with the atmosphere, water, or biological organisms. Erosion, on the other hand, is a geological process involving the transportation of geological sources from one place to another due to surface processes such as water flow.

Movement

In weathering, no movement of sources, but in erosion, movement occurs followed by redeposition at a new place.

Time Taken

The process of weathering takes a long time, but erosion happens in a comparatively shorter time period.

Types

Chemical weathering and physical weathering are the main types of weathering, while water erosion, wind erosion, snow erosion, zoogenic erosion, and anthropogenic erosion are various types of erosion.

Conclusion

Both weathering and erosion are geological processes. This means these processes occur in nature on Earth’s crust. The key difference between weathering and erosion is that weathering is a long term process, but erosion is a short term process.

Reference:

1. “Weathering.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 8 Nov. 2016, Available here.

Image Courtesy:

1. “KharazaArch” By Etan J. Tal – Own work (CC BY 3.0) via Commons Wikimedia

2. “Eroding rill in field in eastern Germany” By Katharina Helming – (CC BY-SA 1.0) via Commons Wikimedia