Erosion vs Weathering
Distinguishing the difference between erosion and weathering becomes easy when you understand these two different processes. Erosion and weathering are natural geological forces of nature that cause the destruction of rocks and shape the surface of the earth. However, we can say that these processes are similar in nature in the sense that they take part in changing the topography of the surface of the earth, but there are differences that need to be highlighted. Weathering refers to breaking up of rocks into smaller fragments as a result of forces of nature while erosion is a set of processes that involve winds, flowing water, and movement of ice glaciers that take along the fragments created by weathering to newer locations.
What is Weathering?
In weathering, large rocks get broken because of the action of weather, but they do not move to a new location. They simply remain next to one another. Weathering is classified as biological, physical and chemical weathering. Physical weathering is all those processes that lead to breakage of rocks into smaller pieces such as collision, fracturing because of pressure, or release of pressure caused by erosion of top level rocks. Breaking that takes place because of inward growth of roots of plants and so on is known as biological weathering. Chemical weathering, on the other hand, is a result of water, either through rainfall or from high streams, oxygenation of minerals present in rocks, or when minerals in rocks dissolve completely in water. As a result of all these actions rocks break into smaller pieces.
Here, let us see how one process actually happens. Let us see how physical weathering takes place. You must have seen how there are crevices and cracks on huge stones. When it rains, water gathers in these cracks and crevices. Then, when night time comes, the temperature of the environment drops. As a result of that, the water that is in these small cracks and crevices begin to expand as it turns to ice. In doing so, the rock starts to split. This action repeats for some time, and finally, the rock piece separates itself from the huge rock.
What is Erosion?
When the broken up rock pieces remain where they are, the action of wind, water, and melting ice takes some of these small pieces of rocks to new locations. This process is called erosion. Erosion is a set of processes that result in shaping of the landscape as rock pieces are brought down to lower levels by blowing winds, flowing water, and the effects of gravity. The small pieces of rocks that we see around beaches and sides of rivers have origins high up in the mountains. Erosion is the beginning of a larger process. It has four other phases known in order as detachment, entrainment, transport and deposition. The pieces of rocks and sediments that start travelling with erosion have to settle somewhere. Once they do, that is known as deposition.
What is the difference between Erosion and Weathering?
• Though both weathering and erosion help in reshaping the surface of the earth, weathering is involved in breakage of rocks into smaller pieces while erosion is the movement of these smaller fragments to newer locations as a result of blowing winds, flowing water, and melting ice coupled with gravity.
• Weathering can be physical, organic, or chemical whereas erosion is plain movement of rock pieces from one place to another.
• It is because of both weathering and erosion that we get to see new geological features. We cannot stop weathering from happening. However, to stop erosion from happening people take different actions such as planting trees on hill tops.
Both weathering and erosion are a continuous process that keeps on acting, all the time,on the surface of the earth. In that, first weathering takes place and then the erosion takes the broken rock pieces to new locations. These are natural processes that continue unabated. Both weathering and erosion are constantly at work to reshape the surface of the earth into mountains, valleys, rivers, and plains that are known as physical features. These physical features keep on changing on the geological time scale as a result of both these natural geological processes.
Images Courtesy: