How Aeolian Processes help to shape the surface of the earth ?

How Aeolian Processes help to shape the surface of the earth ?

Posted by Manisha on May 07, 2020

Wow !! It’s amazing !!

Do you know the reason for my amazement?

No! Let me tell you then.

Once when I was driving along with my friends across the desert, I saw the “sand dunes are moving.” Yes, I found them moving. I know you all are amazed now. Do you people or guys also wanted to know the reasons and processes behind this.

So let’s come with me on a journey to know about the potential of wind, as the main agent in shaping the surface of the earth and responsible for the movement of sand dunes and the formation of many more shapes or landforms (erosional and depositional).

Aeolian Landforms

The winds erosional and depositional activity is defined as— Aeolian processes, which also spelled as Eolian is derived from the name of Greek god Aeolus – means the keeper of wind.

  • Aeolian pertains to the wind activity in the study of Geology, especially the wind’s ability to shape the Earth's surface by it’s erosional, Transportation, and depositional work.
  • The landforms which are developed or formed by Aeolian processes (wind activities) are called Aeolian Landforms. 
  • This process (Aeolian processes) has been observed on other planets, including Mars.
  • Winds are a very useful and important medium to shape the earth's surface by it’s erosional and depositional work.

Wind can change the physical landscape or topography of Earth by carving and forming new landforms on it.

As we all know that wind is everywhere and has no boundaries. So it became a more important and effective tool in shaping the earth in those regions where water bodies (river, sea, ocean, lake) could not reach and form landforms.

Our earth’s 1/3rd areas are covered with desert.
Aeolian processes are very effective in the arid such as desert, semi-arid, and coastal region or where the land surface is ‘naked’. (Sparse or no vegetation).
As the vegetation  ( trees, plants, and grasses ) hold the soil particles into their root system and do not let them go anywhere easily, but in the absence of vegetation, wind can easily erode away the land surface and deposit it somewhere, where the speed of wind get slowed down.

  • Also, the desert areas generally receive less than 15-25 cm rainfall in a year, which made the land surface Sandy in nature, as it has a lack of moisture and is unfertile. 
  • Mainly the two reasons—a) less rainfall and b) sparse vegetation, let the winds do their carving and forming landform work easily plus effectively in an arid region (desert).
  • Like water, wind also made different landforms by it’s Erosional, Transportation, and Depositional work on weathered rocks and mass wasting materials.

These three Aeolian processes together shaped the surface of the arid region or desert. 

Chart showing three Aeolian Process
Chart showing three Aeolian Process


1. Erosion

The erosion of land which is naturally caused by the power of wind is called wind erosion.

Wind erosion is done by three processes are:

  • Attrition
  • Abrasion
  • Deflation

Attrition - When the two rock particles rub against each other and breakdown into smaller pieces, this process is called attrition.

Abrasion
- When the wind with small particles of rocks hit another big surface of rock continuously, then the rubbing of small sand particles against the rock surface is called Abrasion.

Deflation
- When the sand particles movement, together with the wind, creat hollow or depression into the surface of rock by blows away the waste (rock particles) erosion, this process is called deflation.

process causing wind erosion
The process causing Wind Erosion


2. Transportation

When the wind blows away the eroded and loose material along with it, from the flat bare areas, which has sparse or no vegetation and uncemented sediments, then this process is known as transportation work of wind.

3. Deposition

When the wind deposited all its eroded and transported material like sand, silt, and sediment, onto other faraway places, then this process is known as depositional work of wind. Wind deposit it’s material when it’s speed gets slow.

We can divide the Aeolian Landforms into two different categories, on the basis of its aeolian processes are:

Erosional Landforms of wind 
Depositional landforms of wind 

classification of aeolian landforms
Classification of Aeolian Landforms

We will discuss both of these landforms one by one in detail in my post Erosional landforms and Depositional landforms.