The wind moulds aeolian landscapes (named for the Greek God of wind, Aeolus). Aeolian processes involve the wind carrying, depositing, and eroding sediment. Numerous habitats, including the coastal zone, chilly and scorching deserts, and agricultural areas, are where these activities take place. A lack of vegetation cover, a supply of fine sediment (clay, silt, and sand), and strong winds are common characteristics of these ecosystems.
The emission and/or mobilisation of dust and the development of sand dunes are both caused by aeolian processes. In order to carry sediment, they rely heavily on other geologic processes including rivers, glaciers, and waves. In all terrestrial ecosystems, the wind is a geomorphic agent. It is most active where there is little to no vegetation, fine-textured soils and sediments, and a dry climate. Through both sediment erosion and deposition, aeolian processes produce a number of distinctive features. These are:
- Mushroom Tables
- Deflation Hollows
- Sand dunes
Aeolian Landforms Wind Action
In scorching deserts, the wind is the primary geomorphic force. Winds blow more quickly in hot deserts, which leads to erosion and deposition in the desert. Aeolian Landforms are landforms produced by the wind’s erosional and depositional processes. This mechanism has been observed and researched on other worlds, including Mars, and is not specific to the Earth.
An erg is a wide, flat stretch of desert covered with wind-swept sand with little to no vegetation cover
(also known as a sand sea, dune sea, or sand sheet if it lacks dunes). It is characterised as a desert region with more than 125 square kilometres of aeolian or wind-blown sand and more than 20% of the surface covered with sand. “Dune fields” are smaller regions. There are multiple ergs in the Sahara, the world’s largest scorching desert.
Deserts are arid regions of the landscape with minimal precipitation, making it difficult for plant and animal life to survive. The lack of vegetation exposes the exposed ground surface to denudation processes. The world’s land surface is roughly one-third arid or semi-arid. This comprises a large portion of the Polar Regions, which are called ‘’cold deserts” because they receive minimal precipitation. According to the amount of precipitation that occurs, the average temperature, the factors that contribute to desertification, or their geographic location, deserts can be categorized. Deserts make up about one-fifth of the earth’s surface. True deserts are those that are completely devoid of any vegetation.
The main causes of the desert’s aridity are insufficient and irregular rainfall, high temperatures, and a quick rate of evaporation. The vast majority of deserts sometimes referred to as trade wind deserts or tropical deserts are restricted to an area between 15 and 30 degrees parallel to the equator.
On the western coasts of the continents, they are located in the trade wind belt.
Offshore trade winds frequently encounter cold currents, which has the effect of desiccating (dehydrating), making it difficult for moisture to condense into precipitation.
Aeolian Landforms Erosional
Aeolian Erosional Landforms are explained below:
Rocks that have been eroded, pitted, etched, grooved, or polished by ice crystals or sand carried by the wind are known as ventifacts. These geomorphic landforms are often found in desert regions where there is minimal vegetation to obstruct the movement of aeolian particles, strong winds are common, and there is a steady but manageable supply of sand. Ventifacts that resemble mushrooms include mushroom tables and mushroom rocks. In deserts, the winds carry more sand and rock particles near the ground, which leads to more bottom erosion in underlying rocks than top erosion. As a result, slender rock pillars with broad top surfaces that resemble a mushroom were formed.
Pediplains are high-relief structures in deserts that have been eroded by the wind into low, featureless plains.
Deflation is the process through which wind action clears away loose debris from the ground. Deflation hollows are created when sustained wind motions induce a shallow depression as a result of deflation. Blowouts, also known as deflation basins, are hollows created as the wind removes particles. Although they can have a diameter of up to several kilometres, blowouts are typically tiny.
Yardangs are ridge-separated parallel troughs carved into the softer rock that runs in the direction of the wind. The predominant wind’s direction can be determined from the yardangs.
Some of the blow-outs become deeper and wider and are suitable to be dubbed caverns as wind-borne sand strikes the rock sides.
A Zeugen is a conspicuous, tabular pile of durable rock in the desert. Typically, layers of both hard and soft rocks alternate.
Aeolian Landforms Erosional Diagram
Below are the diagrams for various Aeolian Erosional Landforms:
Aeolian Landforms Depositional
Sand dunes are formed well in hot deserts. There are two major types of sand dunes:
Barchans and Seifs, depending on the shape of the dunes. Barchans, also known as crescent-shaped dunes are the most prevalent type.
The difference between a barchan and a seif:
|These are crescent-shaped dunes.||These are linear in shape with two slip faces.|
|Barchan dunes may reach a height of more than 90 feet.||Seif dunes reach up to 300 feet in height.|
|These dunes occur all around the world where sand dunes occur.||Seif dunes mostly occur in the open desert.|
|They are formed in areas where the amount of sand is moderate and the wind blows only in one direction.||These are formed when the barchan dune moves in more than one direction.|
Wind-transported silt that has accumulated from dust storms over many thousands of years has blanketed the surface of various sizable regions of the earth. These filings are referred to as Loess.
They are regular, wave-like undulations that are parallel to the direction of the dominant wind.
Aeolian Landforms Depositional Diagram
Below are the diagrams for various Aeolian Deposionall Landforms:
Aeolian Landforms UPSC
Deserts are areas with low levels of precipitation (below 25 cm yearly), making them unfavourable environments for both plant and animal life. Deserts can occur in plains or mountains, and they can be hot, arid, semiarid, coastal, or frigid. It is one of the main ecotypes on Earth and is home to a variety of unique plants and animals that have evolved to survive in harsh environments.
A UPSC aspirant should be well versed with the topic of the Evolution of various Landforms like Glacial, Fluvial, and Aeolian. This topic of geography holds immense importance from both Prelims and Mains’ point of View. The details in the article would help candidates prepare for UPSC 2023.
Aeolian Landforms FAQs
Q) What is a Desert?
Ans. A desert is a desolate and barren region of the landscape with minimal precipitation, making living circumstances unfriendly for both plant and animal life.
Q) What is meant by Loess?
Ans. Wind-transported silt that has accumulated from dust storms over many thousands of years has blanketed the surface of various sizable regions of the earth. These filings are referred to as Loess.
Q) What are the types of sand dunes?
Ans. There are two types of sand dunes, such as Barchans and Seifs, depending on the shape of the dunes. Barchans, also known as crescent-shaped dunes, are the most prevalent type. Barchans and Seif are comparable, however, Seif only has one wing or point.
Q) Name the Largest desert in the world.
Ans. Sahara, A desert on the continent of Africa is called the Sahara. It is the largest hot desert in the world and the third-largest desert overall with an area of 9,200,000 square kilometres, second only to the deserts of Antarctica and the northern Arctic in size.
Q) Where is the Gobi desert located?
Ans. The Gobi Desert basin spans southern Mongolia and northwest China.
Q) Which desert is located in India?
Ans. Thar desert is located in Rajasthan and the Cold desert is located in Ladakh.
Other Indian Geography Topics
Other Fundamental Geography Topics