How does wind change the earth’s surface? The surface of our planet, a constantly evolving arena shaped by a multitude of natural forces, is always transforming.
The wind, a truly remarkable force of nature, perpetually alters the Earth’s terrain, giving rise to a multitude of stunning and unparalleled geographical characteristics.
And you will also be amazed when you see someone describe how wind and water alter the earth’s surface. So, how does it all work?
Wind changes the earth’s surface through the wind-driven erosion, transportation, and deposition of particles.
The Role Wind Plays in the Changing Landscape of Earth
The winds both sculpt and shape landmasses via several distinct processes collectively termed aeolian, named after the Greek god, considered the keeper of the wind.
They include erosion, transportation and deposition of sediments and occur in a variety of environments across the planet.
It has hot and cold deserts and coasts but depends on there being a geomorphic agent, such as:
- A river
- A glacier
- Waves to supply dust and sediments
Science is still uncovering how these processes affect specific environments, such as those found on the high Tibetan Plateau, and how they impact entire regions.
An Important Consideration
Some of these processes have been happening continuously since the dawn of geographical time.
But others have stalled as conditions changed, perhaps as a river changed its course, water is a more powerful aeolian force.
But, it is the wind-driven processes that dominate in arid conditions.
How Does Wind Change the Earth’s Surface?
Wind, with all its power, can have a significant impact on altering the landscape of the earth.
The whole process takes place in different ways, including the following:
Wind Leads to Erosion and Weathering
The wind has the potential to cause weathering everywhere, even in big cities, weakening structures over time. It is a mechanical process.
But, how does wind erosion change the earth’s surface? Well, in simple words, wind acts like a hammer.
It chips away at any material in its path and manages to find weaknesses in even the most durable such as steel, stone, cement and rock.
The dusty debris is blown away to eventually make it into the water courses to be deposited somewhere else.
In the meantime, the original material is left open and vulnerable to chemical erosion.
Fact: The process of wind erosion produces awe inspiring effects in nature, for example the parallel dunes of south-west Queensland.
Types of Wind Erosion
Wind erosion is an important process and it is divided into different types, including the following:
- Suspension
- Saltation
- Creep
Suspension
Soil is vulnerable to wind erosion. It moves the particles when smaller than 0.1mm by supporting them in the air as in a suspension.
Saltation
Alternatively, they move across the ground’s surface by saltation and creep. Saltation moves particles from 0.1- 0.5mm in size.
These medium-sized soil particles hop or bounce along, being too heavy to be suspended. As the bounce, they cause more erosion.
The larger particles, those over 0.5mm although still small, are too heavy to leave the ground at all and creep along by rolling.
This is also how larger particles move, although they might only move a few feet.
Creep
Creep is very dynamic, particles bump into each other and dislodge and gather more particles from the surface adding further to the scale of erosion.
This in turn throws more particles into suspension that are sometimes deposited far from their original location, across an ocean on a different continent.
Wind Erosion Can Cause Damage
Wind erosion can and does cause extensive damage. It is not just that the wind works into tiny cracks to force materials apart.
But, the particles act as abrasives that are repeatedly rubbed, scratched and scored along every exposed surface.
Some materials fare better than others under the onslaught. But, due to climate change, you are likely to see winds severe enough to damage homes and infrastructure.
Therefore, it is important to develop and test a range of tougher more durable materials to prevent the damage resulting from wind erosion.
Fact: Farmers are already taking preventative steps to save their soil because its loss costs US agriculture around $44 billion a year.
Wind Turns Rock into Natural Structures
There are no rocks that resist weathering. Even the hardest like granite, will eventually wear down and have its particles carried away.
Although human activity speeds up weathering, it is a natural process that has sculpted many natural wonders around the Earth.
And that is certainly not limited to the dunes in Queensland’s Simpson National Park.
Examples of Wind Creation Natural Structures
There are the yardangs in Hami Basin in eastern Xinjiang, China.
A world heritage site with natural wind-made structures comprised of sediments laid down during the Cretaceous, Jurassic and Tertiary periods.
The formations cover tens of miles and resemble a fleet of ships. Utah’s Delicate Arch is another example.
A single structure standing almost 46 feet tall, and the Grand Canyon in Northern Arizona is some 277 miles long, 18 at its widest point.
As the winds shaped the sides of the canyon over millennia, the Colorado River eroded its way down to over a mile.
Wind Deposits Material in New Places
Another way wind changes the earth’s surface is through depositing materials in new places.
The particles fall out of the air currents to form characteristic ripples and dunes, however, 45% of all the deposits form flat sand sheets.
An Example to Consider
There is an example at Selima, in southern Egypt. Today it is a dry, barren empty expanse but it used to have a population, water and vegetation.
The Selima Sand Sheet is a broad aeolian plain forming around 74,600 square miles of hyper-arid desert near the border with Sudan.
The surface is covered by a mix of coarse lag granules and fine sand although the expanse is spotted with giant chevron-shaped sand ripples and dune fields.
The dunes move with the wind by saltation and creep when the grains reach the dune’s peak, they tumble down the slip face.
Fact: Sand is also picked up and carried in sandstorms, which is evident in North-east Africa where the Khamasin winds can lift fine particles almost three miles into the air.
Wind Can Transport Material Long Distances
The Khamasin and other desert winds such as in the Sahara, transport particles long distances in regular events that coincide with Spring’s rising temperatures.
It is not unusual for Saharan sand to fall over central Europe. The Khamasin winds drop brown rain in winds that reach 68mph.
If they move west, they have the potential to destroy the coral reefs of the Caribbean. It is not just sand that is carried, there are various silts, clays and biological matter.
Some will be suspended for many days either in the bed load moving by creep and saltation or in suspension.
An Important Consideration
The large particles are deposited first when the wind meets an obstacle and slows and so there are different kinds of deposits.
Because of their size and weight, silt and clay fall out separately to eventually form loess, a rich soil.
Deposits of silt and clay also form muddy deposits on the seafloor.
Controlling Damage from Wind Erosion
We need the wind. It is how nature distributes the Earth’s natural resources, such as soil and moisture around the planet.
However, global warming looks set to upset the natural balance and high winds are expected to happen more frequently, be more severe and more destructive.
Winds are already affecting so many industries and aspects of life, such as:
- Agriculture
- Global food supplies
- Transportation
- Energy production
- Leisure and tourism
Future recovery costs will run into the billions. 2022 was another bad year for the US, now experiencing a trend that is financially untenable.
Steps Taken to Deal with Wind Damage
Worldwide, steps are being taken to control wind erosion by:
- Installing wind breaks and barriers, fencing, walls and banking
- Planting annual and perennial grass barriers
- Reducing fields size, planting hedgerows and trees
- Laying down aggregates, roughing the land, trapping blown soil
- Covering areas with polymeric emulsions, avoiding compacting and overgrazing
Fact: In the last seven years there have been 122 wind-erosion events and each has cost over a billion dollars.
Takeaway
How does wind change the earth’s surface? Wind remains a compelling artist, leaving its mark on the Earth’s terrain in various ways.
The significance of wind in shaping our planet’s ever-changing surface morphology is highlighted by its ability to transform landscapes.
By delving into the examination of wind’s influence, we get to learn more about the enthralling interplay between the Earth’s terrain and the encompassing atmosphere.
