Wind Erosion

Wind does not have the same energy to

erode and transport larger fragments as

glaciers.

It is only usually strong enough to pick up and

transport sand and fine sediments.

Beaches and deserts are especially

susceptible.

Wind Erosion

Occurs when sand and silt particles are

removed from one area and blown against

rock surfaces or other objects.

When the particles are removed it leaves a

slightly lowered or hollowed area. This

process is known as deflation

Hamada

Level, rocky desert

that has been

smoothed by

abrasion.

Found in parts of

Northern Africa.

Abrasion

The surfaces of hamadas are smoothed

by the force of abrasion.

Wind-borne particles sand blast and wear

away the surface.

This tends to occur close to ground.

Erg

An Erg is a huge

sandy area where

dunes are built by the

wind. Dunes are

always moving : sand

grains are pushed by

the wind and roll one

over the other. Some

move slowly, other

faster.

Erg Continued

Sand Dunes – the most common

landscape feature in ergs. They are

crescent or triangle shape pile of sand

deposited when the wind stops blowing.

Size and shapes can vary.

Barchan

A crescent shaped dune with horns or

arms streaming out at either side pointing

the direction of the wind

They have been known to exceed more

than 30m in height.

Barchan Dune

Loess

Refers to any unconsolidated, non-stratified, soil composed primarily of silt sized particles.

It is very fertile agricultural soil.

It occurs when wind transports and deposits dust, clay, and silt. These collect in a series of layers and become a loess.

Winds moving across the outwash of the

Matanuska River valley, Alaska, carry the

silt fraction to produce loess.