Page 155 - SST Class 07

When the glacier starts melting, its capacity to Wind Erosion
carry load is reduced. Thus, rock materials are Wind is a stronger erosional force in arid regions
deposited on the sides and floor of the valley. than it is in humid regions because winds are
These deposits form glacial moraines. stronger. In humid areas, water and vegetation

WORK OF WIND bind the soil so it is harder to pick up. In arid
Wind transports small particles, such as silt and regions, small particles are selectively picked up
clay, over great distances, even halfway across a and transported.
continent or an entire ocean basin. Particles may Deflation
be suspended for days. Wind more easily picks As small particles are removed, the ground
up particles on the ground that has been dis- surface gets lower and rockier, causing deflation.
turbed, such as a construction site or a sand What is left is desert pavement, a surface covered
dune. Just like flowing water, wind transports by gravel-sized particles that are not easily
particles as both bed load and suspended load. moved by wind.
For wind, bed load is made of sand-sized parti-
This desert pavement formed in the Mojave
cles, many of which move by saltation. The Desert as a result of deflation.
suspended load is very small particles of silt and
clay.

Suspension

Wind

Saltation

Creep

Deflation
Bed Load-Wind Transport by Abrasion
Suspension, Saltation and Creep
Particles moved by wind do the work of abra-
sion. As a grain strikes another grain or surface it
erodes that surface. Abrasion by wind may polish

Sandstrom
In a sandstorm, sand is usually within a meter of
the ground. A dust storm’s smaller particles can
travel higher. Abrasion

Social Science-7 155