Download Aim: How can we describe erosion caused by running water, wind

Aim: How can we
describe erosion
caused by running
water, wind, and
glaciers?
Wind Erosion
 Sandblasting (abrasion) –
occurs when winds blow sand or
silt grains against rocks and
other objects
 Lower portions of rocks become
more eroded
 Creates rounded and frosted
sediments
Glacier Erosion
 Glacier – naturally created
mass of ice and snow, moves
under influence of gravity
 Act like a “river of ice”
 Creates parallel scratches
and grooves in rock as it
moves.
Direction of grooves
shows direction of
movement
Carves a U-shaped valley
Creates semi-rounded
and scratched sediments
Running Water Erosion
 Most common erosion type
 Includes rivers, streams, and
waves
 Greater velocity transports
larger particles
 Creates smooth and rounded
sediments
Top View of River
Cross Section of
River at dashed lines
▲
▲
▲
▲ indicates
the fastest
velocity
DELTA
 Streams carve v-shaped valley’s
 Three factor’s determine stream
velocity:
 Gradient – the steeper the slope, the
faster the river
 Discharge – the more water, the faster
the river
 Stream Channel Shape – wide rivers
run slow, narrow rivers run fast
What is the minimum rate of flow at which
a stream of water can maintain the
transportation of sediments?
Diameter
6.4 cm
0.2 cm
1.0 cm
25.6 cm
Rate of Flow
Name each particle size according
to page 6 of the ESRT:
Diameter
0.008 cm
0.5 cm
0.0002 cm
7.5 cm
36.2 cm
5.3 cm
0.003 cm
Particle Size Name
Erosion Caused by Gravity
 Everything that goes up……
 ….must come DOWN
 Mudslides, landslide, rockslides and
rockfalls are examples of erosion caused
by gravity.
 AKA Mass movement