Earth’s Surface
Erosion
Vocabulary

Erosion- the
process that
wears down
and carries
away rocks
and soil
Erosion

Gravity acts as a
force of erosion
by causing a
mass movement
• Mass
movement- a
process that
moves
sediment down
a hill
Mass Movement

Landslide- a
rapid
movement of
large
amounts of
rock and soil
Mass Movement

Mudflow- a
rapid
downhill
movement of
a mixture of
water, rock
and soil
Mass Movement

Slump- mass of
rock and soil
suddenly slips
down a slope
• This is different
from a landslide
because it comes
down in one
large mass
Mass Movement

Creep- a very
slow movement
of rock and soil
• Usually creeps
cause objects
to sit at
unusual angles
Water Erosion


Stream- a channel along which water
continually flows
River- a large stream usually forming from
several streams flowing together
Features of Streams


Flood Plain- a flat area along a stream
that is entirely covered only during times
of floods
Meander- the winding and bending of a
stream as it erodes the land
• Only older streams do this

Oxbow Lake- when sediment builds up,
cutting off the meander from the rest of
the river, causing a separate, curved lake
Water Erosion

Fast moving
rivers that are
straight and
narrow cut steep
slopes and
create a Vshaped valley
• ExampleGrand Canyon
Grand Canyon
Water Erosion

Waterfall- a river
cuts through soft
rock faster than
hard rock
• Example- Niagara
Falls
Niagara Falls
Groundwater Erosion


A form of chemical erosion
Makes caves and sinkholes
• CAVE- limestone erodes away,
leaving behind a dry narrow
passage
• SINKHOLE- weakened limestone
where the entire portion of the
ground suddenly collapses
Glacial Erosion

Glaciers erode land
in 2 ways
• Plucking- as a
glacier flows over
land it picks up
rocks
• Abrasion- gauges
and scratches in
rocks as a glacier
drags across land



Causes large, bowl
shaped valleys
called cirques
Cuts U-shaped
valleys in
landforms
May leave behind
large, cold glacial
lakes
Wind Erosion

Deflation- wind picks up and carries away
small particles
• The faster the wind, the larger the
particles it can carry
Example- Sand dunes