Water shapes the land

23-3

Sediment• Dirt and dust from the earth

washed away by water. • As water washes sediment away

it is eventually deposited.• Deposition is the process in

which sediment is laid down in new locations

The Miss. River

deposits sediment from the continent into the Gulf of Mexico.

Water erosion• Streams of water carries sediment

suspended in it.• Saltation is when particles bounce

along a stream bottom. • Faster a stream moves the more

sediment it can carry – increasing abrasion.

• A stream ability to erode depends on its speed

Water Erosion

• Water collects sediment and deposits it where the current slows – usually at the river’s mouth

• Ex. – Mississippi Delta

This stream starts in the Rocky

Mountains winds through this

valley and ends in the Gulf of

Mexico carrying sentiment as it

goes.

Water over time will cut through rock and deposit it

downstreamAs the Colorado River has here in the Grand Canyon

Groundwater Erosion• Includes sinkholes and caves• Caves are carved into soft stone

usually below the water table• Stalagmite – If the water and minerals

drip to the floor a pillar forms• Sinkholes - erosion weakens

limestone under the ground causing a weak spot.

This tunnel in The Cave of the

Winds was created by

ground water washing away

the weaker stone. Eventually this

area became dry and left a cave.

These are Stalactites they

form when water mixes

with minerals and drip from a

cave ceiling

Glaciers form where snow falls but does not melt.

Two Types

Continental – thick sheet of ice

Valley – found on mountains

Glaciers scrap off sediment and reposition it as they melt.

Wind Erosion• Wind scours surface like

sandpaper and removes loose sediment

Garden of the Gods in Colorado