Agents of erosion and deposition
description
Transcript of Agents of erosion and deposition
AGENTS OF EROSION AND
DEPOSITION
Chapter 12
12-1 Shoreline Erosion and Deposition Wave Energy
Wave Trains○ Waves move in
groups at regular intervals away from their source
○ When water gets shallow they change form and break Increased height and
closely spaced
12-1 Shoreline Erosion and Deposition Wave Energy
Wave Trains○ Wave Period
The interval between braking waves
Usually between 10-20 seconds long
12-1 Shoreline Erosion and Deposition Wave Energy
Pounding Surf○ Waves have enough
energy to break rock ○ Pick up loose sand
and wears down coastal rock
○ Moves material
12-1 Shoreline Erosion and Deposition Wave Deposits
Beaches○ Any area of shoreline
made up of material deposited by waves
○ Colors and textures can varyDepends on source
of material
12-1 Shoreline Erosion and Deposition Wave Deposits
Wave angle○ Movement of sand
depends on wave angle
○ Perpendicular to the shore moves the sand in a zigzag pattern
12-1 Shoreline Erosion and Deposition Wave Deposits
Offshore Deposits○ Longshore current
Movement of water near or parallel to the shoreline
○ SandbarUnderwater ridge of
sand, gravel, or shells
○ Barrier SpitExposed sandbars
that connect
12-1 Shoreline Erosion and Deposition Wave Erosion
Sea Cliffs○ Form when waves
erode and undercut rock
○ Produce steep slopes○ Rate depends on
material
12-1 Shoreline Erosion and Deposition Wave Erosion
Sea Stacks○ Offshore columns of
resistant rock○ Were once part of
mainland Sea Arches
○ Continued erosion of a sea cave
12-1 Shoreline Erosion and Deposition Wave Erosion
Sea Cave○ Waves that cut holes
in rock along a cliffHeadland
○ Finger-shaped projection on a shoreline
Wave-cut Terrace○ Sea cliff that is worn
back to a level platform
12-2 Wind Erosion and Deposition Process of Wind
ErosionSaltation
○ The movement of sand-sized particles by a skipping and bouncing action
○ Happens in the direction the wind is blowing
12-2 Wind Erosion and Deposition Process of Wind
ErosionDeflation
○ The lifting and removal of fine sediment by wind
○ Leaves behind larger rock fragmentsDesert pavement
12-2 Wind Erosion and Deposition Wind Erosion and
DepositionAbrasion
○ The grinding and wearing down of rock surfaces by other rock or sand particles
○ Occurs in areas of strong winds and loose sand
○ Will erode, smooth, and polish rocks
12-2 Wind Erosion and Deposition Wind-Deposited
MaterialsDunes
○ Mounds of wind deposited sand
○ Wind slows down when it hits plants or rocks
○ Will drop heavier material
12-2 Wind Erosion and Deposition Wind-Deposited
MaterialDunes
○ Move in the direction of the prevailing winds
○ Usually have a sloping side and a steep sideSlip face
- Steep side where material falls
12-2 Wind Erosion and Deposition Wind-Deposited
MaterialLoess
○ Deposit of fine-grained sediment
○ Feels like talcum powder
○ Usually found far from their source
○ Great for crops
12-3 Erosion and Deposition by Ice Glaciers
An mass of moving ice
Erode, move, and deposit large amounts of rock material
Form in areas where snow is year round○ Weight of snow
compacts snow into ice crystals
12-3 Erosion and Deposition by Ice Glaciers
Alpine Glaciers○ Forms in mountains○ Valley glacier
Form in valleys originally created by stream erosion
Flow slowly downhillCreate broad U-
shaped valleys
12-3 Erosion and Deposition by Ice Glaciers
Continental Glaciers○ Spread across
continents○ Continental Ice Sheet
Huge continuous mass of ice
Continue to get larger over time
12-3 Erosion and Deposition by Ice Glaciers
Ice Shelves○ Area where ice is
attached to the ice sheet but rests on open water
○ Will create icebergs when pieces break off
12-3 Erosion and Deposition by Ice Glaciers
Icebergs○ Large pieces of ice
that break off and drift into the ocean
○ Mostly under water○ Calving
Process of production
12-3 Erosion and Deposition by Ice Glaciers
Movement○ Ice that builds up will
move downhill○ Thickness of ice and
steepness of slope will determine how fast it moves
12-3 Erosion and Deposition by Ice Glaciers
Crevasses○ A large crack that
forms where the glacier picks up speed or flows over a high point
○ Ice cannot stretch quickly and cracks
12-3 Erosion and Deposition by Ice