Upload
shae
View
38
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Chapter 12. Agents of erosion and deposition. 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. - PowerPoint PPT Presentation
Citation preview
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