1. 3. Wind Erosion

2. Common in Dry Climates (deserts) and along shorelines

3. Dunes Dunes – gentle slopes faces the wind
Wind only pick up and carry clay, silt and sand

4. WIND

5. Wind Erosion
Sand blasted rock
pitted

6. Sand Blasted and Pitted Rock
Sand can only be picked up, up to 3 feet so lower parts get eroded away
also get pitted rocks

9. Cross bedded deposits

11. deposits from ripples and dunes
indicate that the depositional environment was either water or wind

12. 4. WAVES

14. Sand Mainly comes from rivers and streams
Sand is suspended in the water and gets bounced around
Round sediments  abrasion
Wave action, wind and currents move sand up and down the coast

15. Waves
Winds affect direction, velocity and size of wave

16. Longshore Current/drift
Movement of sediment parallel to the shore as waves strike shoreline at an angle
Waves hit at an angle, water washes back

18. Longshore current Movement of sand is toward east
Movement of sand is toward west

19. Erosion/deposition
Longshore current
Deposition
Erosion

20. Barrier Island Long offshore deposit of sand parallel to coast
Longshore drift – deposits, removes, and re-deposits sand so barrier islands are constantly changing

21. Barrier Island

23. Mass Movement

24. Mass Movements
The downslope movement of large masses of earth materials due to _______
gravity

25. Three Main Types
Creep
Landslides
Mudflows

26. Creep Gradual downhill movement of soil Slow process
Evidence: (tilted fences, utility pole, bent trees)

28. Landslides Sudden and rapid downhill movement
Likely to occur on steep slopes
Caused by high precipitation which “lubricates” sediment (deceases friction)

29. Slump
La Conchita, CA
Spring 1995

30. Rockslide Porteau Cove, B.C July 30, 2008

31. Tully Landslide
April 27, 1993

32. Mudflow
Cause - Fine-grained sediment becomes saturated with water and begins to flow
Likely to occur on steep slopes
Fast and destructive

33. Mt. Saint Helen’s, WA, Lahar March 21, 1982