EARTH AND LIFE SCIENCE EROSION AND DEPOSITION

FOCUSES ON EROSION AND DEPOSITION BASIC CONCEPT

1. Graphic organizer

2. Using a bubble graphic organizer, write down what have you remember from previous lesson. WEATHERING

3. Tray with sand think of as many ways as you can to move the sand from one end of the tray to the other blowing, tilting the tray, running water, pushing,

4. Erosion and Deposition Prepared by: Diane G uilaran Special Science teacher I

5. WEATHERING VS EROSION

6. WEATHERING VS EROSION

7. TASK: List all the italicized word from the next succeeding slides Identify the meaning of the word Search of example pictures

8. Weathering occurs in situ, that is, particles stay put and no movement is involved. As soon as the weathering product starts moving (due to fluid flow) we call the process erosion.

9. Weathering , erosion/transportation, and deposition are exogenic processes that act in concert, but in differing relative degrees, to bring about changes in the configuration of the Earth’s surface.

10. EROSION The removal of weathered rock and soil from its original location remove material through a number of different agents, including running water, glaciers, wind, ocean currents, and waves

11. Deposition These agents of erosion can carry rock and soil thousands of kilometers away from their source. After the materials are transported, they are dropped in another location

12. AGENTS OF EROSION

13. Running water Moving water is perhaps the most powerful agent of erosion . Stream erosion can reshape entire landscapes. Water flowing down steep slopes has additional erosive potential resulting from gravity, causing it to cut downward into the slopes , carving steep valleys and carrying away rock and soil . encompasses both overland flow and stream flow

14. Task: In your ½ crosswise yellow pad Differentiate overland flow and streamflow.

15. F actors that affect stream erosion and deposition Velocity – dictates the ability of stream to erode and transport; controlled by gradient, channel size and shape, channel roughness, and the amount of water flowing in the channel

16. F actors that affect stream erosion and deposition Discharge – volume of water passing through a cross-section of a stream during a given time ; as the discharge increases, the width of the channel, the depth of flow, or flow velocity increase individually or simultaneously

17. Styles of erosion Vertical erosion (down cutting), Lateral erosion head ward erosion

18. Streamflow erosion occurs through: Hydraulic action Abrasion S olution

19. Streams transport their sediment load in three ways: solution (dissolved load) suspension (suspended load ), sliding and rolling along the bottom (bed load)

20. A stream’s ability to transport solid particles is described by: competence (size of the largest particle that can be transported by the stream) capacity (maximum load a stream can transport under given conditions)

21. Deposition occurs when a river loses its capacity to transport sediments. With decrease in velocity and competence , sediments start to settle out. River deposits are sorted by particle size.

22. Ocean or sea waves wind generated waves, tsunami, tides, seiches waves erode and move sediment along the shore: Shoreline erosion processes Hydraulic action, abrasion, corrosion Transport by waves and currents: Longshore current, beach drift

23. Glaciers moving body of ice on land that moves downslope or outward from an area of accumulation (Monroe et. al., 2007)

24. Types of glaciers : i . Valley (alpine) glaciers — bounded by valleys and tend to be long and narrow ii. Ice sheets (continental glaciers) — cover large areas of the land surface; unconfined by topography . Modern ice sheets cover Antarctica and Greenland iii. Ice shelves — sheets of ice floating on water and attached to the land. They usually occupy coastal embayments

25. Ice cannot erode the bedrock on its own. Glaciers pick up rock fragments and use them to abrade the surfaces over which they pass . Processes responsible for glacial erosion: Plucking (lifting pieces of bedrock beneath the glacier ) and abrasion (grinding and scraping by sediments already in the ice). Abrasion yields glacial polish and glacial striations

26. Wind i . Wind erodes by: deflation (removal of loose, fine particles from the surface), and abrasion (grinding action and sandblasting )

27. Wind ii . Deflation results in features such as blowout and desert pavement. Abrasion yields ventifacts and yardangs .

28. Wind iii . Wind, just like flowing water, can carry sediments such as: ( 1) bed load (consists of sand hopping and bouncing through the process of saltation), and (2) suspended load (clay and silt-sized particles held aloft).

29. Groundwater The main erosional process associated with groundwater is solution. Slow-moving groundwater cannot erode rocks by mechanical processes, as a stream does, but it can dissolve rocks and carry these off in solution.

30. Groundwater This process is particularly effective in areas underlain by soluble rocks, such as limestone, which readily undergoes solution in the presence of acidic water.

31. K arst topography and its associated landforms distinctive type of landscape which develops as a consequence of subsurface solution. It consists of an assemblage of landforms that is most common in carbonate rocks, but also associated with soluble evaporate deposits.

32. Associated land form in Karst Topography (1) Cave/Cavern – forms when circulating groundwater at or below the water table dissolves carbonate rock along interconnected fractures and bedding planes .

33. Associated land form in Karst Topography (2) Sinkholes ( Dolines ) – circular depressions which form through dissolution of underlying soluble rocks or the collapse of a cave’s roof

34. Associated land form in Karst Topography (3) Tower karst – tall, steep-sided hills created in highly eroded karst regions.

35. Gravity Mass wasting — the downslope movement of soil, rock, and regolith under the direct influence of gravity i . As the slope angle increases, the tendency to slide down the slope becomes greater. ii. Role of water: adds weight to the slope, has the ability to change angle of repose, reduces friction on a sliding surface , and water pore pressure reduces shear strength of materials

36. Activity: Annotated sketch of areas of erosion and deposition Using google map locate a river or coastline nearest their community. Identify locations of erosion and deposition by making an annotated sketch of the river or coast. Explain how the different erosional and depositional features may have formed. Predict how the river/coast may change shape in the future, and identify areas susceptible to fluvial/coastal erosion

37. Rubrics 5 4 3 2

38. formulate three review questions that cover the content of the lesson. ½ crosswise yellow pad