Stream Development

1. Stream Development

5. 100 Aker Wood http://www.geocities.com/Hollywood/Hills/2255/pigmap.gif

6. By the time it came to the edge of the Forest the stream had grown up, so that it was almost a river, and, being grown-up, it did not run and jump and sparkle along as it used to do when it was younger, but moved more slowly. For it knew now where it was going, and it said to itself, "There is no hurry. We shall get there some day." http://www.lavasurfer.com/wtp/pooh-100akermap.html

7. But all the little streams higher up in the Forest went this way and that, quickly, eagerly, having so much to find out before it was too late.

8. Stages of Stream Development http://dynamic.ou.edu/notes/running_water/running_water.html

9. Young Streams: -steep slope/gradient -high velocity -down cutting erosion http://pinker.wjh.harvard.edu/photos/american_west/pages/Yosemite%20Falls.htm

10. Narrow and V-Shaped Valley http://dynamic.ou.edu/notes/running_water/v-shaped_valley_ecuador.jpg

11. Rapids

12. More Mature… Letchworth Gorge- Genesee River

13. Mature Streams • flood plain develops • lower slope/gradient • meanders (bends) form http://dynamic.ou.edu/notes/running_water/running_water.html

14. Meanders of the Keve River, Angola as it crosses its broad flood plain. http://www.birdingafrica.com/africa_tours/images/ang_kevefloodplain.jpg

15. Deep water on outside of meander curve • http://dynamic.ou.edu/notes/running_water/deep_water,outsideofmeander,rcky_mt_np_co.jpg

16. Old Age Streams http://www.cox-internet.com/coop/deltawebpage.html

17. Erosion and Deposition along a meander http://dynamic.ou.edu/notes/running_water/erosion,dep,meander_western_wy.jpg

18. OLD Streams -low slope/gradient -very wide channel and floodplain -abundant meanders NIAGARA RIVER

19. http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/fluvial/meander_GSC_small.jpghttp://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/fluvial/meander_GSC_small.jpg

20. http://gpc.edu/~pgore/myphotos/appalach/meander2.jpg

21. http://dynamic.ou.edu/notes/running_water/low-gradient_stream_katmai_ak.jpghttp://dynamic.ou.edu/notes/running_water/low-gradient_stream_katmai_ak.jpg

22. Oxbow Lakes Form http://dynamic.ou.edu/notes/running_water/oxbow2.jpg

23. http://www.csus.edu/indiv/s/slaymaker/Archives/Geol10L/meanders1.jpghttp://www.csus.edu/indiv/s/slaymaker/Archives/Geol10L/meanders1.jpg

24. Point bar http://images.google.com/imgres?imgurl=http://www.csus.edu/indiv/s/slaymaker/Archives/Geol10L/meanders1.jpg&imgrefurl=http://www.csus.edu/indiv/s/slaymaker/Archives/Geol10L/landforms.htm&h=361&w=418&sz=221&hl=en&start=19&tbnid=vDkP6x64wC9uRM:&tbnh=108&tbnw=125&prev=/images%3Fq%3Dmeander%2Bstream%26svnum%3D10%26hl%3Den%26sa%3DG

27. http://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swfhttp://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swf

29. http://geobytesgcse.blogspot.com/2006/11/middle-course-of-river-meanders-ox-bow.htmlhttp://geobytesgcse.blogspot.com/2006/11/middle-course-of-river-meanders-ox-bow.html

30. DO NOW: Factors that cause deposition • If velocity of a stream or river decreases, what will happen to the sediment that the stream or river is carrying? • What happened to the kinetic energy?

31. Is sediment of mixed sizes sorted by streams as kinetic energy decreases and velocity slows?

32. Deposition • the process of dropping material as kinetic energy of an erosional agent decreases

33. Factors causing deposition • Deposition occurs when the velocity of speed of an erosional agent decreases • Two Factors • The velocity of the erosional system • The characteristics of the sediments

34. Velocity of an Erosional System and the rate of deposition • As velocity decreases, particles are deposited in order of their size • In a fast stream all particles will be suspended…as it slows down the particles will be deposited in order (from large to small)

35. Characteristics of Sediment and the rate of deposition • Size- the larger the sediment the faster the rate of deposition • Shape- the mope spherical the sediment the faster the rate of deposition • Density- the greater the density the faster the rate of depostion

36. Delta- fan shaped deposit of sediments at the mouth of a river

37. DO NOW 1. The block diagram below shows a displacement of rock layers.Which process describes the downward sliding of the rock material? A) tidal changes B) glacial erosion C) mass movement D) lava flow  2. Create a graph that demonstrates the relationship between the distance from a river delta into the ocean and the average size of sediments deposited on the ocean floor. Try to describe the relationship.

39. Deposition • the process of dropping material as kinetic energy of an erosional agent decreases Stream Deposition Occurs In Areas: 1. at widening rivers 2. on the inside of a curve of a meandering stream 3. at the mouth of stream/river that flows into a larger body of water As kinetic energy ______________, water velocity _____________.

40. Horizontal Sorting • Horizontal sorting- As water slows gradually, smaller and smaller particles drop out causing • Gradual decrease in velocity Sorting Animation McDougal Sorting Animation

42. Vertical Sorting • Occurs when water velocity decreases suddenly • Examples: -Flash flooding -Spring thaw -frozen ground does not allow for snow melt or rain water to penetrate soil which leads to increased runoff into streams/rivers

43. Graded Bedding • From repeated sorting events • Ex. Annual (yearly) spring thaws • Seasonal melting of glaciers

44. Graded Bedding

45. Wind- Crossbedding

46. GLACIER- Graded bedding in a glacial esker. Medina NY July 2004

47. Glacial TILL- UNSORTED

48. Normal Wave conditions- cross bedding

49. Hurricane waves and tsunami Waves- graded bedding

50. Billy Hill A Velocity = 150 cm/s Sizes carried: Sizes deposited: Lake Floyd B Velocity = 50 cm/s Sizes carried: Sizes deposited: C Velocity = 10 cm/s Sizes carried: Sizes deposited: DO NOW: • Please take out Deposition in Streams Questions