GEOLOGY CMU Bill Palmer

1. GEOLOGYCMUBill Palmer Lecture 14 Streams and Rivers

2. GEOLOGY • Johnstown Flood-A famous flood! • Johnstown, Pennsylvania • Recreational area for Pittsburgh • Mud and gravel dam across the Conemaugh River • May 31, 1889-Torrential rain • Dam collapses • 60foot tall wall of water slammed into Johnstown • 2,300 people dead

3. GEOLOGY • Jamestown PA focus of national sympathy • Years to recover-first Red Cross relief program • Flood-an event when volume of water in a stream or river becomes so great that water covers areas outside the normal limits of the stream • Rivers > streams • Earth is only planet with streams of running water

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5. GEOLOGY • Falling water may rush off the land in sheets-Sheetwash

6. GEOLOGY • Types of Drainage Patterns: • Dendritic-Tree branches (Ozarks) • Radial-Flow out like spokes of a wheel (St. Francois Mtns.) • Rectangular-form at right angles • Trellis- like a garden trellis (N. Missouri)

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8. GEOLOGY • Watershed-the entire area drained by a river or stream system • Divide-The high area or ridge that separates one drainage area from another

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10. GEOLOGY • Permanent Streams-Streams that contain water year round • Ephemeral Streams-Streams that contain water only after a heavy rain (dry wash, arroyo, or wadi)

11. GEOLOGY • Discharge-The volume of water a stream discharges in a given period Amazon discharges 200,00 cubic meters/second this is 15% of all runoff of the earth’s total Mississippi River = 17,000 cubic meters/second

12. GEOLOGY • Amazon River Delta

13. GEOLOGY Mississippi River Delta

14. GEOLOGY • Discharge is difficult-Depends on cross-section of stream, head pressure, and friction of stream bed

15. GEOLOGY • Running water causes four types of Erosion: • Scouring-removal of loose fragments • Breaking and lifting-Moving water lifts sediments • Abrasion-Sand and silt water is like a sandblaster and abraids channels • Dissolution-Water dissolves minerals chemically

16. GEOLOGY • Sediment Load-three types • Dissolved load-Chemically dissolved soluble minerals • Suspended load-Tiny grains of material that swirl along with water • Bed load-The big chunkers that move along the bottom (the faster the stream the bigger the chunkers)

17. GEOLOGY • Deposition- When a stream dumps its sediment load=Deposition • Alluvium-sediments transported by a stream Alluvium-Copper River, Alaska

18. GEOLOGY • Stream Characteristics- • Valleys-The V-shaped canyon created by a down-cutting river (Colorado) • The same type of rock creates a V-shape • Hard and soft rock create a stair-step pattern • Rapids-when river flows over boulders or other obstructions • Waterfalls-when rivers free-fall down the stream-bed

19. GEOLOGY • Stream Characteristics-Streams are classified as young, mature, or old age. • Young-Mountain Stream • Mature-Cedar Creek • Old age-Missouri and Mississippi

20. GEOLOGY • Stream Characteristics- • Old Streams have meanders, oxbow lakes, and few waterfalls. Wide valleys with flood plain (MO and MS rivers) • Young streams are straight, flow fast, rapids and waterfalls, and narrow V-shaped valleys • Mature streams are in the middle

21. GEOLOGY Youthful Youthful Mature Old Age Old Age

22. GEOLOGY Youthful-waterfalls and narrow canyons Old age-Meanders and oxbow lakes

23. GEOLOGY What are these?

24. GEOLOGY • Alluvial Fan-When a relative fast moving stream or river emerges into a slow moving body of water and drops its sediment load.

25. GEOLOGY • Braided Stream-when a stream weaves back and forth creating a braided look.

26. GEOLOGY • Meanders-when a river snakes back and forth, usually a sign of an old age river.

27. GEOLOGY • Delta-where running water enters a slow or stationary body of water and dumps its sediments load

28. GEOLOGY Nile R. Delta Yangtze R. Delta Mekong R. Delta

29. GEOLOGY • Stream piracy-When erosion of one stream captures the water of another stream

30. GEOLOGY • Rejuvenation-When a stream that has meandering traits is uplifted and given increased down cutting strength. Most of Missouri’s Ozark rivers and streams have this characteristic. Current River

31. GEOLOGY • Floods-Two Types • Seasonal Floods-Gradually submerge a floodplain; usually during rainy season; last for days or weeks (Missouri River floods of 1993 and 1995) • Flash Floods-Happen very quickly; people can’t escape; more of a problem in narrow canyons or deserts; (flash floods of Big Thompson River Canyon [1976] and Jamestown flood)

32. GEOLOGY Seasonal Flood Flash Flood

33. GEOLOGY • Problems of Rivers in America • Pollution-Cuyahoga River caught on fire; can’t eat fish from MO River due to Chlordane (termite poison) • Dam Construction-5,000 dams over 15 m high; sometimes flood more land than they protect • Overuse of water-Colorado River never reaches ocean • 65%=agriculture • 25%=industry • 5%=human drinking • 5%=evaporation loss • 0%=water that reaches ocean

34. GEOLOGY Cuyahoga River catches on fire

35. GEOLOGY Chlordane catfish from MO river

36. GEOLOGY Truman Dam Hoover Dam Bagnell Dam and Spoonbill Catfish

37. GEOLOGY Water from the Colorado River is “used up” before it reaches the Gulf of Baja.

38. GEOLOGY-Wrap-Ups • 1. What and when was the Johnstown flood? • 2. Sketch and label four types of drainage patterns. • 3. What is a watersheds? • 4. What are ephemeral streams? • 5. What are four types of erosion from streams?

39. GEOLOGY-Wrap-Ups • 6. What is the difference between rapids and waterfalls? • 7. What is a rejuvenated stream? • 8. What type of floods do we have on the Missouri River? • 9. List three general problems with rivers and streams in USA. • 10. What is your favorite stream or river in MO?