Unit 4 surface processes and landscapes

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Unit 4 surface processes and landscapes

  1. 1. 3:00
  2. 2. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  3. 3. Types of Weathering Physical –causes a rock to crack or break into pieces without changing it chemically
  4. 4. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  5. 5. Physical Weathering <ul><li>Abrasion </li></ul><ul><li>sediments carried by streams and wind blown sand cause particles to collide into each other and the surrounding rock. </li></ul>
  6. 6. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Bump & Grind (streams/wind) smooth rounded particles Frost Wedging – Plants – Exfoliation - Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  7. 7. Physical Weathering <ul><li>Frost wedging </li></ul><ul><ul><li>water seeps into the cracks in a rock and freezes causing the ice to expand . </li></ul></ul>
  8. 9. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Bump & Grind (streams/wind) Smooth, rounded particles Frost Wedging – water seeps into the cracks in a rock and freezes causing the ice to expand Plants – Exfoliation - Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  9. 10. Physical Weathering <ul><li>Plants </li></ul><ul><li>Trees and shrubs can grow through cracks in rocks. </li></ul><ul><li>Their roots wedge into crevices. </li></ul>
  10. 11. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Bump & Grind (streams/wind) Frost Wedging – water seeps into the cracks in a rock and freezes causing the ice to expand Plants – roots wedge into rock and grow (expand) Exfoliation - Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  11. 12. Physical Weathering <ul><li>Exfoliation –cycle of heating and cooling causes the rock to expand & contract so it breaks off in slabs or layers. </li></ul>
  12. 14. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Bump & Grind (streams/wind) Frost Wedging – water seeps into the cracks in a rock and freezes causing the ice to expand Plants – roots wedge into rock and grow (expand) Exfoliation – Freeze & Thaw causes rock to “peel” Chemical – Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  13. 15. <ul><li>Chemical – Any process that causes rocks to breakdown by chemical action and results in a change in the minerals (chemical composition). </li></ul>Types of Weathering
  14. 16. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – involves water + it changes the rocks chemical composition Carbonation – Oxidation – Hydration – Plant Acids – Acid Rain - =
  15. 17. Chemical Weathering <ul><li>Carbonation – carbon dioxide in the atmosphere dissolves in the droplets of water that make-up clouds. This forms a weak carbonic acid. Carbonic acid reacts with certain rocks and minerals which include: calcite, limestone, marble and chalk. </li></ul>
  16. 18. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – involves water + it changes the rocks chemical composition Carbonation – CO 2 + H 2 O form weak acid that dissolves limestone Oxidation – Hydration – Plant Acids – Acid Rain - =
  17. 19. Chemical Weathering <ul><li>Oxidation - Water + Oxygen = Rust </li></ul>
  18. 20. Chemical Weathering <ul><li>Hydration </li></ul>
  19. 21. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – involves water + it changes the rocks chemical composition Carbonation – CO 2 + H 2 O form weak acid that dissolves limestone Oxidation – Rust Hydration – Water dissolves mineral to clay Plant Acids – Acid Rain - =
  20. 22. Chemical Weathering <ul><li>Plant Acids – Plants produce weak acids that dissolve minerals in a rock, weakening the rock. </li></ul>
  21. 23. Chemical Weathering <ul><li>Acid Rain – Gases produced by humans can dissolve in the water droplets of a cloud to produce acid rain . </li></ul><ul><ul><li>These acids include: H2SO4 – sulfuric acid </li></ul></ul><ul><ul><li>HNO3 – nitric acid </li></ul></ul>
  22. 24. Weathering the breaking of rock into smaller particles called sediment . Physical ( AKA – Mechanical ) – causes a rock to crack or break into pieces without changing it chemically Abrasion – Frost Wedging – Plants – Exfoliation - Chemical – involves water + it changes the rocks chemical composition Carbonation – CO 2 + H 2 O form weak acid that dissolves limestone Oxidation – Rust Hydration – Water dissolves mineral to clay Plant Acids – plants produce weak acid that dissolves rocks. Acid Rain – man-made! =
  23. 25. Physical Chemical Caves/Karst Clay Dissolved minerals (hard water) Abrasion – smooth & rounded The WEDGE Exfoliation Climate Rock Type Exposure Particle Size Time Key Vocabulary Concept Map Results in: Sediments (ESRT pg 6) Dissolved Minerals Soil (pg 6 & 7 ) Erosion (pg 8 ) Weathering 4 things that help: My Definition of Weathering Water
  24. 26. Rates of Weathering FAST SLOW Climate Temp & Moisture Cold/Warm & Dry Warm & Wet Rock Type Igneous & Metamorphic Sedimentary Shale/siltstone – conglomerate - limestone Sandstone Dolostone
  25. 27. Rates of Weathering Climate is the major factor that affects the rate of weathering
  26. 28. Rates of Weathering Due to climate and different weathering processes, landscapes develop differently. Arid Climate – angular, sharp edges, little vegetation
  27. 29. Rates of Weathering Humid Climate – soft, rounded with vegetation
  28. 30. Rock Types – cause softer, less resistant rocks to wear away , leaving harder, more resistant rocks behind. Limestone (A) is most resistant Shale (B) is least resistant Rates of Weathering
  29. 31. Rates of Weathering Carpenter Falls shows differential weathering.
  30. 32. Rates of Weathering Niagara Falls
  31. 33. Rates of Weathering FAST SLOW Exposure And TIME Underground/lesstime Above Ground Particle Size Or Surface Area Large size or less surface area Small size or more surface area
  32. 34. Rates of Weathering Particle Size – As a rock breaks into smaller pieces, the surface area increases, and therefore the rate of weathering increases .
  33. 35. Products of Weathering Solid Sediments <ul><li>Colloids </li></ul><ul><li>very small solid particles, too small to be seen with an ordinary microscope, and too light to settle in water. </li></ul><ul><li>Even in calm water, they remain suspended within the water. </li></ul>Size by name and number is in ESRT pg 6
  34. 36. Products of Weathering <ul><li>In western New York that may mean calcium and lime deposits on your shower or if you have a well, sulfur and rust stains in the sink. </li></ul>Dissolved Minerals – cause the “hardness” in groundwater (and surface water).
  35. 37. Chemical Weathering <ul><li>Carbonation – carbon dioxide in the atmosphere dissolves in the droplets of water that make-up clouds. This forms a weak carbonic acid. Carbonic acid reacts with certain rocks and minerals which include: calcite, limestone, marble and chalk. </li></ul>
  36. 38. Carlsbad Cavern, New Mexico
  37. 39. Sinkhole - Florida
  38. 41. Formation of Caverns – pg 5 in notes Label your diagram and explain how caves form in limestone! Use a textbook – pg 310 - 311
  39. 42. Products of Weathering - Soil <ul><li>Read pg 7 and complete the “Etch-a-Sketch” on pg 6 of the notes </li></ul><ul><ul><li>You may need to use a text book for picture ideas. </li></ul></ul>
  40. 43. Residual Vs. Transported <ul><li>If the soil does not match the parent rock is transported </li></ul><ul><li>if the sediments match the parent rock the soil is residual . </li></ul><ul><li>NYS has mostly transported sediments because of glaciation! </li></ul>Slide 49
  41. 44. Ahead to 6:25
  42. 45. Definition : - Transporting or moving weathered sediments Driving Force: GRAVITY <ul><li>GLACIERS </li></ul><ul><li>Unsorted & loose </li></ul><ul><li>Scratched </li></ul><ul><ul><li>Polished </li></ul></ul><ul><ul><li>U- shape valleys </li></ul></ul><ul><li>WATER </li></ul><ul><li>#1 agent </li></ul><ul><li>Well sorted </li></ul><ul><li>Smooth </li></ul><ul><li>Rounded </li></ul><ul><li>GRAVITY </li></ul><ul><li>Unsorted </li></ul><ul><li>Mass wasting </li></ul><ul><li>Creep </li></ul><ul><li>Slump </li></ul><ul><li>Talus </li></ul><ul><li>Humans </li></ul><ul><li>Farming </li></ul><ul><li>Mining </li></ul><ul><li>Deforestation </li></ul>Transported Sediment = Click here Residual Sediment = <ul><li>WAVES </li></ul><ul><li>Beaches </li></ul><ul><li>Longshore current </li></ul><ul><li>Jetties & Groins </li></ul><ul><li>WIND </li></ul><ul><li>Arid Deserts </li></ul><ul><li>Dunes </li></ul><ul><li>Pitted/frosted </li></ul>Erosion
  43. 46. Erosion by Gravity MUDSLIDE
  44. 47. Erosion by Gravity Slump Talus Slope
  45. 48. Erosion by wind
  46. 49. Deposition Factors affecting Deposition : SIZE Velocity Shape Gradient Density Discharge <ul><li>Water Deposits </li></ul><ul><li>Well Sorted </li></ul><ul><li>Rounded </li></ul><ul><ul><li>Smooth </li></ul></ul><ul><ul><li>Abrasion </li></ul></ul>Vertical Sorting - Horizontal Sorting The settling or dropping of particles after being picked up by an agent of erosion
  47. 50. Wind Deposits <ul><li>Similar to water </li></ul><ul><li>Loss of velocity will result in deposition by size </li></ul><ul><li>Well sorted </li></ul><ul><li>Graded bedding </li></ul>Velocity = FAST - Erosion Velocity = Slow - Deposition Skip to 60
  48. 51. Deposition <ul><li>Size – As the size of sediment increases , the rate of deposition increases . </li></ul>Page 6 ESRT
  49. 52. Deposition <ul><li>Density – As the density of sediment increases , the rate of deposition increases . </li></ul><ul><li>Shape – The flatter the particle the slower the deposition. </li></ul>
  50. 53. <ul><li>As Velocity goes up – Erosion goes up and Deposition goes down </li></ul><ul><li>As Gradient gets steeper – Erosion goes up and Deposition goes down </li></ul><ul><li>As Discharge increases – Erosion goes up . </li></ul>Deposition
  51. 54. Deposition Particle Size vs. Stream Velocity Page 6 of ESRT
  52. 55. Deposition <ul><li>When a stream enters a body of water, its speed will decrease , and therefore the deposition of sediments occurs. </li></ul><ul><ul><ul><li>A deposit at the mouth of a stream where it enters a large body of water is called a delta . </li></ul></ul></ul>
  53. 56. The Mississippi Delta
  54. 57. Deposition A delta is an example of the horizontal deposition of sediments in the water. Clay Boulders Cobbles Pebbles Evidence of Sorted Sediment
  55. 58. Deposition
  56. 59. Deposition Factors affecting Deposition: SIZE Velocity Shape Gradient Density Discharge Water Deposits Well sorted, round, smooth, graded bedding Vertical Sorting – mixed particles in order of big, medium, small due to changes in velocity Horizontal Sorting – Occurs when a stream enters a large body of water &loses velocity The settling or dropping of particles after being picked up by an agent of erosion Back to 50
  57. 60. Erosional/Depostional Systems RIVERS YOUNG OLD MATURE V shaped valley Fast Steep Straight Rapids & Waterfalls Medium slope Slight curves Medium speed Narrow floodplain Small rapids Flat Slow Lots of meanders Straight Wide floodplain & Channel
  58. 61. Erosional/Depositional Systems - Rivers
  59. 62. The bends in a stream’s channel are called meanders Erosional/Depositional Systems - Rivers
  60. 63. Erosional/Depositional Systems - Rivers Arial Map View of a stream Channel
  61. 64. Erosional/Depositional Systems - Rivers At the outside of the curve, the stream velocity increases , therefore erosion occurs. At the inside of the curve, the stream velocity decreases , therefore deposition occurs.
  62. 65. Erosional/Depositional Systems - Rivers Deposition Erosion
  63. 66. Erosional/Depositional Systems - Rivers Formation of Oxbow Lake – the work of erosion and deposition Oxbow Formation Part 1 Part 2 – Why?
  64. 68. Erosional/Depositional Systems - Glaciers <ul><li>Glaciers can really move a lot of material , dramatically changing the surface of the earth. </li></ul><ul><li>2 Types: </li></ul><ul><li>Continental – covered NYS over 10,000 years ago and is the cause of our “till” deposits, finger lakes and transported soils! </li></ul><ul><li>Alpine – in mountains </li></ul><ul><ul><li>Create U-Shaped valleys </li></ul></ul>
  65. 69. Erosional/Depositional Systems - Glaciers
  66. 70. Erosional/Depositional Systems - Glaciers Continental Glacier GLACIERS Features: Alpine Glacier Unsorted, loose deposits Ground up rock flour or glacial till Moraines U-shape Valleys Kettle lakes, drumlins, outwash plains Erratics – large boulders that don’t match the natural bedrock Moved from the north (pole) to the south Move downhill!
  67. 71. Erosional/Depositional Systems - Glaciers <ul><li>Glacial Features </li></ul><ul><li>Terminal Moraine </li></ul><ul><li>Lateral Moraine </li></ul><ul><li>Glacial stream </li></ul><ul><li>Outwash plains </li></ul><ul><li>Braided streams </li></ul><ul><li>U- Shaped Valleys </li></ul>
  68. 72. Erosional/Depositional Systems - Glaciers During Glaciation Post - Glaciation Holy Goodness – it’s a U shape valley!
  69. 73. The Work of Waves The most important agent shaping coastal landforms is wave action. And WHY do you need to know this? – because Long Island is in NYS!
  70. 74. <ul><li>As wind moves over the ocean, it produces waves and currents that erode the bordering land. </li></ul><ul><li>Waves can also be produced by underwater earthquakes and the effect of the moon in producing tides. </li></ul>
  71. 75. <ul><li>The height of a wind created wave depends on the length of time the wind blows and the Fetch. </li></ul><ul><li>Fetch is the length of open water over which the wind blows. </li></ul><ul><li>Normal winds rarely produce ocean waves higher than 15m. </li></ul>
  72. 76. <ul><li>Each particle moves in place in a circular motion. </li></ul><ul><li>This motion occurs below the surface as well, in smaller and smaller circles. </li></ul>
  73. 77. SURF <ul><li>When waves enter shallow water near the shore, they drag against the bottom. </li></ul><ul><li>The waves then become unstable and water rushes toward the shore as breaking waves or surf. </li></ul>
  74. 78. <ul><li>Wave movement toward the shore often builds up a strip of sediment at the coastline called a beach. </li></ul><ul><li>Beaches are composed of whatever sediment is available, but most beaches are composed of sand. </li></ul>
  75. 79. <ul><li>Waves moving at an angle to the shoreline push water along the shore creating a longshore current. </li></ul><ul><li>A longshore current is a movement of water parallel to and near the shoreline. </li></ul><ul><li>Longshore currents transport sand in a direction parallel to the shoreline. </li></ul>
  76. 80. <ul><li>Sand moving along a relatively straight shore keeps moving until the shoreline changes direction. </li></ul><ul><li>This happens at bays and headlands. </li></ul><ul><li>Here the longshore current slows and sand is deposited at the near end of the headland. </li></ul><ul><li>A long narrow deposit of sand connected at one end to the shore is called a spit. </li></ul>
  77. 81. SPIT
  78. 82. Long Point, Lake Erie, Canada Long Shore Current
  79. 83. Rip Currents
  80. 84. Oregon Inlet – Nags Head, NC
  81. 85. <ul><li>During storms waves can be much more powerful than normal. </li></ul>
  82. 86. During these times the beach tends to erode more and the sand is carried back into the ocean. There it is usually deposited as underwater bars parallel to the shore.
  83. 87. If these sand bars rise above the average sea level winds will help to pile up sediment. When vegetation begins to grow and stabilize the offshore sediment pile, a barrier island is created.
  84. 88. Outer Banks, NC – Barrier Islands
  85. 89. Hatteras – Ocracoke Island, NC Pamlico Sound (Land Side) Atlantic Ocean – Sea Side Barrier Island
  86. 90. Man-Made structures – Help or Hindrance? <ul><li>Groins and jetties are built perpendicular to the shoreline.  </li></ul><ul><li>Groins extend like fingers away from the shore. </li></ul><ul><li>Jetties are built where a river empties into ocean. </li></ul>
  87. 91. The Problem????
  88. 92. Landscape Development <ul><li>How is the Earth’s surface shaped by weathering, erosion and deposition? </li></ul>
  89. 93. Landscape Development <ul><li>Landscape : A region on the Earth’s surface in which physical features, such as hills, valleys, and streams are related by a common origin (it simply means “scenery”) </li></ul><ul><li>Three (3) main types: Mountains, Plains and Plateaus </li></ul>
  90. 94. Landscape Development <ul><li>Mountains </li></ul><ul><li>Greatest relief between their peaks and valleys </li></ul><ul><li>Created by tectonic forces (igneous and metamorphic rocks) </li></ul>
  91. 95. Landscape Development <ul><li>Mountains </li></ul><ul><li>Steep mountain slopes have fast erosive streams acting on them, creating deep valleys and waterfalls </li></ul>
  92. 96. Landscape Region MOUNTAINS: Elevation: HIGH Slope: STEEP Common Rock Type: IGNEOUS/Metamorphic Unique Features: Rapids/waterfalls, steep gorges
  93. 97. Landscape Development <ul><li>Plateaus </li></ul><ul><li>Low relief (flat) </li></ul><ul><li>High elevation </li></ul><ul><li>Horizontal rock formations </li></ul>
  94. 98. Landscape Development <ul><li>Plateaus </li></ul><ul><li>Streams can cut steep valleys into plateaus and dissect them </li></ul><ul><li>Ex: Grand Canyon </li></ul><ul><ul><li>Catskills, NY </li></ul></ul>
  95. 99. Landscape Development <ul><li>And our own Grand Canyon of the East </li></ul><ul><li>Letchworth State Park </li></ul><ul><li>Located on the Allegheny Plateau of New York State </li></ul>
  96. 100. Landscape Region PLATEAU: Elevation: Slope: Common Unique Rock Type: Features: HIGH Elevation Flat Sedimentary Canyons LOW relief
  97. 101. Landscape Development <ul><li>Plains (lowlands) </li></ul><ul><li>Have the least relief </li></ul><ul><li>Generally flat and low elevations </li></ul><ul><li>Underlain by flat layers of sedimentary rock </li></ul>
  98. 102. Landscape Region LOWLANDS (PLAINS): Elevation: LOW Slope: FLAT Common Rock Type: Sedimentary Unique Features: Found along lakes/shorelines and rivers
  99. 103. Humans Tectonic Forces Climate Time Crustal Materials Humid LANDSCAPE DEVELOPMENT ARID 97
  100. 104. Tectonics Tectonic activity is an “earth-building” activity
  101. 105. Folding and Faulting
  102. 106. Folding and Faulting Folding is the process that bends and twists rocks, usually due to compression  Faulting is the process where rocks move past each other along a fracture 82
  103. 107. Landscape Development The Niagara escarpment is the exposed edge of a large scale syncline (geosyncline). = Limestone and Dolostone
  104. 108. Landscape Development In Ontario, the Niagara Escarpment has been formed by differential erosion. = Limestone Hard!
  105. 109. Landscape Development Where rivers cross the escarpment, waterfalls may be formed by undercutting .
  106. 110. Some QUITE Spectacular!
  107. 111. Landscape Development <ul><li>Due to different rock types in the same area, the harder rock (competent) will form hills and ridges </li></ul><ul><li>Erosion of the weaker rock (incompetent) will make major valleys </li></ul><ul><li>Streams tend to follow areas of weaker rock </li></ul>
  108. 112. Landscape Development <ul><li>How does landscape affect stream drainage patterns? </li></ul><ul><li>Landscape determines how a river will flow and what it will erode! </li></ul>
  109. 113. Landscape Development <ul><li>Stream Drainage Patterns </li></ul>
  110. 114. Landscape Development <ul><li>CLIMATE is most influential in determining the rate of landscape development. </li></ul>
  111. 115. Arid Climate <ul><li>Less water erosion </li></ul><ul><li>More steep and angular slopes. </li></ul><ul><li>Shows fewer signs of erosion </li></ul>
  112. 116. Humid Climate <ul><li>More weathering </li></ul><ul><li>More erosion </li></ul><ul><li>More deposition </li></ul><ul><li>Rounded hills </li></ul><ul><li>Less steep slopes </li></ul><ul><li>Promotes lush vegetation </li></ul>82
  113. 117. Landscape Development <ul><li>Humans effect on landscape has been profound </li></ul><ul><li>Farming, mining and construction can cause severe erosion </li></ul>84
  114. 118. Landscape Development <ul><li>The stage of development of a landscape is determined by the duration of time it has been acted upon </li></ul><ul><li>Older landscapes show more effects of weathering and erosion </li></ul>84
  115. 119. Landscape Development <ul><li>Landscapes of New York State (page 2 in reference table) </li></ul><ul><li>Most NYS soils are unsorted sediments deposited by the most recent continental glacier </li></ul><ul><li>Rock types and structures found in NYS were determined prior to glaciation, however glaciers modified the landscape. </li></ul>

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