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Flashcards

ESS 230 exam 1

mitchscott1993 English 124 cards

Cards in this deck (124)

  1. 1Part of rock cycle we are studyingWeathering to transport to sedimentation
  2. 2Definition of Weatheringthe disintegration or breakdown of rock material
  3. 3Mechanical Weathering defintionno change in chemical composition, just disintegration into smaller pieces
  4. 4Chemical Weathering definitionBreakdown as a result of chemical reactions
  5. 5Types of physical breakup caused by mechanical weatheringPressure release, water (freeze - thaw cycles), crystallization of salt in cracks, thermal expansion and contraction
  6. 6Exfoliationrock breaks apart in layers that are parallel to the earths surface
  7. 7Frost wedgingRock breakdown caused by the expansion of ice in cracks and joints
  8. 8Roles of physical weatheringReduces rock material for transport, increases exposed surface are of rock making it more vulnerable to further weathering
  9. 9Chemical Weathering definitiontransformation/decomposition of one mineral to another
  10. 10DissolutionA substance breaking down and being dissolved in water
  11. 11Dominant ion in surface runoffBicarbonate
  12. 12OxidationDissolved oxygen promotes oxidation of sulfides, ferrous oxides and other native metals
  13. 13HydrationAttachment of water molecules to crystalline structure of a rock, causing expansion and weakness.
  14. 14HydrolysisCombination of H and O in water with rock to form new substances
  15. 15Minerals most resistant and least resistant to weatheringMost: quartz
    Least: Olivine
  16. 16Forms of biological weatheringRoots split rocks apart
    Roots produce acids
    Tree throw
    Burrowing animals
  17. 17Most effective parts of the world of chemical weatheringWarm, moist cliimates (tropics)
  18. 18Most effective regions for mechanical weatheringregions with frequent freeze-thaw cycles
  19. 19Definition of soilSolid earth material that has been altered by weathering/processes that can support life
  20. 20Soil inputsConversion of rock to soil
  21. 21Soil outputsDownslope movement of soil
  22. 22Factors that affect soil thicknessWeathering rate and slope
  23. 23Factors that affect soil formationClimate (temp & precip.)
    Organisms
    Parent Material (mineralogy, grain size)
    Topography (slope, elevation, aspect)
    Time
  24. 24Equilibrium soil thickness on hillslopes1m
  25. 25Additions to soilsAtmospheric inputs: Precip, dust, decomp,
    Horizontal inputs: Floods, tidal exchange
    Litterfall and root turnover
  26. 26Bedrock undergoes weathering to become whatA regolith (soil + saprolite)
  27. 27Saprolite defintionWeathered rock that contains remnant rock structure
  28. 28Soil horrizonsLayers that are NOT deposited, but are zones of chemical action
  29. 29elluviationleaching by infiltrating water
  30. 30illuviationDeposition and accumulation of material leached from higher levels in the soil
  31. 31horizons of soil profile (top to bottom)O-A-B-C
  32. 32AridisolsArid zone soils
  33. 33MollisolsGrassland soils (A horizon)
  34. 34SpodosolsForest soils (thick B horizon)
  35. 35OxiosolsTropical soils (very oxidized)
  36. 36Limits on soil developmentBalance between downward lowering of ground surface, and downward migration of soil horizons.
    Very slow
  37. 37How many years it takes to form and inch of soil500 years
  38. 38Modern rates of soil lossabout 1mm/yr
  39. 39How long it will take to erode a 1m thick soil?~1000 years = lifespan of most major civilizations
  40. 40What is a soil regime?The amount, size, and characteristic sediment transport style in a river. Governed by the amount and size delivered from hill slopes and upsream
  41. 41What soil regime depends onErosional processes, weathering rate, rock properties, soil properties
  42. 42Sediment BudgetSediment inputs from upstream and banks are balanced by sediment transport or changes in sediment storage
  43. 43Types of Erosional ProcessesSoil "Creep"
    Overland Flow
    Landslides
    Glaciers
    River incision into bedrock
    Bank erosion
  44. 44What is a soil creep?Gradual, non-catastrophic downslope movement of weathered material influenced by gravity
  45. 45Define overland flowerosion that occurs when enough flow accumulates to overcome the erosion resistance of the ground surface
  46. 46Where is overland flow most common? Least common?Most common in semi arid landscapes. Least common in forest mountain landscapes
  47. 47Why is erosion by overland flow least common in forest mountain landscapes?Rainfall tends to infiltrate into the ground, and vegetation provide erosion resistance.
  48. 48Factors controlling erosionclimate
    Slope
    Vegetation
    Erodibility/lithology
    landuse
  49. 49Amount of precipitaion that yields mmost sediment~10-20inches
  50. 50How much of earths water is fresh?3%
  51. 51Of water on land, how much is in inland seas, ice, and groundwater99%
  52. 52Watershed/Drainage BasinPortion of land that a stream drains into
  53. 53What is a tributarySmaller streams that feed larger streams with a drainage basin
  54. 54What is the Base level of a streamThe level below which a river cannot incise
  55. 55Definition of RiverA body of water that flows along a clearly defined natural passageway and transports particles and/or dissolved substances
  56. 56Factors controlling stream behaviiorslope
    Cross-sectional area
    velocity of waterflow
    discharge
    load
  57. 57As you go down stream, what happens in terms of discharge, gradient, cross-sectional area, and width to depth rationDischarge increases
    Gradient decreases
    Cross-sectional area increases
    width:Depth ratio increases
  58. 58Do deeper streams move faster than shallow streams? if yes, whyYes because there is less resistance from the stream bed
  59. 59Velocity determination methodFloat method. Measure distance and time it takes to travel that distance
  60. 60What are river levels measured asA stage, must be converted to discharge via a rating curve
  61. 61Recurrence intervalthe average time between floods of a given size. interval of 10 years is called a "10-year flood"
  62. 62Graph that shows stream dischargeHydrograph
  63. 63When is discharge the greatest?In the spring when the snow melts, and in the fall when it starts raining a lot
  64. 64Three types of LoadBed load
    Suspended load
    Dissolved load
  65. 65Percent of of bed load of total load in a stream5-20%
  66. 66Where do suspended sediments tend to settle?Where velocity decreases, such as in lakes and oceans
  67. 67Why does sediment size normally decrease in size downstreamCoarse bed load is gradually reduced by abrasion. Coarser heavier materials generally settle first.
  68. 68What types of sediment is carried out to the ocean?Silts,sands, and clays
  69. 69How much of the earths surface is land? Ocean? Continental Margins?land = 30%
    Sea = 60%
    Continental Margins = 10%
  70. 70What is the continental crust made of?Granite (not so dense)
  71. 71What is the oceanic crust made of?Basalt (denser)
  72. 72What happens when two ocean plates collide?Form a submarine trench
  73. 73What happens when two continental plates collide?Form high mountain ranges
  74. 74What happens when occurs when ocean and continental plates collide?Form mountains and trenches. And when subduction occurs
  75. 75Features of Continental shelfSmooth, gentle slope
    glacial ice melted and flooded portion of continent
  76. 76Features of continental slopesteep, rough topography
    submarine canyons
    not eroded by rivers
  77. 77Features of continental riseMore gentle gradient and relief
    sediment from land piled on ocean crust
  78. 78What are the two types of continental margins?Trailing edge margins and collision margins
  79. 79What is a trailing-edge margin?When continental and oceanic plates move in same direction and at the same speed
  80. 80What is a collision margin?When continental and oceanic plates move toward each other
  81. 81Classification of marine sediments of fluvial sediments?Lithogenic
  82. 82Where does lithogenic sediment occur?Dominates near continents.
    glacial at high latitudes, fluvial at all latitiudes
  83. 83Where does biogenic sediment dominate?Away from lithogenic sediments (usually away from continents)
  84. 84Where does authingenic sediment dominate?Dominates away from continents (not very high productivity)
  85. 85What happens to sea level as temp decreasesSea level drops
  86. 86What happens to sea level when temp increasessea level rises
  87. 87What is a turbidity current?A slurry of sediment that moves down the continental slope
  88. 88what major process formed pudget sound?Pudget sound was formed by a giant glacier
  89. 89What is salinity?The amount of salt dissolved in water
  90. 90What is the approximate salinity of salt water?~35ppt
  91. 91Defintion of a fjordEstuary with glacial origin.
    Deep with shallow sill near mouth
  92. 92Define a deltariver mouth receiving much sediment. Estuary filled with sedimant
  93. 93Major source of sediment in puget sound?River discharge
  94. 94What is plume transport?Turbid surface water, river momentum, tides, wind
  95. 95What is flocculation?silt and clay particles clump together to form larger pieces which sink quickly
  96. 96down stream trend of discharge, width, depth, velocity, gradient, and grain sizeDischarge increases, width increases, depth decreases, velocity increases, gradient decreases, grain size deceases
  97. 97Characteristics of alluvial riverserodible channel boundaries
    sediment supply > transport capacity
    Input >= Output
  98. 98Types of Alluvial channelsCascade
    Step-pool
    Plane-bed
    Pool & riffle
    Dune - ripple
  99. 99Order types of alluvial channels in increasing gradient and degree it can carry sedimentDune-ripple, pool & riffle, plane-bed, step-pool, cascade
  100. 100Most common type of alluvial river channelPool-Riffle
  101. 101How is pool-riffle channels characterizedBy alternating sequence of bars and pools
  102. 102What is the deepest part of a stream called?The thalweg
  103. 103What does the bankfull discharge equate to?roughly a 2-year reccurence interval flow
  104. 104What are the three types of channel patterns?Straight
    Meandering
    Braided
  105. 105Where are straight channels most common?Where streams are confined by topography. Often mountain streams
  106. 106Why are straight channels uncommon?interaction between flow & eroding/depositing bed cause organized bar deposition.
  107. 107Meandering rivers leads to formation ofCut banks and point bars
  108. 108Where is velocity the highest on a meandering river?On the outside of bends
  109. 109What is it called when meanders intersect and cut a off a meander loop?An oxbow lake
  110. 110Defintion of Braiding channelsmultiple converging & diverging channels separated by mid-channel bars
  111. 111Characteristics of braided channelshigh sediment load (relative to water)
    Constantly changing course
    many small islands (mid-channel bars)
    usually carry coarse sand and gravel
  112. 112Why do braided channels just stay as one single channel?Amount of bedload too much for transport capacity
  113. 113Braided channels typical in regions with:easily erodible banks
    high sediment load
    common near mountains and glaciers
  114. 114Define an estuarySemi-enclised coastal environment where freshwater and ocean water meat and mix
  115. 115Definition of DeltaSedimentary deposit at mouth of river that causes coastline to protrude into ocean
  116. 116what is a coastal-plain estuary?Drowned river valley
    V-shaped in cross section
  117. 117What is a Fjorda drowned glacial valley
    U-shaped in cross section
  118. 118Bar-Built estuary (lagoon)sand spit or barrier encloses emboyment
  119. 119Tectonic estuarydown-dropped basin
    located near ocean, and seawater floods basin
  120. 120Sediment breakdown of estuaries10% sand
    90% mud and clay
  121. 121Estuarine circulationthe denser salt water flows under the less dense fresh water at an estuary forming a salt wedge
  122. 122What is the boundary with underlying salt water called?halocline
  123. 123Fjord circulationDeep sills provide thorough mixing of deep water. Shallow sills provide poor mixing of deep water
  124. 124What is turbidity?Sediment in suspension

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Flashcards on ESS 230 exam 1, created by mitchscott1993 on 28/10/2014.
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