Ocean part exam, real one

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Ocean part exam, real one
2011-12-05 23:01:19

ocean exam
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  1. Seawater composition
    - sodium chlorite, metals, other salts, dissolved gases.

    -most of the salt in seawater is sodium chloride (table salt)
  2. Pycnocline
    layer of rapidly changing density

    -surface currents occur

    affect only 10% of oceans water
  3. Thermocline
    -layer of rapid temperature change

    absent at high altitudes
  4. Halocline
    • -layer of rapid salinity change
    • seperates layers of different salinity of ocean
  5. How is salinity measured?
    -parts per thousand

    3.5% or 35 %
  6. Active continental margin
    -ocean lithosphere subducted beneath continent

    -associated with deep ocean trenches

    • -may have little or no accumulation of sediments
    • accumulations come from accretionary wedges
  7. Passive continental margins
    -continental self

    -not associated with plate boundaries

    -experience little volcanism and few earthquakes

    -gently sloping from shoreline to deep ocean
  8. Deep ocean basins
    -almost 30% of Earth's surface

    -most are located in pacific ocean
  9. Deep ocean basins features
    -deep ocean trenches

    -abyssal plains


    -oceanic plateaus
  10. (deep ocean basins) Deep ocean trenches
    deepest parts of the ocean

    -most are found in Pacific

    -contain voclanic arcs and continental volcanic arcs
  11. (deep ocean basins) Abyssal Plains
    -the most level places on Earth

    -sites of thickest accumulations of sediment

    -found in all oceans, esp Atlantic ocean
  12. (deep ocean basins) Seamounts
    -isolated volcanic peaks

    many form near oceanic ridges
  13. (deep ocean basins) Guyouts
    -submerged, flat-topped volcanoes
  14. (deep ocean basins) Oceanic plateaus
    -similar to continental flood basalt provinces
  15. Mid-ocean ridge
    -longest topographic feature on Earth

    • -divergent plate boundary
    • -new crust created
  16. (mid-ocean ridge) Ocean ridge
    • -broken into segments
    • -segments seperated by tranform faults

    -consists of layers of newly formed basltic rocks
  17. (mid-ocean ridge) Rift valley
    -volcanic cones common

    -rugged topography

    -similar to continental rift valleys
  18. (coastal environment) Coast
    -area behind the beach
  19. (coastal environment) Beach zone
    Backshore and foreshore
  20. (beachzone) Backshore
    dunes or berms
  21. (beachzone) Foreshore
    -high and low tidal reaches

    -surf zone
  22. (coastal environment) Near shore
    -beach disposition of sediments

  23. (coastal environment) Offshore
    -little to no beach sediments
  24. Cause of tides
    -EArth, sun, and moon gravitational interactions
  25. Spring tide
    extreme high and low tides

    -when sun, moon, and earth are aligned
  26. Neap tide
    moderate high and low tides

    -when the sun and moon are perpendicular to each other in position to earth
  27. (Waves) Orbital motion
    -seen best in swells at sea

    -orbital motion is broken down in coastal areas
  28. (Waves) Breakers
    -when waves break or spill oer themselves

    • -At sea, waves do not touch bottom
    • at the coast, they do

    -caused by frictional dragging of orbital motion along shore floor
  29. (Waves) Wave refraction
    -water waves can be refracted, or bent

    -this physical action leads to coastal straightening
  30. Coastal straightening
    -by wave refraction
  31. Erosion features
    -sea cliff

    -sea cave

    -sea stack

    -sea arch
  32. Longshore current
    - current drives the longshore drift of beach sediments

    - occurs in an even coast
  33. (erosion features) Sea cave
    -sea caves are formed by wave action and erosion
  34. (erosion features) Sea stack
    -left over piece from a sea cliff
  35. (erosion features) Sea arch
    -water erodes through a slice of rock
  36. longshore drift
    -primary method to transport sediment along the beach

    -always parallel direction facing the face of the beach
  37. longshore drift creates...
    -bay barrier


    barrier spits
  38. bay barrier
    -if completely cut off by barrier becomes a lagoon
  39. Tambolos
    -beach sediment deposited behind a sea stack
  40. what causes Beach erosion?
    -due to waves

    -due to storms- Hurricanes
  41. (depositions) Barrier Beach
    is a deposition of sand offshore


    -created by longshore drift

    --act as a barrier or protection of the mainland from wave action
  42. (depositions) Barrier island
    -larger than barrier beach


    -tempting landscape to build in

    -act as a barrier or protection of the mainland from wave action