Science Olympiad Dynamic Planet Vocabulary

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  1. Tarn
    a small mountain lake or pool
  2. Recessional Moraines:
    end moraines behind the terminal moraine that form when the glacier temporarily stops retreating and remains stationary or advances.
  3. Summer ablation:
    surface melt water carries a small load and this often disappears down crevasses.Subglacial debris is moved along the floor of the valley either by the ice as ground moraine or by meltwater streams formed by pressure melting.
  4. Englacial debris: 
    sediment carried within the body of the glacier
  5. Regelation:
    motion of an object through ice by melting and freezing that is caused by pressure differences; this process allows a glacier to slide past small obstacles on its bed.
  6. Entrainment:
    the picking up of loose material by the glacier from along the bed and valley sides. Entrainment can happen by regelation or by the ice simply picking up the debris
  7. Roche moutonnée:
    A knob of bedrock carved into an asymmetrical hill.
  8. Kettles:
    often found as kettle lakes, formed by bits of glacial ice breaking off and forming depressions in the ground, which then melt.
  9. Eskers:
    long, winding ridges of stratified deposit, left behind by glacial meltwater streams.
  10. Kame:
    smaller, irregularly shaped hills of deposit that accumulate as a glacier retreats.
  11. Drumlins:
    elongated, streamlined hills made out of deposited till. The steeper side of the drumlin points in the direction in which the ice flowed.
  12. Subglacial lakes:
    bodies of freshwater that are contained deep within the layers of ice sheets. The largest known subglacial lake is Lake Vostok, located beneath the (East) Antarctic Ice Sheet.
  13.  Tidewater Glaciers:
    when glaciers end up reaching the sea, but instead of spreading out to form ice sheets or shelfs, they terminate at the shoreline. Tidewater glaciers often have high acceleration rates.
  14. Plucking:
    the process which involves the glacier freezing onto the valley sides and subsequent ice movement pulling away masses of rock.
  15. Glacial periods:
    times in the Earth's history where average global temperatures were approximately 6 C lower and glaciers covered much of the planets surface.
  16. Till:
    debris deposited directly by a glacier. It is unstratified and unsorted. Terminal and recessional moraines consist of till.
  17. Obliquity:
    Tilt variations in the axis of rotation
  18. Orbital eccentricity:
    the orbit of the earth around the sun is not a circle, but is elliptical and also varies. This eccentricity is a minor cause for seasons.
  19. Precession:
    the earth's axis of rotation wobbles which results in minor fluctuations in the amount of solar radiation we receive
  20. Piedmont Glacier:
    Valley Glacier that has flowed out onto an adjacent plain
  21. Ice stream:
    • (1) a current of ice in an ice sheet or ice cap that flows faster than the surrounding ice
    • (2) sometimes refers to the confluent sections of a branched-valley glacier
    • (3) obsolete synonym of valley glaciers.
  22. Moraine:
    any ridge or mound of glacial debris that is deposited in glaciated regions. Moraines can consist of boulders, gravel, sand and clay, among other sediments.
  23. Arete:
    sharp parallel ridge of rock that resists erosion, formed by two cirque glaciers coming together but not joining. The glaciers are usually flowing down opposite sides of a mountain.
  24. Nunatuck:
    a rocky crag or small mountain projecting from and surrounded by a glacier or ice sheet
  25. Outlet glaciers:
    glaciers that occupy valleys that extend below the coverage of ice field.
  26. Paternoster lakes:
    a series of tarns connected by a single stream or a braided stream system
  27. Sub polar glacier:
    a glacier whose temperature regime is between polar and temperate; usually predominantly below freezing, but could experience extensive summer melt.
  28. Shear margin:
    the point where fast-flowing glacier ice meets slow-moving ice or rock.
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Science Olympiad Dynamic Planet Vocabulary
Some of the key terms for Science Olympiad Dynamic Planet 2014
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