Quiz Review #3 – Water Systems

Be able to define and possibly draw a pictorial representation of:

  • Continental shelf
  • Continental slope
  • Volcano
  • Seamount
  • Volcanic island
  • Guyot
  • Canyon
  • Trench
  • How lakes are formed
  • Tributaries
  • Watersheds
  • Continental Divide
  • Acid precipitation
  • Flood plains
  • Landlocked lake
  • Water enters lakes through precipitation, ground water, and inlets.

Glaciers

Glaciers form by the accumulation of snow and ice above the snowline. Glaciers begin to form when more snow falls during the winter than melts and evaporates in the summer

Alpine Glaciers:

  • Long, narrow bodies of ice that fill high mountain valleys
  • Many of them move down sloping valleys from a cirque, a bowl-shaped hollow with steep walls located among the peaks
  • Alpine, HimalayaMts., Andes, Alps, New Zealand

Continental Glaciers:

  • Massive ice sheets that are broad, and extremely thick
  • Cover large areas of land near the earth’s polar regions
  • Glaciers of this type build at the center and slope outward to flow toward the sea in all directions
  • Greenland, Antarctica
  • East Antarctic Ice Sheet: Land Based
  • West Antarctic Ice Sheet: Ocean Based

Glacier Movement:

The combined pressure of the weight of itself and gravity cause glaciers to flow downhill.

Basal Slip

  • Weight of overlying ice exerts pressure to melt ice in contact with ground
  • Melted water along the base of the glacier helps to allow it to slide forward

Internal Plastic Flow

  • Pressure deforms grains of ice causing them to slip over each other inside the glacier

The center and upper areas of a valley glacier (alpine glacier) flows the fastest. The sides and bottom move more slowly because they rub against the walls and floor of the valley. Because of uneven movement crevasses (large cracks) form.

Ice sheets can move out over the water to form Ice Shelves that break off or fall into the water to become icebergs.

Glacial Erosion

  • Glaciers can gather and move immense amounts of bedrock
  • Rocks picked up by glaciers gouge deep grooves in the bedrock the glacier travels over

Alpine Glacial Erosion Landforms:

  • Cirque- forms when the upper part of a glacier removes blocks of rocks from the surrounding cliffs

Continental Glaciers:

  • Erode the landscape by scraping and gouging grooves into bedrock

Glacial Deposition

  • Glacial Till: The mass of rocks and finely ground material carried by a glacier, then deposited when the ice melted
  • Moraines:
  • Ground Moraines: Ground moraines are till covered areas with irregular topography and no ridges often forming gently rolling hills or plains.
  • Terminal Moraines: the hilly ridge at the lower end of a valley glacier
  • Kettles: lakes formed by a chunk or glacier being buried with the till. It melts forming a depression.

The Great Lakes

  1. Glacial erosion widened and deepened existing river valleys
  2. Terminal moraines blocked off river flow to south
  3. Meltwater filled lakes as glacier retreated
  4. After glacial period, crust rose when weight of ice was removed
  5. This caused lakes to drain more rapidly – formed Niagara Falls

Ices ages: Long periods of climatic cooling where glaciers repeatedly advance over continents

Periods of glaciations cause an Ice Age

How does water from a glacier join back with the water cycle.