READING QUESTIONS: GlaciersGEOL131Winter 2017

NAME______DUE: Tuesday, March 14th 60pts

Glaciers: A Part of Two Basic Cycles (p. 192-195)

  1. Match each type of glacier to its description: (2 pts)
  1. AlpineIce from larger ice masses flowing through a valley to the ocean_____
  1. ContinentalSmall in size; form in mountains at high elevations_____
  1. OutletCover uplands and elevated plateaus; larger than alpine glaciers_____
  1. Ice capVery large; completely bury underlying terrain_____
  1. EXTRA CREDIT: Is the North Pole covered by glacial ice? YES or NO

Formation and Movement of Glacial Ice (p. 195-198)

  1. What is the snowline?
  2. The depth below which plastic flow occurs
  3. The highest altitude at which snow can become glacial ice
  4. The elevation above which snow remains all year round
  5. All of the above
  1. What isplastic flow?
  2. Microscopic layers of ice crystals sliding over one another under pressure
  3. The entire glacier sliding downslope as a single unit
  4. The movement of meltwater through a glacier
  5. The carving of ice tunnels beneath a glacier
  1. Why does the zone of fracture behave in a brittle fashion? (2 pts)

______
______
______
______

  1. What climate condition must exist in a region in order for glaciers to form? (Circle one answer.)
  2. More snow must fall each winter than melts each summer
  3. More snow must melt each winter than falls each summer
  4. There must be high amounts of snowfall year round
  5. The Earth must be in an Ice Age
  6. Prevailing winds must be coming from the Arctic regions
  7. The region must be at a very high elevation
  1. If accumulation in a glacier exceeds ablation, the glacier front will ______.
  1. EXTRA CREDIT: When a glacier front is retreating, the ice is moving backwards. TRUE or FALSE

Glacial Erosion (p. 199-202)

  1. Fill in the blanks in these sentences from the textbook (p.199): “As a glacier flows over a ______
    bedrock surface, it loosens and ______blocks of rock and incorporates them into the ice. This
    process, known as ______, occurs when meltwater penetrates the ______beneath a

glacier and ______. As the water expands, it exerts tremendous ______that

______the rock loose.” (7 pts)

  1. Fill in the blanks in this sentence from the textbook (p. 199-200): “As the ice and its load of rock

fragments ______over the bedrock, they function like ______, smoothing and

______the surface below.” The previous sentence describes the glacial erosion process called

______. (4 pts)

  1. The process described in question 10 creates two distinctive types of erosional surfaces on rock, both shown in Figure 13. What are these two surfaces? (Circle ONE answer.)
  2. Striations (scratches and grooves) and abrasion
  3. Striations and polishing
  4. Abrasion and plucking
  5. Abrasion and rock flour
  1. Label the erosional features created by alpine glaciation in the following figure: (7 pts)

  1. ______E. ______
  1. ______F. ______
  1. ______G. ______
  1. ______

Glacial Deposits (p. 203-207)

  1. List two differences between till and stratified drift. (2 pts) ______

______
______

  1. Fill in the blanks in these sentences from the textbook (p. 204-205):
    “The sides of a ______accumulate large quantities of ______from the valley
    walls. When the glacier wastes away, the materials are left as ______, called
    ______, along the sides of the valley. ______are formed when two
    valley glaciers ______to form a single ice stream. The till that was once carried along
    the ______of each glacier joins to form a single dark ______of debris
    ______the newly enlarged glacier.” (9 pts)
  1. Fill in the blanks in these sentences from the book(p. 205):
    “An ______is a ridge of till that forms at the terminus of a glacier and is characteristic of

ice sheets and valley glaciers alike.” “…the end moraine forms when the ice is ______and
______near the end of the glacier at a rate ______the forward advance of
the glacier… Although the terminus of the glacier is ______, the ice continues to
______, delivering a continuous supply of sediment…As the ice melts, the till
is ______and the end moraine ______. The longer the ice front remains
______, the ______the ridge of till will become.” (10 pts)

  1. Fill in the blanks in these sentences from the book(p. 205):
    “Eventually, ______exceeds ______. At this point, the front of the
    glacier begins to ______in the direction from which it originally advanced. However,
    as the ice front ______, the conveyor-belt action of the glacier continues to provide
    fresh supplies of ______to the terminus. In this manner, a large quantity of till is
    deposited as the ice melts away, creating a ______, undulating ______. This
    gently rolling layer of till…is termed a ______. (8 pts)
  1. The photo below shows a drumlin. Which way was the ice flowing that deposited this feature?
  2. From the left
  3. From the right
  4. Can’t tell from the photo

  1. Match each glacial landform with the correct description of how it forms. (3 pts)
  1. Kamedeposition of stratified drift by a meltwater stream beneath a glacier_____
  1. Eskerdeposition of stratified drift into depressions in a stagnant glacier front _____
  1. Kettlecreated by melting of blocks of ice left behind as a glacier retreats_____