Download Ice, Wind, and Wasting “By the breath of God ice is given, And the

Ice, Wind, and Wasting
“By the breath of God ice is given, And the broad waters are frozen.”Job 37:10
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glacier – thick ice sheet that slowly moves under its own weight
continental – sheets that cover huge areas of relatively flat land
(Antarctica, Greenland)
valley/alpine – smaller, highland glaciers
 crevasse – deep crack/fissure in glacier
cirque – bowl shaped depression formed by a glacier in the valley where it begins
horn – three or more cirques cut into a mountain peak (Matterhorn)
 striae – deep grooves and scratches in bedrock in the direction of the
glacier's movement
till – broken rock carried by a glacier
moraine – heap/ridge of till left by a retreating glacier
drumlin – formed when an advancing glacier overruns its old moraines
 outwash – sand, gravel, other sediments washed out from beneath a glacier by
water from melting ice
 Ice Age – period of history during which much of earth's high latitudes were
apparently covered with glaciers; glaciers and cold weather did not cover the
entire earth during the Ice Age; only present
 deflation – removal of loose particles of sand and soil by wind; blowout –
shallow or hollow depression in ground scooped out by deflation
 desert pavement occurs when wind blows away most loose surface materials over
the years, leaving only pebbles, rocks, and boulders too heavy for wind to
move
 sandstorm – strong windstorm in an arid region that produces thick clouds of
blowing silt
loess – deposits of clay and silt left by a sandstorm
sand dunes – huge heaps of loose, windblown sand common in deserts and near
beaches; crescent, parabolic, transverse [p.263]
 abrasion – sandblasting action of windblown sand
 mass wasting – general term for movements of rock and soil caused by gravity;
soil creep most common – very slow downslope movement of soil and rock
fragments
 mudflow – rapid downhill movement of loose, water-saturated soil
 landslide – sudden slide of rock or soil down a slope
avalanche – landslide involving snow or ice
 rockslide – landslide consisting primarily of bedrock
rockfall – not a landslide; piece of rock breaking off rocks from a cliff
 how to prevent erosion – planting trees/ grass/vegetation; planning drainage;
terracing
Activity
1. Have each pair take a handful of play dough and smooth it out like a pancake.
Ask one student from each pair to take a model glacier ice cube and drag it (rough
end down) slowly, one way across the play dough while pushing down with medium
pressure. (Pairs may do this twice so each student has the chance to participate.)
2. Have each pair of students look closely at their model glaciers and playdough
landscapes and discuss the following questions together:
a. What kind of marks does the glacier make in the play dough?
b. Does the glacier leave anything behind (dirt, rocks)?
c. Are there interesting features on the surface of the glacier like
crevasses?
d. How is the dirt and gravel distributed throughout (randomly)?
e. How was the play dough “landscape” affected by the sediment in the
“glacier”
(scratches, grooves, large boulders picked up and then deposited by glaciers)?
5. Now, have each pair of students put their model glacier into a pan and observe
it melting. (This is more similar to a continental glacier, while the scraping
activity
represented an alpine (valley) glacier.) Have each pair of students look closely at
their model glaciers and discuss the following questions together:
a. What do you notice about how the rocks and dirt are distributed by the
melting ice
(sediment is unsorted, piles are of mixed sizes)?
b. Describe the areas and the clues the glaciers left behind.
Homework
Section Review 10.2 (p. 265)
Investigative Plan