Geology test 3 (glaciers)
2. Where is the largest existing glacier located?
Antarctica
3. Which is the only continent that does not presently have glaciers?
Australia
10. There is good evidence that variation in solar energy, as evinced by sunspot activity cycles, is responsible for short-term climatic variations.
F
5. Valleys carved by glaciers are distinctive because they are V-shaped in cross-section.
F
6. A conical hill of stratified drift is an esker.
F
8. A strong correlation has been established between periods of intense volcanism and short-term glacial cooling.
F
3. The present glacial landscapes mainly formed during the ____________________ Epoch, which lasted from ____________________ years to ____________________ years ago
Pleistocene, 1.8 million, 10,000
1. The Little Ice Age ended in the mid to late 1800s.
T
11. The decade from 2000 to 2009 was the hottest on record so far.
T
2. Glaciers are geologically important because they erode, transport, and deposit so much material.
T
3. Basal slip becomes a more important means of glacier movement in warmer months when more meltwater collects at a glacier's base.
T
4. A steep-walled, pyramidal peak formed by headward erosion of cirques.
T
7. End moraines continue to grow as long as the ice front remains stationary.
T
9. Earth's orbit varies from nearly circular to more elliptical in a roughly 100,000-year cycle.
T
10. The zone of ____________________ is the portion of a glacier where additions exceed losses.
accumulation
12. In general, rates of glacial flow are greatest in the zone of ____________________.
accumulation
8. A glaciers budget is balanced when
additions to the zone of accumulation equal losses in the zone of wastage.
15. Ice Ages
are the result of variations in the amount of solar heat received.
11. A glacial landform that forms at the head of glacial valleys or troughs is called a(n) ____.
cirque
7. The two major types of glaciers are ____________________ and ____________________.
continental, valley
13. The presence of ____________________ in the upper 40 m or so of a glacier indicates that this portion behaves not as a plastic, but as a(n) ____________________ solid.
crevasses, brittle
16. Any sediment deposited as a result of glacial activity is known as glacial ____________________.
drift
15. The Matterhorn in Switzerland is a glacial ____________________ landform known as a(n) ____________________.
erosional, horn
4. When snow thaws and refreezes, which results in a loss of air and pore spaces, the result is ____________________.
firn
12. Straight scratches on rock surfaces created by glacial abrasion are known as what?
glacial striations
2. An ice mass of compacted and recrystallized snow that flows under its own weight on land is called a(n) ____________________.
glacier
1. The climatic event that began with cooling in about AD 1300 and lasted until the middle 1800s is known as the Little ____________________.
ice age
5. In the process of sublimation
ice changes directly into water vapor.
9. In a cross-section of a glacier, where do the greatest flow velocities occur?
in the few tens of meters below the surface
11. The zone of wastage is the portion of a glacier where ____________________ exceed ____________________.
losses, accumulation
7. If glacial ice were a rock it would be a(n) _______ rock.
metamorphic
5. Glaciers move primarily by ____________________ flow.
plastic
10. A glacial landform produced primarily by plucking rocks on the downstream side and smoothing by the glacier on the upstream side is called a(n) ____.
roche moutonnée
14. The fine, clay- and silt-sized particles that result from glacial pulverization of rock is known as ____________________.
rock flour
6. The three stages involved in the formation of a glacier are the precipitation of ____________________; the formation of ____________________ by partial thawing, refreezing, and crystallization; and compaction and recrystallization to produce ____________________.
snow, firn, glacial ice
8. A glacier that is now longer flowing is called a(n) ____________________ glacier.
stagnant
13. What is a lake formed within a cirque called?
tarn
9. The distal end or edge of the glacier is called its ____________________.
terminus
14. Glacial till is ____.
unstratified sediment deposited directly by a glacier
4. A glacier that is unconfined by topography and has tributaries is a
valley glacier.
17. Finely laminated, alternating light and dark layers of sediment deposited in a glacial lake are known as glacial ____________________.
varves
1. When did the Pleistocene Ice Age end?
10,000 years ago
6. A glacier begins to flow when the ice reaches what critical thickness?
40 meters