Page 367 - Laboratory Manual in Physical Geology

ice reaches its maximum thickness and extent during surface reflects sunlight back into space. Without sea ice,
the winter months, then it melts back to a minimum the ocean absorbs the sunlight and warms up. Sea ice
extent and thickness during the summer months. In also provides the ideal environment for animals like polar
the northern hemisphere, Arctic sea ice reaches its bears, seals, and walruses to hunt, breed, and migrate as
minimum thickness and extent by September. Sea ice survival dictates. Some Arctic human populations rely on
helps moderate Earth’s climate, because its bright white subsistence hunting of such species to survive.

MOUNTAIN CONTINENTAL
WATER BODIES OF GLACIATED REGIONS
GLACIATION GLACIATION
Small lake in a cirque (bowl-shaped depression formed by a cirque
Tarn glacier). A melting cirque glacier may also fill part of the cirque and X
may be in direct contact with or slightly up-slope from the tarn.
Lake formed behind a mass of ice sheets and blocks that have
wedged together and blocked the flow of water from a melting
Ice-dammed lake X X
glacier and or river. Such natural dams may burst and produce a
catastropic flood of water, ice blocks, and sediment.

Paternoster lakes Chain of small lakes in a glacial trough. X

Long narrow lake in a glacial trough that was cut into bedrock by
the scouring action of glacial ice (containing rock particles and
Finger lake X X
acting like sand paper as it flows downhill) and usually dammed by
a deposit of glacial gravel (end or recessional moraine).
Small lake or water-saturated depression (10s to 1000s of meters
Kettle lake or wide) in glacial drift, formed by melting of an isolated, detached block
kettle hole of ice left behind by a glacier in retreat (melting back) or buried in X X
outwash from a flood caused by the collapse of an ice-dammed lake.
Narrow marsh, swamp, or very shallow lake in a long shallow
Swale X
depression between two moraines.

Lake formed at the margin (edge) of a glacier as a result of
Marginal glacial lake accumulating meltwater; the upslope edge of the lake is the X X
melting glacier itself.

Stream of water derived from melting glacial ice, that flows under
Meltwater stream the ice, on the ice, along the margins of the ice, or beyond the X X
margins of the ice.
Stream that is not large enough and powerful enough to have cut
the valley it occupies. The valley must have been cut at a time when
Misfit stream X X
the stream was larger and had more cutting power or else it was cut
by another process such as scouring by glacial ice.
Saturated, poorly drained areas that are permanently or intermittently
Marsh or swamp covered with water and have grassy vegetation (marsh) or shrubs X X
and trees (swamp).

FIGURE 13.7 Water bodies resulting from mountain or continental glaciation.

Glaciers and the Dynamic Cryosphere ■ 337