Chapter 14 -- Glaciers and Glaciation

Question 0

> 99% of glacial ice is in ________ and _________

Cover about ##% of the Earth’s land surface

Answer 0

Antarctica and Greenland

10%

Question 1

a mass of compacted and recrystallized ice that flows under its own weight (excludes: ___ ___ and ______ _______)

Answer 1

Glaciers

Sea Ice and Frozen Seawater

Question 2

Long, narrow tongues of ice
Typically much smaller than continental glaciers
Flow from \_\_\_\_\_\_ to \_\_\_\_\_ elevations
Confined within mountain valleys
Also called \_\_\_\_\_\_/\_\_\_. \_\_\_\_\_\_\_

Answer 2

Valley Glaciers
Higher to Lower
Alpine/Mtn. Glacier

Question 3

Cover large areas and are not confined by topography
Flow outward in all directions from the center of accumulation
Present today in _________ and __________, with ice thicker than #,### meters.
Covered large parts of North America from Washington to Maine during the Pleistocene.

Answer 3

Continental Glaciers
Antarctica and Greenland
3,000

Question 4

Similar to continental glaciers but much smaller

Some develop from valley glaciers when they grow over the top of a divide.

Answer 4

Ice Caps

Question 5

Glaciers Contain a little more than #% of all water on Earth
##% of all the fresh water are located here.
Store this water for long periods, but melting and sublimation return it to the hydrologic cycle.

Answer 5

2%

75%

Question 6

A process by which ice turns into water vapor without an intermediate liquid phase.

Answer 6

Sublimation

Question 7

Compaction of snow and elimination of pore space results in a granular ice called ____
Further burial recrystallizes _____ into _______ ___.
Fresh snowflakes are about ##% air.

Answer 7

Firn
Glacial Ice
80%

Question 8

Glaciers may slide down slope over their underlying surface, a phenomenon called _____ ____.

Answer 8

Basal Slip

Question 9

Most of their movement is accomplished by ______ ____, a type of deformation that takes place in response to stress.

Answer 9

Plastic Flow

Question 10

Glaciers can be described in terms of their ______.

Answer 10

Budget

Question 11

Upper part of a glacier where snow is covered year around.

Answer 11

Zone of Accumulation

Question 12

Lower are where losses (_______) exceed gain.

Answer 12

Zone of Wastage

melting

Question 13

Elevation to which snow melts during the warm season.

Answer 13

Firn Limit

Question 14

if firn limit moves down the glacier.

Answer 14

+ ve Budget

Question 15

if firn limit moves up the glacier.

Answer 15

• ve Budget

Question 16

As glaciers move down river valleys, they widen, deepen, and straighten the valley.

Answer 16

U-Shaped Valley Trough

Question 17

Smaller tributary glacial valleys left stranded high above more quickly eroded central trunk valleys.

Answer 17

Hanging Valleys

Question 18

Steep sided, half bowl shaped recesses carved into mountains at the heads of glacial valleys.

Answer 18

Cirques

Question 19

Water filled cirque.

Answer 19

Tarn

Question 20

Sharp ridges separating glacial valleys.

Answer 20

Aretes

Question 21

Sharp peaks remaining after cirques have cut back into a mountain on several sides.

Answer 21

Horns

Question 22

Coastal inlets formed by drowning of glacially carved valleys by rising sea level.

Answer 22

Fiords

Question 23

are boulders that are found far from their source and eroded and transported by glaciers.

Answer 23

Erractics

Question 24

is unsorted, unstratified sediments deposited directly by glacial ice.

Answer 24

Till

Question 25

Is layered and sorted to some degree; deposited in lakes or braided streams associated with glaciers.

Answer 25

Stratified Drift

Question 26

Vast blankets of sediment that form in front of the glacier as it melts.

Answer 26

Outwash Plains

Question 27

Deposits of braided streams that form long, narrow deposits of stratified drift.

Answer 27

Valley Trains

Question 28

Conical hills created when a stream deposits sediment in a depression on the glacier’s surface.

Answer 28

Kames

Question 29

Snake like deposits from sub glacial streams.

Answer 29

Eskers

Question 30

Consist of couplets of dark and light, laminated, fine grained sediment
Represent seasonal deposition

Answer 30

Varves

Question 31

Are probably rafted into lakes by ice blocks.

The ___ of a glacial lake may be determined by counting the layers.

Answer 31

Dropstones

Age

Question 32

Proposes that minor irregularities in the Earth’s rotation and orbit can alter the amount of solar radiation received by the Earth and thereby affect climate.

Answer 32

The Milankovitch Theory

Question 33

Orbital Eccentricity has a ________ year cycle.

Answer 33

100,000 Years

Question 34

1.5° variance in tilt of axis has a ______ year cycle

Answer 34

41,000 Years

Question 35

Precession of Axis has ____ year cycle.

Answer 35

23,000 Years