Chapter 9 Geo

Front 1

_________________ in North America covered essentiallyall of Canada and much of the northern UnitedStates

Back 1

Pleistocene glaciations

Front 2

Glacial sediments and erosional activity (especially duringthe Pleistocene epoch) have helped shaped much of what....

Back 2

the topography and near-surface geology of northern North America.

Front 3

snowstorms are a Combination of Altitude and Latitude

Back 3

false - glaciers

Front 4

to form glacier - There must be sufficient moisture in the air, and thus thenecessary precipitation

t/f

Back 4

true

Front 5

firn

Back 5

Packing causes the ice to recrystallized into a denser ice called

ex: snow turns to ice

Front 6

Alpine Glaciers – (also known as ...) occur at high altitude (cooler temperatures)

Back 6

mountain or valley glaciers

Front 7

Continental Glaciers – (also known as ice caps or icesheets) occur near the poles (over land); they are larger andrarer

T/F

Back 7

true

Front 8

Glaciers flow as ______ ice masses and at different rates;overall movement is ____ slope

Back 8

plastic

down

Front 9

T/F

Higher and more centralportions in the glacier is faster –flow freely and rapidly

Back 9

Tru

Front 10

Glacier encounters water and the break away is called

Back 10

Calving

Front 11

Ablation

Back 11

The set of processes by which ice is lost from aglacier is collectedly called Ablation

ex: (melting of snowor ice, evaporation, sublimation, calving, or erosiveremoval of snow by wind).

Front 12

Above equilibrium line is where accumulation occurs?

t/f

Back 12

true

below it is where ablation occurs

Front 13

Glacier becomes thickand longer is called

Back 13

- Advancing

Front 14

Summer: ablation exceedsaccumulation – this is called?

Back 14

Retreating.

Front 15

Overall glacial movement is slowand steady (a few tens of metersper year)

t/f

Back 15

true

Front 16

Volume and Speed determinesamount of _____ in glaciers

Back 16

erosion

Front 17

define plucking

Back 17

Plucking is glacial erosion that occurs as ice freezes ontorock and tears away rock fragments as the ice moves on

Front 18

erosion on continental glacier looks like:

Back 18

Continental glaciers removeall soil, plants, and small hills.

Front 19

erosion on alpine glacier looks like:

Back 19

change Vshapedvalleys to U-shaped.

Front 20

Glacial striations are

Back 20

scratches or gouges cut into bedrock by glacial abrasion.

Front 21

Glacial cirque is ...

Back 21

Bowl shape depression cause by plucking at the head of an alpine glacier

Front 22

An arête is a thin, almost knife-like, ridge of rock which istypically formed when...

Back 22

two glaciers erode parallel U-shaped valleys.

Front 23

Glacial horn:

Back 23

a sharp peak formed where the ridges separating three or more cirques intersect.

Front 24

Water in, on, and under glaciers (pluvial processes) doesn't move any sediments?

t/f

Back 24

False

it moves much sediment as well

Front 25

Till

Back 25

is that unsorted material that is deposited directly by ice

Front 26

Drift is any material deposited by glaciers or theirmeltwater

t/f

Back 26

t

Front 27

Outwash: Till may be transported and redeposited by the ____

Back 27

water

Front 28

Moraines are parallel features deposited at top oralong sides of glaciers.

Back 28

false

linear

bottom

Front 29

Most of the United States is in a zone of easterlies

t/f

Back 29

f

westerlies, in which winds generally blow from west/southwest to east/northeast.

Front 30

Different regions of the earth are characterizedby different

Back 30

prevailing wind directions.

Front 31

Movements of air, or wind, take place in responseto _________________ in the atmosphere, which are related to ___________.

Back 31

pressure differences

temperature differences

Front 32

Wind erosion consists of either

Back 32

abrasion or deflation

Front 33

Wind abrasion

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- the erosion of a solid object by the impact of windblown particles.

Front 34

Wind deflation -

Back 34

the wholesale removal of loose sediment by the wind.

Front 35

Vegetation is critical to reducing the effects of winderosion

t/f

Back 35

t

Front 36

wind abrasion

If the winds is predominantly from one direction, rocksare planed or flattened on the upward side.

t/f

Back 36

t

Front 37

Ventifact:

Back 37

“wind made rocks” rock polished and faceted by windblown sand

Front 38

Wind deposition feature - Dune A low mound or ridge, usually made of sand

t/f

Back 38

t

Front 39

Another Wind deposition feature is called Loess

Front 40

Loess is mainly composed of

Back 40

silt.

Front 41

Loess can originate from winds that blew over either

Back 41

desert or glacial areas

Front 42

Silt is fertile t/f

Back 42

t

Front 43

Rapid development of desert-like conditions onmarginally habitable land caused by

Back 43

human activities such as deforestation, agriculture, and overgrazing