Glaciation

Question 1

Theory of ice ages

Answer 1

Developed in 1837 by louis Agassiz
evidence for glaciation in regions with no glaciers
The present is the key to the past

Question 2

What is a glacier

Answer 2

large, long lasting river of ice that forms on land, undergoes internal deformation, and creates glacial landforms

Question 3

What are glaciers made of

Answer 3

compressed and recrystallized snow

Question 4

Order these from most to least compacted: Neve, glacier ice, firn, and snowfall

Answer 4

glacier ice, firn, neve, snowfall

Question 5

Do glaciers often carry large sediment loads

Answer 5

yes

Question 6

Where do glaciers form

Answer 6

at high elevation, at high latitudes (near the poles of the earth),

Question 7

Glaciers have a large range in what 2 characteristics

Answer 7

size and age

Question 8

What are 5 terms to describe the zones of a glacier

Answer 8

Zone of accumulation, equilibrium line, crevasses, zone of wastage/ablation, terminus

Question 9

Landforms: glaciers form on land, undergo internal __________, and create glacial landforms

Answer 9

deformation

Question 10

Brittle vs ductile deformation: glaciers deform through _______ deformation at their surface and _______ deformation at depth

Answer 10

brittle
plastic

Question 11

For bedrock erosion is their water under the glacier

Answer 11

yes

Question 12

Is there water under the glacier for plucking and abrasion

Answer 12

no

Question 13

What are the three different ways ice moves

Answer 13

basal sliding, internal flow, and faulting

Question 14

When ice movement occurs, what is picked up from the base of the ice and transported up towards the surface

Answer 14

sediment

Question 15

ice flows from _____ to ______ surfaces

Answer 15

high to low surfaces

Question 16

ice flows from the zone of ________ to the zone of _________

Answer 16

accumulation
ablation

Question 17

Define mass balance

Answer 17

relative rate of accumulation and wastage. how much is being melted at the zone of ablation and how much is accumulating at the zone of accumulation

Question 18

Where would we find an alpine glacier

Answer 18

mountainous areas

Question 19

What are continental glaciers

Answer 19

they cover large areas and are not confined to high elevations

Question 20

What are two types of continental glaciers

Answer 20

Antarctic and greenland

Question 21

What are the two principle types of glaciers

Answer 21

alpine glaciers and continental glaciers

Question 22

Why is a glacier striation formed

Answer 22

when the glacier moves across a rock it scratches it

Question 23

describe a cirque glaciers

Answer 23

accumulates in a bowl like shape in the mountains

Question 24

describe a valley glacier

Answer 24

found in valleys, extending out from mountains

Question 25

describe a piedmont glacier

Answer 25

form where valley glaciers spread out onto a flatter area in a larger valley or on a plain

Question 26

describe temperate glaciers

Answer 26

glaciers hat are near their melting point and have meltwater coming off them year round

Question 27

describe a polar glacier

Answer 27

ice in the glacier is frozen year round and ice loss is primarily from sublimation

Question 28

what is sublimation

Answer 28

transformation of ice to gaseous water - without melting in between

Question 29

describe subpolar glaciers

Answer 29

They are between polar and temperature climate conditions and experience seasonal melting and water runoff

Question 30

describe an ice shelf

Answer 30

the ice from the glacier extends over a water body, water is able to flow underneath

Question 31

describe an outlet glacier

Answer 31

extends outward from continental glaciers or icecaps

Question 32

Does erosion from a glacier cause a V-shaped valley or u-shaped valley

Answer 32

u-shaped valley

Question 33

escribe a horn

Answer 33

erosion occurs when cirques surround the mountain and erode it

Question 34

describe a cirque and aretes

Answer 34

erosion feature that form a rocky ledge between the cirques

Question 35

describe a hanging valley

Answer 35

erosion feature that forms a little ledge and u-shaped valley between mountains

Question 36

describe a paster noster lake

Answer 36

little streams and lakes that fill erosional features

Question 37

describe glacial till

Answer 37

unstratified and unsorted sediment deposited by glaciers

Question 38

What are the 3 types of moraines

Answer 38

medial(travels along the middle of the glacier), terminal, and lateral

Question 39

What do we call sorted sediments deposited by a river flowing under or through a glacier

Answer 39

esker

Question 40

what do we call depressions left by melted ice blocks

Answer 40

kettle lakes

Question 41

What are features of depositions

Answer 41

esker, kettle lakes, drumlins, moraine, glacial till, kame, erratics (boulders)

Question 42

describe an outwash plain

Answer 42

it is found at the terminus end of glaciers. water transports sediments deposited by the glacier.

Question 43

Why are outwash plains different than glacial till

Answer 43

you can find sorted sediments in outwash plains.

Question 44

describe roches moutonnees

Answer 44

hill features formed at the base of glaciers. glacial plucking on the downstream side creates jagged cliff. the upstream side often has striations, smoothed

Question 45

Describe isostacy

Answer 45

The crust floats on the mantle and the level it floats at depends on the weight of the crust

Question 46

how long ago was the last ice age

Answer 46

20,000 years ago

Question 47

What is isostatic rebound

Answer 47

as mass is removed through an ice sheet melting or erosion, continents float higher

Question 48

Are glaciers currently getting bigger or smaller

Answer 48

they are shrinking

Question 49

earths recent history has been characterized by cycles of ice ages and ______________ periods

Answer 49

interglacial

Question 50

what are the glacial - interglacial cycle controlled by

Answer 50

amount of solar radiation reaching different parts of the earth

Question 51

What are the three types of Milankovitch cycles

Answer 51

eccentricity, obliquity, and precession

Question 52

describe eccentricity

Answer 52

shape of the earth changes - less circular or more circular

Question 53

describe obliquity

Answer 53

angle of earths axis changes

Question 54

describe precession

Answer 54

wobbling of the earth axis changes

Question 55

Insolation cycle represents what?

Answer 55

the overall change of the earths cycle. addition of obliquity cycle, eccentricity cycle, and precession cycle. Describes energy reaching the earths surface

Question 56

What other two important graphs fluctuate at the same pattern as the insolation cycle does

Answer 56

the oxygen isotope records and the warming and cooling cycle

Question 57

What is the uplift weathering hypothesis

Answer 57

global rate of chemical weathering is dependent on availability of fresh rock

Question 58

what is orogenesis

Answer 58

mountain building

Question 59

As new ________-rich crust is exposed to weathering, atmospheric ____ is consumed and the climate cools

Answer 59

silicate CO2

Question 60

What is eustacy

Answer 60

related to the volume of water in the ocean. It is a worldwide change of sea level

Question 61

Cooler climate: more water stored as ice, sea levels ______ warmer climate: water melts from ice, and sea levels ______

Answer 61

drops rises

Question 62

What is thermohaline circulation

Answer 62

is id driven by temperature and salinity gradients and has big influence on global climate patterns

Question 63

is cold water or warm water denser

Answer 63

cold water

Question 64

is salt water or fresh water heavier

Answer 64

salt water

Question 65

What does ocean circulation do

Answer 65

transports heat around the ocean on a global scale. Patterns include vertical convection and horizontal movement

Question 66

formation of ice sheets in polar regions causes salinity _________ in polar ocean water

Answer 66

increase

Question 67

What is the younger dryas

Answer 67

a moment of rapid climate change, glaciers can back big

Question 68

What is the hypothesis of why the younger dryas occurred

Answer 68

large pulse of fresh water disrupted ocean currents and this cooled climate in the northern hemisphere for about 1000 years

Question 69

what is the polar vortex

Answer 69

a stream and circulation of cold air. it can change or head outwards from the poles when there is different air pressure and winds