10 Glaciation

Question 1

Epoch

Answer 1

Subdivision of a geological period ranging from 1-10mil years

Question 2

Cold periods of temp variations were called…

Answer 2

Glacials

Question 3

Warm periods of temp variations were called…

Answer 3

Interglacials

Question 4

Nunatak definition

Answer 4

Part of the landscape protruding above ice cover

Question 5

Terminal Moraine definition

Answer 5

Material deposited in front of the ice sheets when the ice had reached its maximum advance

Question 6

Glacial ice formation:
Ice advance-ice retreat

Answer 6

snow accumulates
weight compresses air from underlying layers into
1.granular ice
2.firn
3.glacial ice.
Low air concentration=bluer ice

Question 7

Where can valley glaciers b found

Answer 7

The Alps

Question 8

Where can ice sheets be found

Answer 8

Greenland

Question 9

What is glacier mass balance

Answer 9

Difference between the amount of ice a glacier gains in winter and loses in summer

Question 10

Explaine positive mass balance

Answer 10

Glacier gains more ice in winter than it loses in summer = advancing

Question 11

Explain negative mass balance

Answer 11

Glacier loses more ice and is retreating

Question 12

What dors it mean when a glacier is labeled as “stationary”

Answer 12

When loss and gain of ice are balanced

Question 13

What are the two zones glaciers have called?

Answer 13

Accumulation zone
Ablation zone

Question 14

What is the accumulation zone of a glacier?

Answer 14

Snow falls and remains all year here

Question 15

What is the ablation zone of a glacier?

Answer 15

Winter snow melts during the summer here

Question 16

What divides the accumulation and ablation zones of a glacier

Answer 16

Snowline

Question 17

Define ablation

Answer 17

Loss of ice and snow from a glacier by melting,runoff and evaporation

Question 18

Name three ice flow processes

Answer 18

1.Basal Sliding
2.Plastic Flow/Internal Flow
3.Rate of flow

Question 19

Explain 1.Basal Sliding

Answer 19

At base of glacier friction from heavy ice on bedrock causes melting.
Meltwater acts as lubricant and causes glacier to move downhill
Rate of this will depend on steepness of glacier and rate of ice accumulation

Question 20

Explain 2.Plastic flow/Internal flow

Answer 20

2 zones WITHIN a glacier
Upper zone:Ice brittle. breaks easily to form crevasses
Lower zone: ice under steady pressure=stronger wnd able to bend without breaking

Question 21

Explain 3.Rate of flow

Answer 21

Friction with bedrock and valley sides means rate of flow at base and sides is much slower than at surface(middle)
In middle surface glacier ice flows faster

Question 22

name 3 forms of glacial erosion

Answer 22

1.Plucking
2.Abrasion
3.Freeze-thaw action

Question 23

Explain 1.Plucking

Answer 23

Plucking is when glacier ice melts and seeps around a rock, refreezes and carries the rock with the glacier as the glacier moves

Question 24

Explain 2.Abrasion

Answer 24

The rock particles on the base of the glacier abrade the rock underneath the glacier leaving marks called STRIAE on the rock.

Question 25

Explain 3.Freeze thaw action

Answer 25

When water seeps into cracks in the rock and refreezes it expands and can break off rock around the crack called scree

Question 26

Name the two types of glaciation

Answer 26

1.Upland Glaciation (alpine) 2.Lowland Glaciation (continental)

Question 27

What is Upland Glaciation

Answer 27

Mountainous regions Carried out by glaciers Mostly landforms of erosion Alps/Himalayas/Kerry

Question 28

What is Lowland Glaciation

Answer 28

Carried out by ice sheets Mostly landforms of deposition Greenland/Kildare/Offaly

Question 29

What is the rate of glacial erosion influenced by

Answer 29

Presence/absence of well jointed bedrock Gradient (steeper=faster erosion overall) Shape Size and amount of Basal Debris

Question 30

Describe a cirque

Answer 30

Armchair shaped depression that forms on slopes of upland areas

Question 31

Describe an Arête

Answer 31

2cirques form back to back creating a narrow ridge in the middle called an arete

Question 32

Describe a pyramidal peak

Answer 32

Angular pointed mountain peak

Question 33

describe a U shaped valley

Answer 33

Valley with steep sides and a broad flat floor

Question 34

Describe pater noster lakes

Answer 34

Series of glacial lakes connected by streams