L1 - Glacier Formation

Question 1

How do glaciers form?

Answer 1

Via compaction of snow flakes and the removal of air bubbles which leads to granular snow then firn and then glacier ice

Question 2

What is defined as glacier ice?

Answer 2

Ice that has survived more than one season

Question 3

What 2 factors influence the survival of snow over the summer season?

Answer 3

1. The Angle of the Sun

2. Climate

Question 4

What influences the formation of tropical glaciers?

Answer 4

Lapse Rates (Elevation and Temperature)

Question 5

What are the 2 controls on glacier formation?

Answer 5

1. Topography

2. Hydrology

Question 6

Name 5 types of glaciers that are constrained by topography?

Answer 6

1. Cirque
2. Valley
3. Tidewater
4. Piedmont
5. Hanging Glacier

Question 7

What are the 2 main types of glaciers that are unconstrained by topography?

Answer 7

1. Ice Sheet

2. Ice Cap

Question 8

What is the difference between an ice sheet and an ice cap?

Answer 8

An ice sheet covers almost 100% of the land whereas an ice cap doesn’t and tends to be

Question 9

Name 2 locations where ice shelves are common?

Answer 9

1. Canadian Arctic

2. Larsen, Antarctica

Question 10

Where has most research been done?

Answer 10

On mountain glaciers

Question 11

Which glacier accounts for the most of the global coverage?

Answer 11

Antarctica

Question 12

What is the current concern regarding glaciers?

Answer 12

There is an acceleration in worldwide retreat

Question 13

What have the valleys under the AIS been compared to with regards to their size?

Answer 13

The Grand Canyon

Question 14

Underneath the Greenland Ice Sheet a trough has recently been discovered, what has its depth been compared to?

Answer 14

The height of the Eiffel Tower

Question 15

Name 2 Paleo Ice Sheets

Answer 15

1. British Irish

2. Laurentide

Question 16

Name 4 reasons why glaciers are important

Answer 16

1. Water Resources
2. Hazards
3. Sea Level Rise
4. Climate Feedback

Question 17

Name 2 locations where glacier outburst floods are common

Answer 17

1. Iceland

2. Nepal

Question 18

What does GLOF stand for?

Answer 18

Glacial Lake Outburst Flood

Question 19

If you were to melt all of the worlds glaciers what level sea level rise would this equate to?

Answer 19

~80m

Question 20

What are the 4 types of Glacier related Sea Level Change?

Answer 20

1. Glacioeustasy
2. Glacioisostasy
3. Geodial Isostasy
4. Steric Sea Level Change

Question 21

What is Glacioeustasy?

Answer 21

When glaciers lock up water from the water cycle

Question 22

What is Glacioisostasy?

Answer 22

When the Earth’s crust is depressed by the weight of the ice sheets – it rebounds following the LGM

Question 23

What is Geodial Isostasy?

Answer 23

Ice sheet mass can cause changes in the Earth’s gravitational field

Question 24

What is Steric Sea Level Change?

Answer 24

Decreases in water density and increases in temperature can cause expansion of the oceans above 4DegC

Question 25

What is the Ice Albedo Feedback?

Answer 25

Ice sheets have a high albedo –> this means that they have high reflectivity –> this means less radiation is absorbed –> this leads to localised cooling