Glaciers

Question 1

Define glaciers

Answer 1

A glacier is a large, slow moving river of ice, formed from compacted layers of snow, that slowly deforms and flows in response to gravity.
Glacier ice is the largest reservoir of fresh water on Earth

Question 2

What are the 2 types of glaciers

Answer 2

Alpine and continental glaciers

Question 3

How does glacier ice form

Answer 3

As snow builds up the density increases and compacts more and more thus it forms into solid ice overtime.

Question 4

Define ice house

Answer 4

Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously.

Question 5

Define greenhouse worlds or

Answer 5

A “greenhouse Earth” is a period during which no continental glaciers exist anywhere on the planet.[6] Additionally, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions

Question 6

Explain the movement of glacial ice

Answer 6

Its called plastic flow.
The lower layers of glacial ice flow and
deform plastically under intense pressure,
allowing the glacier as a whole to move
slowly like a viscous fluid. Similar to ductile flow

Question 7

What does inclusions in respect too course grained ice allow us to understand in respect to understanding the past.

Answer 7

By analyzing ice cores, you can see inclusions of water, oxygen and this can be show the amount of the C02 in the atmosphere when that Ice formed.

Question 8

Define crevasses

Answer 8

Uppermost levels of glacier 
(about 50 m) ice forms 
crevasses (rigid or brittle zone) 
• Brittle behaviour
• Below brittle-plastic transition 
zone ice is able to flow or 
deform plastically (zone of 
plastic flow)
• Analogous to brittle and ductile 
deformation of rocks

Question 9

Define Glacial budget

Answer 9

In order to have glaciers the accumulation zone has to be dominant, the ablation zone will be dominate in lower region, a
Ablation refers to melting, runoff, evaporation or sublimation (transformation from solid to gaseous state) of ice resulting in a thinning of the ice if it is not replenished by some other process

Question 10

Define Albedo

Answer 10

the ability to reflect sunlight; ice and snow reflect light/heat; can cause ice sheets to grow

Question 11

Define an Alpine (Mountain) Glaciers

Answer 11

Form in mountainous regions; topography controls shape and flow direction
Occur at all latitudes (but at much higher altitudes closer to the equator)

Question 12

How do glaciers effect landscape considering Alpine glaciers

Answer 12

the creation of U-shaped valley. Glacier melts and flows carve out and eroded the landscape drastically.

Question 13

Define continental glaciers

Answer 13

Much larger than valley glaciers - spread over continental crust. 
------Greenland and Antarctica
Lens shaped (thickest in the middle). 
They flow out in all directions 
More than 50,000 km squared in extent

Question 14

Define the ice ages of the Pleistocene epoch

Answer 14

The pleistocene epoch had times when glaciers retreated (interglacials) because of mild temperatures and advanced because of colder temperatures (glacial)

Question 15

Know about the holocene and interglacials** test question

Answer 15

Currently, in the holocene, the last glacial maximum to occur was 18,000 years ago

Question 16

What was the last glacial ion period called

Answer 16

Wisconsin glasiaction

Question 17

Define surficial deposits

Answer 17

Inter-layered glacial deposits and soil layers

Question 18

Why are interglacial deposits thin

Answer 18

The soil and rocks get eroded away during glacial periods

Question 19

What occurred when there was 3-4km of ice sheets in North America

Answer 19

Sea levels dropped by 120 meters

Question 20

Define erratics

Answer 20

One of the deposits by glaciers. They are exceptionally large rocks carried a long distance by glaciers.

Question 21

What is evidence for glaciers from oceans

Answer 21

Different microfossils in soil deposition will be there based off warm or cold water

Question 22

What kind of world do we live in

Answer 22

Icehouse world, as the North and south poles are sheets of ice

Question 23

Why would the east coast be damaged more by sea level rise than the west coast

Answer 23

The east coast is a passive margin while the west coast is a tectonic boundary that causes uplift

Question 24

Define glacial abrasions and striations

Answer 24

Abrasions occur when the ice and the load of rock fragments slide over the bedrock. Come back to this

Question 25

What kind of world was it in the Devonian

Answer 25

Greenhouse world

Question 26

What kind of world was it during the late Carboniferous and early Permian

Answer 26

Icehouse world in the Southern Hemisphere

Question 27

Define milankowitch cycles

Answer 27

A series of changes to the Earth’s orbit which can fluctuate climate.
Short-term causes of glacial fluctuations are attributed to the cycles in the Earth’s rotational–axis and to variations in the earth’s orbit around the Sun which affect the distance between Earth and the Sun

Question 28

What kind of earth was it during the late Cretaceous

Answer 28

Greenhouse earth