Environments

Question 1

Where are cold environments found?

Answer 1

High latitudes and high altitudes. E.g. Arctic and Antarctic circles and lower latitudes but high altitudes like the Himalayas

Question 2

3 types of cold environments:

Answer 2

Glacial - permanently below 0°c

Peri-glacial - on the edge of glacial environments with a bit of melting and thawing in summer. Only found in northern hemisphere because of greater landmass at high latitude.

Alpine - mountainous areas with snow and ice in winter and lots of melting and thawing in summer. (Alps)

Question 3

Ice age definition

Answer 3

When a significant proportion of the earths surface is covered in ice

Question 4

Inter glacial and stadial periods

Answer 4

Inter glacial periods are the warmer periods of an ice age and within them you get stadials such as the little ice age (1515-1815)

Question 5

Glacial and inter-stadial periods

Answer 5

Glacial periods are the colder periods and within these, there are inter stadials which are warmer sub-periods.

Question 6

Quaternary ice age

Answer 6

We are in the quaternary ice age now and there have been two main periods:
Pleistocene - 1.8 million years ago - 10,000 years ago
Holocene - 10,000 years ago - now

Question 7

How do we know that climate has changed? (7 ways)

Answer 7

Church records
Carbon dating
Sea floor analysis
Ice core analysis
Tree rings
Fossil remains
Landscapes

Question 8

Sea floor analysis explanation and method

Answer 8

The ocean contains isotopes of oxygen, O16 and O18.
O16 evaporates more easily and returns to the ocean as precipitation, thus keeping the ratio constant.
However in cold periods, it remains on the land as snow or ice thus changing the ratio.
Clean creatures make their shells out of oxygen so in colder periods, their shells contain more O18.
These shells become sedimentary rock which can be analysed.

Question 9

How landscapes show climate has changed

Answer 9

Landforms such as drumlins and moraines indicate ice cover and direction of flow in the past

Question 10

How does ice core analysis show that climate has changed?

Answer 10

Ice cores can be drilled in Antarctica and oxygen ratios can be measured in similar ways to sea floor. This provides accurate information about previous climates

Question 11

how does carbon dating show that climate has changed?

Answer 11

Organic matter contains equal isotopes of C12 and C14.
C14 decays and C12 doesn’t.
By measuring the ratios of Carbon isotopes, you can tell how long the organism has been dead for.
You can take an educated guess for what the climate was like by looking at characteristics of the organism

Question 12

How can tree ring analysis show that climate has changed?

Answer 12

The wider the tree ring, the warmer and more humid the climate was.
This indicated which years were warmer and colder.
Only max 4,000 years and doesn’t give exact temperatures.

Question 13

How can fossil remains show that climate has changed?

Answer 13

Tells us about the type of animal in particular places and can indicate a climate at that time.

Question 14

Milankovich cycles

Answer 14

Eccentricity - orbit shape - 100,000 years with a sub cycle of 40,000 years

Obliquity- axial tilt - 41,000 years

Precession - wobble of the axis - 26,000 years

Question 15

Why has climate changed? (6 reasons)

Answer 15

Milankovich cycles
Sunspot activity
Volcanic activity
Landmass changes
(Current global warming)

Question 16

Why has sunspot activity caused climate to change?

Answer 16

The sun flares up in parts generating more heat and reduction of sunspots leads us into a colder period (little ice age)
Tends not to give more than 2°c difference

Question 17

Why do volcanic events cause climate change?

Answer 17

Ash rises up into the atmosphere and circulates round the globe and acts like a sheet blocking out the sun and cooling the environment

Question 18

Why do landmass changes cause climate change?

Answer 18

A large land mass surrounded by one ocean can retain heat better than lots of smaller land masses because land is warmed quicker by the sun

Question 19

Effects of he little ice age (1550-1850)

Answer 19

Bought colder winters - canals and rivers froze (Thames)
Glaciers advanced and wiped out villages in the alps
Sea ice extended out from Iceland
Greenland was cut off due to ice
Crops were destroyed

Question 20

Scale and location of ice

Answer 20

Ice sheets- vast expanses of ice, over 1km thick.
Ice caps- smaller masses of ice often associated with mountain ranges.
Ice fields- areas less than 50,000 square km.
Glaciers

Question 21

Types of ice flow

Answer 21

Basal flows:
Extending
Compressing
Surges
Creep
Rotational

Non basal flow:
Internal

Question 22

Compressing flow

Answer 22

Occurs when gradient is low
Speed of ice decreases and ice thickens
Erosion is high

Question 23

Extending flow

Answer 23

Occurs when the gradient is steep
Ice moves faster and thins
Erosion is less here

Question 24

Surges

Answer 24

When a glacier moves very rapidly (up to 100 times faster than usual)
Due to excess meltwater

Question 25

Creep

Answer 25

When ice meets an obstacle, it becomes pressurised and behaves like a plastic and flows around the obstacle.
Then it returns to normal flow

Question 26

Rotational flow

Answer 26

When ice pivots around a central point in a rock basin, widening and deepening it.

Question 27

Internal flow (deformation)

Answer 27

This happens in both temperate and polar glaciers.
Ice crystals deform to become streamlined in the direction of flow.
They slip and slide past each other very slowly.

Question 28

Basal flow

Answer 28

Where meltwater, resulting from pressure and friction, allows ice to move more rapidly.
Only happens in temperate/alpine glaciers.

Question 29

Where is the fastest flow in a glacier?

Answer 29

Centre (looking from above)

Top (looking from the side)

Question 30

Formation of ice

Answer 30

As snow falls, it compacts to form ice in a process called alimentation.
Over time, oxygen it squeezed out to give it a blue colour.
Known as firn or névé.

Question 31

Snow lines

Answer 31

Can only happen at the equator at 6,000m and is symmetrical.
In the northern hemisphere, the snow line is north facing.
In the Southern Hemisphere, the snow line is south facing.

Question 32

Types of glacier (temperate/alpine)

Answer 32

E.g. In the Alps
They melt in the summer and the meltwater acts as a lubricant and reduces friction.
Erosion, transportation and friction occur

Question 33

Types of glacier (polar)

Answer 33

These occur when the temperature is permanently below 0°c.
Therefore NO melting occurs.
They are frozen to heir beds and movement is internal and slow.

Question 34

Pressure melting point

Answer 34

Usually is similar to the temperature of the base so melting occurs.
But the temperature of the base of a polar glacier is much colder so NO melting occurs ever.

Question 35

Positive and negative feedback

Answer 35

Negative feedback happens to keep a system stable in equilibrium.
E.g. More snowfall —> more ablation (melting).

Positive feedback exacerbates the change.
E.g. Environment cold so more snow, more of the suns energy reflected (albedo) so it gets colder…