Ice Ages Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

True or false

We are still in an ice age?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an ice age?

A

A period of cooling, marked by the presence of glaciers and ice sheets, such as those currently found in Antarctica and Greenland .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the cold periods and warm periods of an ice age?

A

Cold-Glacial

Warm-Interglacial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many years has the earth been around for?

A

4.6 billion years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How major ice ages have their been ?

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The ________ Ice Age being the recent one and the period covers __ Million years of the earth’s history.

A

Quaternary

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What period is earth in at the moment?

A

Interglacial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Inter glacial period refers to the ______ in the longer period of glaciation known as the Quaternary Ice Age.

A

Interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many periods of cooling and subsequent glaciations have there been in the Quaternary Ice Age?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What was the most recent glaciation period?

A

Pleistocene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the climate like during a period of glaciation?

A

Cooler and drier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a glaciation?

A

A cold period marked by glacier and ice sheet cover.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The glaciation began _________,reached its peak _____ and was ended ________.

A

70000
20000
10000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is meant by the term Albedo?

A

The amount of reflectivity surfaces have

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Albedo for light and dark surfaces?

A

Light -high

Dark-low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How Ice ages begin?

A
  • As the climate cools at the start of glacial period, snow fallen in mountainous areas in winter will not melt completely in the following summer.
  • snow patches remain, this is then repeated over the years
  • glaciers will begin to develop in mountain valleys and on high land surface
  • If this continues, valley glaciers will extend into lowland areas and will eventually become large ice sheets covering vast areas of land
17
Q

What is a glacier?

A

A glacier is a persistent body of dense ice that is constantly moving under its own weight.

18
Q

How do glaciers form?

A

If forms where the accumulation of snow exceeds its ablation over many years,often centuries.

19
Q

During the Quaternary period ice-sheet growth must have occurred on many occasions. In the Northern Hemisphere, major ice sheets covered both _______ America and Northern _________. Smaller glaciers covered _______ and _______.

A

North
Europe
Britain
Iceland

20
Q

Sea levels dropped by 130m and the world’s land area increased by ____. America and ______ as well as Europe and _______.

A

8%
Asia
England

21
Q

What is the greenhouse effect?

A

The greenhouse effect is the process by which radiation from a planet’s atmosphere warms the planet’s surface to a temperature above what it would be without its atmosphere.

22
Q

Between the 15th and 19th centuries there was significant cooling in the northern hemisphere. The 20th century saw an ______ in temperature especially from 1990. The _______ effect on earth’s temperature is suspected of being responsible for this.

A

Increase

Greenhouse

23
Q

What causes Ice Ages?

A
  • Changes in the earth’s orbit
  • The tilt of the earth’s axis. Varies between 21.8 and 24.4
  • The Time Of year when the earth is closest to the sun.
24
Q

During an ice age ____ levels change substantially as can fall by as much as 130m.

A

Sea

25
Q

Where did land bridges develop?

A

Alaska and Siberia

Greenland and Canada

26
Q

Tropical areas would appear to have experienced dry periods during the glaciation in the northern hemisphere. The forests in these areas retreated and their place was taken by ________and open grasslands.

A

Savannah

27
Q

Our ape-like ancestors who lived in these forests had to compete with other forest dwellers for dwindling food supplies as caused by successive Ice ages. They thought to have abandoned the ______ and to have moved to more open Savannah and grasslands.

A

Forests