Ice Levels Over Time

Question 1

What type of periods does the earth have?

Answer 1

Glacial.

Interglacial.

Question 2

The earth goes through cold periods, how long do these last?

Answer 2

Millions of years.

Called ice ages.

Question 3

What happens during ice ages?

Answer 3

Large masses of ice cover parts of the Earth’s surface.

Question 4

What and when was the last ice age?

Answer 4

The Pleistocene.

Began around 2.6 million years ago.

Question 5

During ice ages what are the cooler periods called?

Answer 5

Glacial periods.

Question 6

What happens during glacial periods?

Answer 6

Ice advances to cover more of the Earth’s surface.

Each one lasts about 100,000 years.

Question 7

In between glacial periods there are what?

Answer 7

Warmer periods called interglacial periods.

Question 8

What happens during interglacial periods?

Answer 8

Ice retreats to cover less of the Earth’s surface.

Each one lasts about 10,000 years.

Question 9

When did the last glacial period begin and end?

Answer 9

Began - 100,000 years ago.

Ended - 10,000 years ago.

Question 10

When did ice cover much more of the earths surface?

Answer 10

20,000 years ago.

Question 11

Since the beginning of the pleistocene what has there been?

Answer 11

Permanent ice sheets on Greenland and Antarctica.

Question 12

What % of land was covered in ice during the last glacial period?

Answer 12

30%.

Question 13

What are we currently in?

Answer 13

An interglacial period that begun 10,000 years ago.

Question 14

Today how much of the earths surface is covered in ice?

Answer 14

10%.

Question 15

What are ice sheets?

Answer 15

Huge masses of ice that cover whole continents.

Question 16

What are glaciers?

Answer 16

Masses of ice which fill valleys and hollows.

Question 17

Evidence of changing temperature comes from where?

Answer 17

Three main sources.

Question 18

What are the 3 main sources changing temperatures comes from?

Answer 18

Chemical.
Geological.
Fossil evidence.

Question 19

Chemically what changes as temperature changes?

Answer 19

Chemical composition of ice.

Marine sediments.

Question 20

Why does chemical composition of ice and marine sediments change as temperature changes?

Answer 20

So they can be used to work out how global temperature has changed in the past.

Question 21

Ice and sediments build up over thousands of years, so what is taken?

Answer 21

Samples taken at different depths show the temperature over thousands of years.

Question 22

Some landforms we see today were created by what?

Answer 22

Glaciers in the past.

Question 23

Some areas that aren’t covered in ice today were covered in ice in the past, what does this mean?

Answer 23

Temperatures were lower.

Question 24

The remains of some organisms are persevered when they die, what does this create?

Answer 24

Fossils.

Question 25

What do fossils show?

Answer 25

The distribution of plants and animals that are adapted to warm or cold climates at different times in the past.