timeline

Question 1

100-50mya

Answer 1

Cretaceous period
- ‘green Antarctica’ separates from Pangea and starts to move south

Question 2

50mya

Answer 2

Paleocene/Ecocene thermal maximum
- no ice caps at poles
- Indian and Eurasian pates collide

Question 3

35mya

Answer 3

• opening of ocean between Tasmania and Antarctica

Question 4

30mya

Answer 4

• opening of the Drake passage
• formation of the Circumpolar current around Antarctica
• ice sheet forms

Question 5

20mya

Answer 5

• uplift of the Himalayas
• development of the Asian monsoon

Question 6

10mya

Answer 6

-further cooling from erosion of the Himalayas locking up carbon in deepsea sediments

Question 7

6mya

Answer 7

Messinian salinity crisis
- strait of Gibraltar closes
- Gulf stream slows down due to lack of saline input from the Mediterranean
- Atlantic much colder

Question 8

5.3mya

Answer 8

• Strait of Gibraltar reopens
• Gulf stream intensifies
• humidity in the North Atlantic increases
• Greenland ice cap forms

Question 9

4.5mya

Answer 9

• closing of Isthmus of Panama
• less input of Pacific water into Caribbean
• North Atlantic more saline
• Gulf stream intensifies
• Greenland ice sheet grows

Question 10

2.5mya

Answer 10

• start of Glacial-interglacial periods
• initiated by Milankovitch cycles

Question 11

800,000ya

Answer 11

Mid-Pleistocene transition
- 41,000yr glacial-interglacial cycle switches to 100,000yr cycle
- larger ice sheets mean more of a stimulus is needed to switch between glacial and interglacial, but they are more unstable, meaning the cycle is more intense and changes are more rapid

Question 12

21,000ya

Answer 12

• last ice age
• huge extent of ice caps
• sea level 120m lower

Question 13

10,000ya to now

Answer 13

• Holocene period
• unstable interglacial period

Question 14

7,000ya

Answer 14

• small rise in CO2 possibly linked to deforestation

Question 15

5,000ya

Answer 15

• small rise in methane possibly linked to the start of rice and cattle farming

Question 16

4,200ya

Answer 16

• cold arid event linked to collapse of many civilisations