7 - The Ever Changing Earth

Question 1

What evidence is there to support Alfred Wegner’s theory?

Answer 1

• same types of fossilised animals were found in South America and Africa
• the shape of the East Coast of South America fits the West Coast of Africa like a puzzle

Question 2

Why did other scientists disagree with Alfred Wegner?

Answer 2

• he was trained as an astronomer and they didn’t think he had the right background to judge geological theories
• he couldn’t explain how

Question 3

How do tectonic plates move?

Answer 3

-convection currents in the mantle caused by the heat released by radioactivity in earth’s core causes the plates to move

Question 4

What gases does the Earth consist of today?

Answer 4

-mainly nitrogen and oxygen but also gases like carbon dioxide

Question 5

How do carbon dioxide and oxygen levels remain constant with natural processes?

Answer 5

• photosynthesis and respiration
• combustion
• deforestation keeps the Co2 and removes the o2 from reduced number of plants

Question 6

What are some consequences of global warming?

Answer 6

• extreme weathers
• ice caps melt
• destroys habitats
• flooding

Question 7

Yearly changes of co2 variations?

Answer 7

• less released in the summer as less fuels are burnt to heat homes
• less CO2 released in power stations as days are longer in the summer so less electricity needed for lighting

Question 8

What is Alfred Wegner’s theory on continental drift?

Answer 8

-continents were once all joined but gradually moved apart (Pangea)

Question 9

What were the main gases in the Earth’s early atmosphere?

Answer 9

Water and carbon dioxide

Question 10

What were the main gases in the Earth’s early atmosphere?

Answer 10

Water and carbon dioxide