Biosphere- Biogeochemistry

Question 1

What is silicate weathering

Answer 1

The slow weathering of the earths crust

Question 2

There is a large imbalance between oxygen and carbon in the atmosphere, more oxygen than carbon, why is this?

Answer 2

This is due to carbon being buried in the sea bed/lithosphere and not in the atmosphere

Question 3

We are now extracting and burning fossil fuels which is increasing long term carbon release by how much

Answer 3

100X

Question 4

How did burial of organic matter allow oxygen in the atmosphere and therefore life to form

Answer 4

Without burial, decomposition would have released almost all carbon as CO2 and consumed all the oxygen in the atmosphere so oxygen levels wouldn’t have built up to make complex life possible

Question 5

What percentage of the atmosphere does nitrogen make up?

Answer 5

78%

Question 6

Key biological processes in the nitrogen cycle

Answer 6

Nitrogen fixation
Mineralisation
Nitrification
Denitrification (output)

Question 7

How are humans having a major impact on the nitrogen cycle

Answer 7

Fertilisers

Question 8

Is there a +ve or -ve relationship between nitrogen deposition and plant growth

Answer 8

+ve (nitrogen fertilisation)

Question 9

What happens to gas solubility as temperature increases and what are the implications of this

Answer 9

It decreases, meaning oceans can take up less CO2 from the atmosphere (marine sink slowing down)