The Water Abd Carbon Cycles

Question 1

What type of systems are the global water and carbon cycles

And what are the time scales

Answer 1

Closed systems

Flow between atmosphere, ocean, land and biosphere

The cycling of individual water molecules and carbon atoms occurs on time scales varying from dye to millions of years

Question 2

At a macro-scale the global water cycle consists of 3 main stores…

Answer 2

Atmosphere: 13 thousand cubic kilometres

Oceans: 1,370,000 thousand cubic kilometres

Land: 39,000 thousand cubic kilometres

Oceans largest store, atmosphere smallest store

Question 3

How does water move from store to store

Answer 3

Precipitation
Evapotranspiration
Run-off
Groundwater flow

Question 4

What is the largest long-term store of carbon

Answer 4

Sedimentary rock holds 99.9% of all carbon on earth

Question 5

How does carbon flow around the cycle

Answer 5

Most of carbon in circulation moves rapidly between the atmosphere, the oceans, soil and biosphere

Main pathways: photosynthesis, respiration, oxidation (decomposition and combustion) and weathering

Question 6

The water and carbon cycles as open and closed systems

Answer 6

Systems are groups of objects and the relationships that bind the objects together

On a global scale the water and carbon cycles are closed systems driven by the suns energy. Only energy cross the boundaries of the global water and carbon cycles- “closed system”

At smaller scales (eg drainage basins or forest ecosystems) materials as well as the suns energy cross system boundaries. These systems are therefore open systems