EQ1 Flashcards
What is the biological carbon cycle?
‘Fast carbon cycle’ concerned with biomass, and the atmosphere
What is the geological carbon cycle?
‘slow carbon cycle’ concerned with rocks, sediment, and hydrology
What are the three main stores of lithospheric carbon within the geological cycle?
Limestone - comprised of ancient dead organisms from 1000-500 years old.
Coal - Peat bog biomass which as been compressed to change its chemical composition.
Shale - Comrpessed dead organisms become shale layers within rock.
What are the main tranfers (fluxes) within the geological carbon cycle?
weathering processes
volcanic outgassing - releases 0.25 - 15 Gigatonnes of carbon into the atmosphere annually.
What are the three main weathering processes?
Mechanical weathering - Freeze-thaw weathering
Biological weathering - roots and burrowing animals
Chemical weathering - Acid rain.
What are the key stages of negative feedback concerning the geological carbon cycle?
- Increased volcanic activity
- loss of carbon in rock
- rising temeprature fom CO2
- more air uplift
- more chemical wethering
- more ion decomposition
- mroe carbon in rocks.
What are the three ways in which the biological carbon cycle sequesters carbon in oceans?
The biological pump
The carbonate pump
the physical pump
What is the process of the biological pump?
- Phytoplankton photosynthesise
- Phytoplankton are eaten by zooplankton
- Zooplankton are eaten by bigger animals, and are then sequestered as marine snow.
- marine snow then floats to deeper ocean
What is the process of the carbonate pump?
Phytoplankton proguce inorganic carbon in the form of shells. This then sinks when the creature dies to the bottom of the ocean.
What is the process of the physical pump?
Warm water cools because of thermohaline circulation, and absorbs CO2.
This then allows the water to sink and also sink the CO2 it has absorbed.
What are the Himalayas made of and why?
Limestone from ancient sequestration of marine organisms.
What is the overall process of the slow carbon cycle?
- Terrestrial carbon exists in mantle
- Volcanos release CO2 into the atmosphere through outgassing.
- Acid rain /carbonic acid weathers sediment.
- rivers transport newly carbonated sediment to the ocean, and forms a new layer of sediment.
- subduction then causes carbon to return to the mantle, while releasing CO2 in the process.
What is the process of thermoline circulation?
- Polar ocean - cold sinking water
- travels to arctic to recharge into cold, salty water.
- travels towards the equator and heats up and rises.
- travels along globsl currents before reaching the arctic again.
(This process takes 1000 years)
What factors influence the speed of decomposers?
- climate - high temp. = fast
- pH in soil = slightly acid to neutral pH
- human activity = ploughing = good.
What are the largest global stores of terrestrial carbon?
The rainforest = biomass
boreal forest = humus