Biogeochemical Cycles

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Biogeochemical Cycles
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3 Fundamental Laws of Nature

• Conservation of Matter
• 1st Law of Thermodynamics (Conservation of
  Energy)
• 2nd Law of Thermodynamics (Entropy)

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EarthMatter does not come and go
Earth is a Closed System to Matter
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Biogeochemical CyclesReservoirs Pathways
Atmosphere
Biosphere
Lithosphere
Hydrosphere
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Some Major Cycles of Matter

• Water Cycle
• Rock Cycle
• Chemical Cycles
• Carbon
• Nitrogen
• Phosphorous
• Sulfur

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Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere
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Carbon Cycle Reservoirs
Atmosphere
1x ( 7.3x1017 grams carbon)
Biosphere
3x
55x
35,000x
Lithosphere
Hydrosphere
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Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere
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Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere
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Carbon Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in Carbon in Atmosphere
Lithosphere
Hydrosphere
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Atmospheric Carbon Dioxide
northern winter
northern summer
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(No Transcript)
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Nitrogen Cycle
Atmosphere
Denitification bacteria
Biosphere

• Nitrogen fixation
• bacteria
• lightning

Absorption
Waste Decomposition
Erosion
Lithosphere
Hydrosphere
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Nitrogen-Fixing Bacteria in Root Nodules
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Nitrogen Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in Nitrogen in water soil

• Nitrogen fixation
• industrial (fertilizer)
• combustion

Increased Erosion
Lithosphere
Hydrosphere
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Phosphorous Cycle
Never enters the atmosphere
Atmosphere
Biosphere
Absorption
Waste Decomposition
Weathering Erosion
Lithosphere
Hydrosphere
Absorption
Sedimentation
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Phosphorous Cycle
Human Impacts
Biosphere
Net Effect Increase in phosphorous in water
algal blooms Depletion in soils
Mining, use (fertilizer, detergent, etc.)
increased runoff
Lithosphere
Hydrosphere
More Phos. for organisms
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Eutrophication
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ImpactRed Tide
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Sulfur Cycle
Bacteria Absorption
Atmosphere
Bacteria Release
Biosphere
Volcanoes Weathering
Absorption
Precipitation
Waste Decomposition
Weathering
Evaporation
Sedimentation
Lithosphere
Hydrosphere
Absorption
Deep Sea Vents
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Sulfur Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in atmosphere (health
effects) and acid rain
Precipitation Acid Rain
Burning Fossil Fuels
Lithosphere
Hydrosphere
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What is the ultimate interface of all 4
reservoirs for these cycles?
Soil