the physical environment an integrated system of four spheres
TRANSCRIPT
The Physical Environment
An integrated system of four spheres
What are the four spheres?
• Atmosphere– Trophosphere 0-10 miles
• Virtually all water here
• Ozone layer here
• 80-85% of mass of atmosphere
– Stratosphere 10-30 miles– Mesosphere 30-50 miles– Thermosphere >50 miles
• Little known
• Except for water and ozone, composition is fairly constant up to the thermosphere
• Density goes down as you go up
Lithosphere
• Geology
• Crust of earth
Hydrosphere
• Water layer on earth
• Carries heat, moves it pole-equator and vice versa
• Influenced by the Coriolis effect
Biosphere
• Layer where life is
• Deepest ocean - highest mountain tops
• Next week we’ll look at various biomes (specific divisions of biosphere)
• Ecology applies here
Cycles Between the Spheres
• Law of Conservation of Energy - matter cannot be created nor destroyed
• Matter and energy can be transformed into various forms
• Gas-liquid-solid
• Biogeochemical cycles
Abundances
• Life is very different from its environment
Carbon Cycle
• Looks complex; but it is all about withdrawals to and additions from atmosphere
• Withdrawls:– Photosynthesis– 6CO2 + 6H20 + energy ---->C6H12O6 + 6O2– Accumulation into tissues
• Fossil fuels
• Shells = limestone
Oceanic
geological
TerrestrialAtmosphere
Carbon Cycle
• Additions:– Cellular respiration– C6H12O6 + 6O2 ---> 6CO2 + 6H2O + energy– Literally exhalation– Combustion
• Of such fossil fuels
• Global warming = too much CO2 accumulating in atmosphere
Carbon cycles goes through all 4 spheres
• Atmosphere - CO2 gas
• Hydrosphere - CO2 gas, also in tissues
• Now in Biosphere
• When organisms die now tissues become fossilized; part of lithosphere
• Fossil fuels burned releases CO2 gas back to atmosphere