plates move due to varying convection currents in Earth in varying directions, plates always in relative motions (rigid lithospsher, crust created at mid ocean ridges and destryoed at subduction zones)
Interior of Earth
crust, mantle, outer core, innner core
gases part of nebular cloud that condensed to form solar system, gravity couldnt hold these gases closely around earth, first atmosphere lost
formed by volcanic outgassing, transferred volatile components from interior into earths atmosphere. mostly water vapor and carbon dioxide.
Present day volanic erruptions release...
water, c02, nitrogen, sulfur
todays atmosphere, large amount of water and c02 removed replaces by nitrogen and oxygen.
3rd atmosphere link to oceans (in respect to c02)
c02 dissolved in water to form calcium carbonate and and organic matter. burial of this organic matter and calcium carbonate drew down atmosphereic c02.
What does CaC03 and acid form
water +c02 +energy ---> organic matter and oxygen.
3 main gases in the atmosphere
nitrogen, oxygen, water
water vapor, methane, carbon dioxide, argon. keep earths climate from being unbearably cold
Troposphere "8 miles high"
most dynamic place in atmosphere. life lives, weather occurs (first layer of atmosphere) . temperature gets colder as you go up. 20 miles thick 32 km
Above troposphere. temperature go upward.
located in between troposphere and stratosphere
Why are poles cold and equator hot?
because of the angle the earth is at the equator gets more direct radiation
80 nitrogen 20 oxygen
Sea floor spreading
Harry Hess, mechanism for continental drift
seafloor spreading anomolies
humans appeared one second ago. (6-7 million years ago)
differential reproductive success
Atmosphere is comparable to
varnish on a globe. relativaly thin
No free oxygen until when
produces oxygen and draws down c02
burial of organic matter....
draws down atmospheric c02
burning of organic matter
raises atmosphere c02
Average insulation for Earths surface
342 watts per square meter