earths atmosphere

earths atmosphere

for 200million years, the atmosphere has been how it is now
1. 78% nitrogen
2. 21% oxygen
3. small amount other gases such carbon dioxide, water vapour and noble gases
phases of atmospheres evolution
1. phase 1- vocanoes gave out gas
  1. earths atmosphere was orignally molten. too hot for any atmosphere
  2. eventually it cooled down and a thin crust formed however volcanoes continued to erupt
  3. the volcanoes gave out a lot of gases which formed the oceans and atmosphere
  4. the earths atmosphere was most carbon dioxide. with basically no oxygen and small amounts of other gases such as water vapour.
  5. the ocean formed when the water vapour dissolved
2. phase 2- grean plants evoved and and produced oxygen
  1. green plants and algae evolved over most of the earth in the carbon dioxide atmospehere
  2. alot of the carbon dioxide dissolved into the oceans and was replaced by oxygen through photosynthesis
  3. plants and algae died and were burned under layers of segement with the skeletons and shells of marine organisms that had slowly evolved
    1. the carbon and hydrocarbons inside them had become locked up in sedimentary rocks as insoluble carbonates and fossil fuels.
      1. carbon is released into the atmosphere when fossil fuels are burnt, which rises the carbon dioxide concentration in the atmosphere.
3. phase 3- ozone layer allows evolution of complex animals
  1. the build up of oxygen killed off some organisms that couldn't tolerate it. but allowed some organisms to evolve and flourish
  2. the oxygen created the ozone layer,, which blocks harmful rays from the sun and allowed some organisms to evolve
  3. there is virtually no carbon dioxide left now
primordial soup
1. states that billions of years ago, earth atmosphere was rich in nitrogen, hydrogen, ammonia and methane.
2. lightening struck, causing a chemical reaction between the gases, resulting in the formation of amino acids
3. the acid was collected in a prmordial soup
  1. a body of water where life gradually crawled.
4. the amino acids gradually combined to produce organic matter, which eventually evolved into simple living organisms
5. reasearch shows that when gases are sealed them heated and electrical charge is applied for a week, amino acids are made
  1. not enough amino acid is made to prove the theory completely right
the earths atmosphere has all the resources humans need.

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	Criado por nafe mars quase 10 anos atrás