Topic 1: Earth, Sea and Atmosphere
- Created by: lois.michels
- Created on: 17-03-16 20:14
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- Topic 1: Earth, Sea and Atmosphere
- 1.4 Present Atmosphere
- The current composition of the atmosphere and proportions of gases has changed.
- Our atmosphere is currently 78% Nitrogen, 21% Oxygen, 0.9% Argon, 0.04% Carbon Dioxide, and traces of other gases.
- Changes in the atmosphere occur in lots of different ways.
- Volcanic Acitivty can produce a lot of Sulfur Dioxide.
- A lot of these changes are affected by human activity.
- The burning of fossil fuels increases amounts of Carbon Dioxide, Carbon Monoxide, and Sulfur Dioxide in the atmosphere.
- Farming cattle and rice fields releases large amounts of Methane.
- The deforestation of trees means that there are less trees to remove Carbon Dioxide.
- Engines and furnaces can release nitrogen oxides.
- The current composition of the atmosphere and proportions of gases has changed.
- 1.2 Changing Atmosphere
- Amounts of carbon dioxide decreased over time.
- This was because it dissolved into the oceans. Scientists believe about half of carbon dioxide was lost this way.
- This was then incorporated into carbonate rocks.
- Marine organisms used dissolved CO2 to make Calcium Carbonate shells. As these creatures died, their shells fell and became sediment. Over millions of years, this became sedimentary rock.
- Over time, amounts of oxygen increased and amounts of carbon dioxide decreased.
- Primitive plants developed the ability to photosynthesize, taking in the carbon dioxide and releasing oxygen.
- More photosynthesizing organisms evolved, increasig the rate at which carbon dioxide was removed and oxygen was added.
- Amounts of carbon dioxide decreased over time.
- 1.4 Present Atmosphere
- 1.1 Early Atmosphere
- Gases produced by volcanic activity formed the Earths early atmosphere.
- Topic 1: Earth, Sea and Atmosphere
- 1.4 Present Atmosphere
- The current composition of the atmosphere and proportions of gases has changed.
- Our atmosphere is currently 78% Nitrogen, 21% Oxygen, 0.9% Argon, 0.04% Carbon Dioxide, and traces of other gases.
- Changes in the atmosphere occur in lots of different ways.
- Volcanic Acitivty can produce a lot of Sulfur Dioxide.
- A lot of these changes are affected by human activity.
- The burning of fossil fuels increases amounts of Carbon Dioxide, Carbon Monoxide, and Sulfur Dioxide in the atmosphere.
- Farming cattle and rice fields releases large amounts of Methane.
- The deforestation of trees means that there are less trees to remove Carbon Dioxide.
- Engines and furnaces can release nitrogen oxides.
- The current composition of the atmosphere and proportions of gases has changed.
- 1.2 Changing Atmosphere
- Amounts of carbon dioxide decreased over time.
- This was because it dissolved into the oceans. Scientists believe about half of carbon dioxide was lost this way.
- This was then incorporated into carbonate rocks.
- Marine organisms used dissolved CO2 to make Calcium Carbonate shells. As these creatures died, their shells fell and became sediment. Over millions of years, this became sedimentary rock.
- Over time, amounts of oxygen increased and amounts of carbon dioxide decreased.
- Primitive plants developed the ability to photosynthesize, taking in the carbon dioxide and releasing oxygen.
- More photosynthesizing organisms evolved, increasig the rate at which carbon dioxide was removed and oxygen was added.
- Amounts of carbon dioxide decreased over time.
- 1.4 Present Atmosphere
- The early atmosphere contained:
- A large amount of carbon dioxide
- Water Vapour and small amounts of other gases.
- This water vapour, given out by volcanoes, condensed to make liquid water, which later condensed to make the oceans.
- Little or no oxygen
- There are different sources of infomation that make it difficult to be precise about the eveolution of the atmosphere.
- Some scientists think that most gases came from volcanic activity, however, they cannot be sure of how much these gases volcanic activity produced.
- The atmosphere of Titan is 98% nitrogen, which some scientists think was relased by volcanoes. They think the Earth's early atmosphere may have been like this.
- There are also volcanoes on Mars and Venus. Their atmospheres are mainly CO2. This led scientists to think the same about Earth.
- Titan has an icy interior rather than a rocky one, like Earth, Venus or Mars.
- This makes it more likely Earth's Early atmosphere resembles Mars or Venus.
- However, this does not explain how the Earth's atmosphere came to contain so much Nitrogen.
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