Earths Structure And Atmosphere Flashcards
What happens at plate boundaries
- tsunamis
- earth quakes
- volcanoes
- mountains
What are the layers of the earth from out to in
- crust
- mantel
- core
Where do earthquakes come from
Tectonic plates rubbing against each other
Why do tectonic plates move
Convection current in the mantel caused by radioactive decay in the core
What causes convection currents in the mantel
Radioactive decay in the core
Why are earthquakes hard to predict
- lack of equipment
- dont know how big
- lots of small unnoticed earthquakes
- do not know how the mantel is moving
How has the earths atmosphere changed since it was first formed
- less carbon dioxide
- more oxygen
- more nitrogen
3 processes that release carbon dioxide
- burning fossil fuels
- decaying matter
- respiration of farm life
- deforestation
3 processes that take in carbon dioxide
- dissolve in ocean
- locked up in sedimentary rock
- locked up in fossil fuels
- locked up in plants
How did the earths atmosphere form
Gases released through volcanic eruption
How did the oceans form
Condensation of water vapour in the atmosphere
What are Wegner’s evidence for continental drift
- land bridge between south america and africa
- similar fossils
- similar plants
Why wasn’t Wegner’s theory accepted at the time
- lacked evidence
* other theories you can’t disprove (God)
What were the three phases of the evolution of the atmosphere
1) volcanoes gave out gases
2) green plants evolved and produced oxygen
3) ozone layer allows evolution of complex animals
Describe the evolution of the atmosphere
6 marks
- the earths surface was originally molten
- it cooled down creating a crust but volcanoes kept erupting which gave out gases
- water vapour condensed and formed oceans
- green plants and algae evolved
- early CO2 dissolved into oceans and was absorbed by plans through photosynthesis and locked up in sedimentary rocks
- the build up of oxygen killed some organisms but allowed others to evolve
- the oxygen created an ozone layer
