What three pieces of evidence did Wegener give for his theory?
All the continents fit like a jigsaw, mountain ranges and rock patterns match up and there were fossils of the same animals on different continents.
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Four reasons why scientists did not believe Wegeners theory?
He wasn't a geologist, the supporting evidence was limited, It could be explained more simple by a land bridge, There was no mechanism.
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How did Wegeners theory become accepted?
Evidence from seafloor spreading convinced the scientists and through peer review it became accepted.
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How does seafloor spreading occur?
The mantle is solid at the top but at the bottom is liquid, Currents in the mantle cause magma to rise. The magma moves the mantle and tectonic plates. Where plates are moving apart magma reaches the surface and hardens creating new sea floor
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What is subduction?
When a denser plate is forced under a less dense tectonic plate
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What are earthquake waves detected on?
A seismograph
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The two types of wave are...
Primary and secondary
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The properties of P-waves?
-Travel faster than S -Travel through liquids and solids - Can travel through the liquid region of the outer core of the earth
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The properties of S-waves?
-Can only travel through solids -Can't travel through the liquid region of the outer core of the earth
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Transverse waves?
They look like a wave in water and are p-waves
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Longitudinal waves?
The are like when a slinky is compressed and retracted. They are s-waves.
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How do waves help find out the structure of the earth?
As p-waves can travel through liquids but s-waves cannot, scientist detect if the waves can both go through or if just the p-wave can. This is how they find if part of the earth is solid or liquid.
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What kind of wave does sound travel in?
Longitudinal
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What kind of wave does light and water travel in?
Transverse
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What is amplitude?
From the crest of the wave (top) to the middle
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What is wavelength?
The width of one of the waves
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What is frequency?
The number of waves produced in one second.
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What do you measure frequency in?
Hertz
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The equation for the speed of a wave?
Wave speed = Frequency x Wavelength
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About how long ago was the solar system formed?
5000 million years
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What happened in the theory of the big bang?
Dust, gas and clouds were pulled together by gravity, This created tense heat and nuclear fusion began and the sun was born. Remaining dust and gas formed smaller masses which were attracted to the sun
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What is nuclear fusion?
Hydrogen atoms fuse together to produce an atom with a larger mass and binding energy stored in the hydrogen atoms is released.
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What is light pollution?
When electric lights on earth make it difficult to see stars
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The order of the planets away from the sun?
The sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
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Other cards in this set
Card 2
Front
Which of the cores in the earth is liquid?
Back
The outer core.
Card 3
Front
What is Wegener's theory?
Back
Card 4
Front
What three pieces of evidence did Wegener give for his theory?
Back
Card 5
Front
Four reasons why scientists did not believe Wegeners theory?
These flashcards are really good, however, i noticed that some of your flashcards are incorrect. For example, s-waves are transverse and p-waves are longitudinal, you however put them the wrong way round. So i think you should check your flashcards so other people do not get the questions wrong in an exam.
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