Topic 1: Tectonic Plates Flashcards
What is the structure of the earth?
Like an onion of 4 main layers
What theory did Alfred Wegener discover?
The Theroy of continental drift
What is the theory of the Continental drift?
How the earths continents have moved over geological time
What are some of the evidiences to support Alfred Wegner theroy?
The Jigsaw Fit
convection currents
Fossil theroy
palaeomagnetism
What is meant by the jigsaw fit?
All the continets fit like a jigsaw
What is meant by convection currents in Alfred Wegners theory?
There are convection currents in the mantle moving plates apart
What is meant by Fossil Theory in Alfred Wegners theory?
Similar fossils are found across different continents
What is meant by palaeomagnetism in Alfred Wegners Theory?
the study of magnetic rocks to record the history of the magnetic field.
What are the names of the major plate boundries?
Clue: Asian PE
African
South American
Indo-Australian
Antarctic
North American
Pacific
Eurasian
What are the two different tectonic plates?
Continental plates and oceanic plates
What are continental plates?
Continental plates are thicker, older and lighter, so they do not sink
What are oceanic plates?
Oceanic plates are thinner, younger, and denser so they can sink (subduct) under another plate.
What is a plate margin (boundary)?
the location where 2 tectonic plates meet or sit next to each other
What are the 3 different plate boundarys?
Conservative / transform
Constructive / divergent
Destructive / convergent
What movement occurs at a constructive plate boundary?
When two tectonic platers move away from each other
Where would you normally find a constructive plate boundry
Under the sea
What natural disaster happens at constructive plate boundarys?
Volcanoes and weak earthquakes
What movement occurs at a destructive plate boundary? (One oceanic plate and one continental plate)
Tectonic plates move toward each other and the oceanic subducts under the continental
What natural disaster happens at a destructive plate boundary? (One oceanic plate and one continental plate)
Intense volcanoes and earthquakes
What movement occurs at a destructive plate boundary? (Two continental plates)
Towards each other creating fold mountains due to the pressure