Layers of the Earth
Plate Tectonics Theories and Scientists
Plate Boundaries
Plate Boundaries II
100
What layer of Earth is the Crust?
Outside!
100
What is Pangaea?
A supercontinent! The idea that the continents were all connected into one supercontinent.
100
What is a plate boundary?
The place where two tectonics plate meet.
100
Why does oceanic crust go under continental crust when they converge?
Oceanic crust is more dense than continental.
200
What layer of the earth is the Core?
Inside!
200
What is Continental Drift Theory?
The idea that the Continents are constantly moving.
200
Describe a Convergent boundary.
Two plates collide, or come together.
200
What causes a mid ocean ridge?
Divergent boundary of oceanic/oceanic. AKA sea-floor spreading.
300
What layer of Earth is the Mantle?
Middle (between the crust and the core).
300
What is Sea-Floor Spreading?
a geologic process that occurs when tectonic plates move apart, creating new ocean floor.
300
Describe a divergent boundary.
Two plates divide, or move apart.
300
What causes a trench?
When an oceanic plate converges and sinks below other crust
400
What are the three compositional layers of the Earth?
Crust, Mantle, Core
400
What theory do we use today to explain how the continents move; combines the ideas of Wegener and Hess
Plate Tectonics Theory
400
Describe a transform boundary.
Two plates slide past one another.
400
At what boundary does sea-floor spreading occur?
Diverging plate boundaries
500
What are the two mechanical layers of the earth?
Lithosphere and asthenosphere
500
What scientist came up with the Continental Drift Theory?
Alfred Wegner
500
What happens to crust at a convergent boundary?
Crust is destroyed
500
What boundary creates a rift valley?
The divergence of two continental crusts.
600
Describe the lithosphere.
Sits on top of the asthenosphere. It is rigid, brittle and solid.
600
What scientist came up with the idea of sea-floor spreading?
Harry Hess
600
What happens to crust at divergent boundary?
Crust is created
600
When two Oceanic plates converge, which plate will subduct?
The older one
700
Describe the Asthenosphere.
Under the lithosphere. It is plastic-like and flows. This is where convection currents happen.
700
Compare oceanic and continental crust.
Oceanic crust is younger and more dense.
Continental crust is older and less dense.
700
What happens to crust at a transform boundary?
Crust is neither created nor destroyed.
700
What forms folded mountains?
The convergence of continental/continental crust