It is thick (10-70km thick), buoyant (less dense than oceanic type) and mostly old
What is continental crust
100
Heat expands the magma, making it less dense and allowing it to rise. Once the magma moves away from the heat source it starts to cool and becomes more dense and moves back down to the heat.
What is a convection current
100
boundaries where two lithospheric plates slide past each other with no crust being created or destroyed
What is a transform plate boundary
100
Geological features formed when magma rises to the surface of the Earth and escapes through an opening in the crust.
What is a volcano
200
Pangaea
What is the name of the supercontinent suggested by Wegener?
200
12 major ones of these which move in different directions
What are tectonic plates
200
Long, narrow columns of hot material that flow upward from deep in the mantle
What is a mantle plume
200
Boundaries where two lithospheric plates are moving away from each other
What is a divergent plate boundary
200
Seismic activity that occurs due to a release in pressure and movement in the lithosphere. Mainly due to the interaction between lithospheric plates and faults in the crust.
What is an earthquake
300
Africa and South America fit together like puzzle pieces
What did Wegener notice about the continents?
300
The viscous layer of the Earth under the crust. Comprised of two parts: an upper part which is less fluid and a lower part which is heated by the core, resulting in convection currents.
What is the mantle
300
A well-known chain of islands created by a hotspot in the the middle of the Pacific Ocean.
What is the Hawaiian island chain?
300
Boundaries where two lithospheric plates are moving towards each other resulting in collision zones and/or subduction zones
What is a convergent plate boundary
300
This scale allows us to grade the intensity of earthquakes
What is the Richter Scale
400
Glacier scratches and scrapes, coal in the arctic, identical fossils in South America and Africa
What is the evidence that Wegener found to support his theory?
400
Used to map the depth of parts of the Atlantic Ocean
What is echo-sounding
400
Hot magma plumes from the mantle melt their way through the crust and lava bursts out of the surface of the crust forming volcanoes
What is a hotspot
400
formed where oceanic crust meets continental crust causing the less dense continental crust to override the denser ocean crust, forcing it downwards underneath the plate and into the mantle
What is a subduction zone
400
Volcanoes and earthquakes are very common in this area as they are characteristic of plate boundaries and the force and energy created when they collide.
What is the Pacific Ring of Fire
500
The continents were once connected and drifted apart over time
What is the theory of Continental Drift?
500
This ocean will shrink over time due to coverging plate boundaries and oceanic crust subducting.
What is the Pacific Ocean
500
Older rocks are found on Kauai, and newer ones are found on the Big Island of Hawaii, showing that over time connection to the magma plume was lost.
What is some evidence to support the theory of plate tectonics.
500
When these two plates collide, neither is subducted, becuase the rocks are relatively light and resist being forced down.
What is continental-continental crust convergence
500
Forms when plates move apart (divergent plate boundary) allowing magma to rise to the surface and form undersea mountains