Earth's Structure Flashcards
What are the layers of the Earth called in order from the outermost layer
Crust
mantle
outer core
inner core
What are the two types of crusts?
Oceanic crust
Continental crust
How do scientists know what the interior of the Earth is really like?
The differences in speed of seismic waves (P and S waves) generated by earthquakes can help to give us an idea of the Earths internal structure
Explain P waves
longitudinal waves, fast moving, can pass through solids
Explain S waves
transverse waves, slower moving, can only pass through solids
How do scientists know what the interior of the Earth is really like?
Chemical analyses of erupted lava and other volcanic products provide information about different compositions that exist in the mantle
Laboratory experiments determine the properties of rocks at the high pressures and temperatures of the earth’s centre
What are plate tectonics?
a theory that holds the crust is divided into 7 major and several minor tectonic plates that move
What was Pangea?
a theory that all the continents were once joined together into one large super-continent
What happens in a destructive plate margin?
when an oceanic and continental plate margin move towards each other.
The denser oceanic plate is forced under the less dense continental plate.
What does friction cause in the oceanic plate?
causes melting of the oceanic plate and may trigger earthquakes. Magma rises up through cracks and erupts the surface
What happens in a constructive plate margin?
When plates move apart
volcanoes are formed as magma wells up to fill the gap , and eventually a new crust is formed
What are collision margins?
they form when two continental plates collide
