The Restless Earth: Tectonic Plates Flashcards
The EARTH’S surface is separated into what?
Tectonic plates.
What is at the CENTRE of the Earth?
Core.
What is the CORE made up of?
Solid iron.
Nickel.
What is AROUND the core?
The mantle.
What is the mantle made up of?
Semi-molten rock.
How does the mantle MOVE?
Very slowly.
What is the outer layer of the Earth called?
The crust
The crust is very…
Thin.
20km wide.
What is the crust divided into to?
Lots of slabs called tectonic plates.
Where do the TECTONIC PLATES float?
On top of the mantle.
What two types of crust are the PLATES made up of?
Continental.
Oceanic.
Continental crust is…
Thicker.
Less dense.
Oceanic crust is…
Thinner.
More dense.
Why are the plates MOVING?
Rock in the mantle underneath them is moving.
What are the places called where PLATES meet?
Boundaries.
Plate margins.
What are the 3 types of PLATE BOUNDARIES?
Destructive plate boundary.
Conservative plate boundary.
Constructive plate boundary.
What happens to the plates at a destructive plate boundary?
Two plates are moving towards each other.
Continental plates meet.
Smash together.
No crust is destroyed.
Give an example of a DESTRUCTIVE plate margin?
Along the east coast of Japan.
What is a destructive plate boundary?
Oceanic plate meets a continental plate.
Denser oceanic plate is forced down into the mantle and destroyed.
What can a destructive plate boundary create?
Volcanoes.
Ocean trenches.
What is an OCEAN TRENCH?
Very deep section of the ocean floor where the oceanic plate goes down.
What happens to the PLATES at a constructive plate boundary?
Plates move away from each other.
Give an example of where two plates move away from each other
At the mid-Atlantic ridge.
What happens at a constructive plate boundary?
Magma rises from the mantle to fill the gap.
Cools creating new crust.
