Destructive plate boundaries Flashcards
What happens at a destructive plate boundary?
The plates are moving towards each other.
What plates does are at destructive plate boundaries?
Continental and ocean plates.
What happens to the Oceanic plate?
It is denser than the continental plate so as they move together the oceanic plate is forced underneath the continental plate.
Where does the oceanic plate go when its forced underneath the continental plate?
The subduction zone.
What happens when the oceanic plate enters the subduction zone?
It melts to form magma and the earthquakes are triggered.
When the oceanic plate melts to form magma in the subduction zone what happens?
The magma collects to form a magma chamber.
This magma then rises up through cracks in the continental plate crust.
As pressure builds up, a volcanic eruption may occur.
As the plates push together what plates is squashed?
Continental crust.
What happens when the continental crust is squashed?
Its forced upwards.
The squashing and forcing upwards of the continental plate is called what?
Folding.
What does the process of folding create?
Fold mountains.
How can fold mountains also be formed?
When 2 continental plates push towards each other.
Give examples of mountains which were formed by folding?
Himalayas and Alps.
Define convection current.
A movement within the Earth’s mantle caused by heat of the core.
Define magma.
Mixture of molten or semi-molten rock.
found beneath the surface of the Earth.
Define magma chamber.
A region under the surface of the Earth where hot molten magma collects.
Define plate boundary.
The regions where 2 or more tectonic plates meet.
It is the zone of intense seismic activity.
Define plates.
Large areas of the Earth’s crust that move slowly on the upper part in the mantle.
Often colliding and moving away from each other.
FULLY.
Describe what happens at a destructive plate boundary?
Convection currents in the mantle cause plates to move towards each other.
The oceanic and continental plates are involved.
The oceanic plate moves towards the continental plate and because its denser its forced underneath the lighter continental plate.
This process is called subduction.
Oceanic crust is destroyed and melts to form magma.
