Constructive plate boundary Flashcards
What happens at a constructive plate boundary ?
The plates are moving apart
Why do the plates move apart?
Due to convection currents in the mantle in the Earth.
What happens when the plates move apart very slowly?
Magma rises from the mantle.
The magma erupts to the surface of the Earth.
Also accompanied by Earthquakes.
What happens when the magma reaches the surface?
It cools and solidifies to form a new crust of igneous rock.
This process is repeated many times, over a long period of time.
The new rock builds up to form what?
A volcano.
Where to constructive plate boundaries tend to be found?
Under the sea.
Give an example of a constructive plate boundary?
Mid Atlantic Ridge.
What has happened at the Mid Atlantic Ridge?
Chains of under water volcanoes have formed along the plate boundary.
What could happen at the Mid Atlantic Ridge?
One of the volcanoes may become so large that it erupts out of the sea to form a volcanic island.
Give examples of a volcanic island?
Surtsey.
Westman islands near Iceland.
This type of movement happens where?
Under the sea.
As the plates move away from each other there is a gap left, what happens to this?
It is filled with magma rising up from the mantle below to form volcanoes.
FULLY.
Describe what happens at a destructive plate boundary.
The plates are moving apart creating a constructive plate boundary.
This happens under the sea.
When the plates pull away from each other cracks and fractures form between the plates where there’s no solid rock.
Magma then forces its way into the cracks and the surface to form volcanoes.
New land is formed as plates pull away.
Volcanic islands.
