Divergent plate boundaries Flashcards
What are divergent plate boundaries?
They’re when two plates are MOVING AWAY from each other.
What hazards occur at divergent plate boundaries?
Volcanic and earthquake hazards.
Why is there a ridge from the oceanic : oceanic plate boundary?
Lithosphere gets thinner, less pressure on mantle, mantle rises and spills out in submarine eruptions, creating a ridge.
Why are there earthquakes at divergent plate boundaries if the plates are moving away from one another?
Transform faults cause e-quakes as oceanic plate does not move as one plate but in smaller pieces, enabling friction.
Tend to be quite small earthquakes.
give a located example of an oceanic : oceanic divergent plate boundary:
The Mid-Atlantic Ridge :)
Why is the Atlantic ocean growing by a few cm a year?
Because new plate is being made at the mid-atlantic ridge. Ridges are created by dry lava, creating the mountains.
What happens at a continental : continental divergent plate boundary.
Hot spot or plume has caused the continental plate to upwarp.
Over time, crust move away from plume.
Crust moves away and sinks down, creating a RIFT VALLEY.
broken crust moves in opposite directions and lithosphere solidifies to create an oceanic crust. This then creates and Oceanic : oceanic and a MID-OCEAN ridge.
Where is an example of continental : continental plate?
East African Rift Valley.
What hazards can occur at continental : continental plate boundaries?
Volcanoes BUT the feature being created here is the crust subsiding (collapsing) from being stretched.
