plate margins

Question 1

Destructive Plate Margin

Answer 1

Oceanic crust forced underneath Continental crust (convection currents).
Deep sea trench is formed.
Crust melts in the mantle, magma erupts back to the surface creating composite volcanos and violent earthquakes.
Nazca and South American plate.

Question 2

Constructive Plate margins

Answer 2

Convection currents pull Oceanic crust away from Oceanic crust. Magma rises to fill the gap.
Sea floor spreading.
Shield volcanos and earthquakes.
Mid-Atlantic ridge (between UK and America).

Question 3

Conservative Plate margin

Answer 3

Convection Currents make plates slide past each other.
Jagged edges, sometimes get stuck.
Pressure builds until sudden release ( plates jerk forwards).
Earthquakes,
San Adreas fault , Western coast of North America.