Natural Hazards (Destructive Plate Margin (The plates move towards each…
Destructive Plate Margin
The plates move towards each other.
This usually involves an oceanic plate and a continental plate.
As the plates collide, the oceanic plate is forced beneath the continental plate. This is known as subduction. This happens because the oceanic plate is denser and heavier than the continental plate.
When the plate sinks into the mantle, it melts to form magma. The pressure of the magma builds up beneath the earth's surface. The magma escapes through weakness in the rock and rises up through a composite volcano. The volcanic eruptions are often violent, with lots of steam, gas and ash.
An example is the Nazca plate, which is forced under the South American Plate.
This movement causes earthquakes.
Constructive Plate Margin
The plates move apart from one another.
The magma from the mantle rises up to construct new land.
This is in the form of a shield volcano;
The movement of the plates over the mantle can cause earthquakes.
An example of this is the Mid Atlantic Ridge.
Conservative Plate Margin
The plates move past each other.
They are side by side and move at different speeds.
As the plates move, friction occurs and plates get stuck.
Pressure builds up because the plates are trying to move.
When the pressure is released, it sends out huge amounts of energy, which causes an earthquake.
The earthquakes at a conservative plate boundary can be very destructive because they occur so close to the earth's surface.
There are no volcanoes at a conservative plate margin.
An example of this is the San Andreas Fault.