The theory of plate tectonics states that the Earth’s lithosphere (top layer of the Earth’s crust) is split up into rigid sections called plates that are moving relative to one another as they move on top of the underlying semi-molten mantle. These plates are either continental, The North American Plate, or oceanic, The Nazca Plate.
Tectonic plates are powered by convection currents, which is the circular movement of magma within the mantle. These currents are powered by the core, which heats the magma, causing it to rise, cool and fall back down. This circular motion causes the plates, which float on the mantle, to move. The individual plates are separated by fault lines which extend from the surface all the way to the asthenosphere, at which point the fault disappears due to the plasticity of the rock that exists there. The earth’s plates are moved by convection currents in the mantle caused by localised concentrations of radiation and heat from the earth’s core. The plates are constantly in relative motion to each other, but this motion is extremely slow due to the incredible amount of mass being moved, friction, and the high viscosity of the asthenosphere. Where the different plates meet is called a plate boundary.
There are three types of plate boundaries and they are; Destructive margins, Constructive margins and Conservative margins. At a destructive margin the plates are moving towards each other. This usually involves a continental plate and an oceanic plate. The oceanic plate is denser than the continental plate so, as they move together, the oceanic plate is forced underneath the continental plate. The point at which this happens is called the subduction zone. As the oceanic plate is forced below the continental plate it melts to form magma and earthquakes are triggered. The magma collects to form a magma chamber. This magma then