A diagram of an convergent (destructive) plate boundary.
What is the Plate Tectonic Theory?
The Plate Tectonic Theory is the theory that the earth's crust was divided into plates. These plates move around the mantle at different speeds and directions. Sometimes the plates collide into each other, causing a boundary. There are three types boundaries: Insurgent (constructive), convergent (destructive) and transform (conservative).
Insurgent Plate Boundary
![Picture](/uploads/6/0/5/3/60530909/2139333.png?250)
Insurgent boundaries are when two plates move away from each other, causing magma to rise through the crack and cool to form a new layer of crust.
Convergent Plate Boundary
![Picture](/uploads/6/0/5/3/60530909/8823984.png?189)
Convergent plate boundaries are when two plates push against each other and the oceanic plates is pushed under the continental crust. Volcanoes can occur as a result if the magma rises through any cracks. Mountains can also be produced if the continental plate is pushed upwards. Earthquakes can occur as a result.
Conservative Plate Boundary
![Picture](/uploads/6/0/5/3/60530909/807341.jpeg?200)
Conservative boundaries are when two plates move past each other horizontally without producing or damaging any of the earth's crust.
Where Was the Earthquake?
The earthquake occurred in the Japan Trench in a subduction zone off the coast of Japan. A subduction zone is where two plates meet and the oceanic plate is pushed down under the continental plate into the mantle. The friction causes the oceanic plate to melt and turn into magma that can then rise through gaps in the crust and form a volcano. Mountains can also be formed if the continental crust is pushed upwards. It can also produce earthquakes.
What Were the Causes of the Earthquake?
The earthquake was caused when the Pacific Plate (oceanic plate) suddenly moved under the North American Plate (continental plate). After the earthquake, scientists drilled down into the mantle and found a layer of clay lining the fault. They believe that the clay allowed the plates to slide as far as they did (around 50 meters) and causing the big earthquake and tsunami.