And the reason behind this is that these major tectonic plates are made up of minor tectonic plates. And, at times, the collision between the major tectonic plates can be felt even in the middle of the plate. But depending on the way that these main tectonic plates collide with each other, various types of boundaries can be formed.
Such as the Convergent boundary, when one plate collides and slips under the other. Or Divergent boundary, where both plates move away from each other. Or Transform boundary, when both plates move parallel against each other. Among these, the most dangerous earthquakes occur when convergent or transform boundaries are formed. And the boundary of the Pacific plate is a convergent boundary. It has a specific sub-type known as the Subduction Zone.
In the Subduction Zone, causes the most powerful earthquakes because in this type of collision, when one plate collides with another, it goes right under the other submerging into the mantle. And when this happens, as you can see in the diagram, a deep cavity or hole is formed under the sea on the boundaries of the two plates, which is called a Trench.
