Why does large earthquakes occur near subduction zones??
Basically put, as the two plates collide – one is “subducted” (meaning forced under the other). When this happens the plates grind and push each other and sometimes get stuck in their position. However, the force of the plates movement (illustrated by the plate tectonic theory) continues to act of the subduction zone until whatever made the plates stick in their position is forcibly moved out of the way – leading to a mass movement of the ground. Kinda like forcing one finger tip on your right hand against the other on your left until it slips and your hands move. *EDIT* I just realised you said “BIG” earthquakes.
