Earthquakes and volcanoes occur along the edges of the tectonic plates. Scientists have developed a theory that explains how these giant plates move, thereby creating, destroying, and re-forming continents and oceans over long periods of time. This theory is called the theory of plate tectonics.
Explanation: plate tectonics move constantly movement in narrow zones along plate boundaries causes earthquakes and plate tectonics come together and create pressure upon the magma deposit underground forcing it up into a volcanic eruption