Earthquakes are normally caused by underground rock breaking along a fault line. The seismic waves that cause the earth to shake are caused by this sudden release of energy. The plates or blocks of rock begin to move during and after the earthquake, and they continue to move until they become trapped again. As fluid near the center heats up, convection currents develop within the Earth's mantle. Particles pass more quickly as the core heats the bottom layer of mantle material, lowering its density and allowing it to rise. The convection current is started by the growing material.
