What is the name for the source of an earthquake?

An earthquake happens when there is a sudden release of energy along deep fractures in the Earth's crust called "seismogenic faults". The source of the earthquake is called the focus or hypocentre and it can be located several kilometers deep below the surface of the Earth. The point located directly above the focus on the Earth's surface is called the epicentre, which is the area where the effects of the earthquake are the strongest. Generally, a shallower focus allows more energy to reach the surface, thus making the earthquake more damaging. In order to locate the epicentre and the depth of the focus, the arrival time of seismic waves at different detection stations can be used to calculate their positions through some trigonometric calculation.