What are the hypocentre and epicentre?

The hypocentre is the point of seismic focus in the ground (i.e. the point from which seismic waves originate) and is generally designated by its depth, longitude and latitude.

The epicentre is the vertical projection of a hypocentre onto the Earth’s surface (i.e. the point on the Earth’s surface directly above the hypocentre) and is generally designated by its longitude and latitude.