An earthquake epicentre is the

An earthquake epicentre is defined as the point on the Earth's surface located directly above the focus or hypocentre [2]. While the focus (hypocentre) is the actual point within the crust where the rupture or movement along a fault zone originates and energy is released [c1][t1], the epicentre represents the surface projection of this event [t9]. It is typically the first point on the surface to experience seismic waves and often records the highest intensity of shaking [c1][c4]. Seismographs are instruments used to detect these waves but are not the epicentre itself [c1]. The epicentre is not merely an 'approximate centre' of a group of quakes, but a specific geometric point vertically above the initial rupture point [c2][t5]. Therefore, option 4 accurately describes the epicentre as the surface point directly above the fault rupture zone.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 14: Earthquakes > Focus and Epicentre > p. 177
2. [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 17: Contemporary Issues > Earthquakes > p. 8