Question

which of these lies on the Earth's surface-seismic focus or epicenter

Answer 1

Seismic Focus refers to the point where the earthquake starts and the point where the quake motion is highest. It is the point where the frequency of waves is toughest and the exact place where the tectonic plates hit themselves.

Epicentre is the centre of the starting waves, which also is a resulting cause for shockwaves originating after the quake.

Answer 2

The Epicenter is found on the earth’s surface directly perpendicular to the focus.

Focus is a point within the earth's surface from where the seismic waves originate.

Focus helps to locate the location. Focus is the point of inception of an earthquake. The Epicenter stays above the focus on the earth’s surface.

Once the energy waves are released, seismic waves travel to all directions away from the focus thus causing an earthquake.