Question

define focus and epicenter of an earthquake

Answer 1

Focus is the point where the edges of the plates give way resulting in sudden movement which causes earthquake.
Whereas epicentre is point just above the focus on the earth surface.
hope it will help you ......

Answer 2

Answer:

Focus of an earthquake is located deep under the ground. Focus is the point inside the crust where the pressure is released. The point on the earth’s surface above the focus is called the epicenter.

Explanation:

Epicenter is the place on Earth's surface directly above the focus, or hypocenter, where the earthquake happened. (Recorded during a 2007 teacher workshop on earthquakes and tectonics. Speaker is Dr. Robert Butler, University of Portland Oregon)

Keypoints:

Epicenter is the location on the surface of the Earth directly above where the earthquake starts. Focus (aka Hypocenter) is the location in the Earth where the earthquake starts.