Question

The point on Earth’s surface directly above the focus is the _____.
A. pole
B. circum-centre
C. origin
D. epicenter

Answer 1

Hint: By focus, in the question we mean the point where the earthquake originates. We are asked to find the term that represents the point that is perpendicularly above the focus on the surface of the earth. You could recall what each given option represents and also their respective locations and hence find the answer.

Complete answer:
Hypocenter or the focus is the point where an earthquake or an underground explosion originates. Epicenter is the point that is directly above the focus on the surface of the earth.
During earthquakes, most of the time it is the epicenter that encounters greatest damage. The word epicenter was derived from the Latin word ‘epicentrum’ meaning situated on a center.
Hence, we find that the answer to the question is option D.

Additional information:
Focus of earthquakes is actually the point at which the fault slipping begins. The fault rupture is actually known to begin at the focus then expected to expand along the fault surface. The fault ruptures when the stress becomes insufficient to continue breaking the fault. The magnitude of an earthquake can be related to the total area of its fault rupture.

Note:
Now that we found out the answer as epicenter, let us discuss where other options are located. First one is the pole. The geographic pole is known to be either of the two points on earth where the axis of rotation of earth intersects its surface. In geometry, circum-center is the point where the perpendicular bisectors of the sides of a triangle intersect. If by origin we mean the origin of the earthquake, then, the origin of the earthquake actually takes place at the focus or the hypocenter.