GEOLOGY

Detailed explanation-1: -The spot underground where the rock first breaks is called the focus, or hypocenter of the earthquake. The place right above the focus (at the ground surface) is called the epicenter of the earthquake.

Detailed explanation-2: -The earthquakes originate in tectonic plate boundary. The focus is point inside the earth where the earthquake started, sometimes called the hypocenter, and the point on the surface of the earth directly above the focus is called the epicenter.

Detailed explanation-3: -The focus is the place inside Earth’s crust where an earthquake originates. The point on the Earth’s surface directly above the focus is the epicenter. When energy is released at the focus, seismic waves travel outward from that point in all directions.

Detailed explanation-4: -The point inside the Earth where an earthquake originates is known as the focus (or hypocenter) of the earthquake. The point directly above the focus at the surface of the earth is called the epicenter of the earthquake. At the epicenter, the most vigorous shaking is caused during an earthquake.

Detailed explanation-5: -P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.