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. Cutaway view of the reverse fault. The earthquake starts at the focus, with slip continuing along the fault.

Detailed explanation-2: -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-3: -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-4: -When a rupture occurs along a fault, the strain energy stored on either side of the fault is released in the form of seismic waves and heat. These seismic waves propagate away from the ruptured fault zone and through the geologic layers of rock and soil.