Label the parts of an earthquake: Which term refers to the point on Earth's surface directly above the earthquake focus?

• A. Fault Trace
• B. Hypocenter
• C. Fault Plane
• D. Epicenter

Answer: (D)

When an earthquake happens, energy is released at a location inside the Earth called the focus or hypocenter. The point on the Earth's surface directly above that underground origin is the epicenter. This surface point is what we typically reference in reports and discussions because it marks the outward projection of where the earthquake originated. The other terms describe different parts of the fault system: the fault plane is the actual slipping surface within the crust, and the fault trace is where that fault would intersect the surface, forming a line on the ground.