The terms epicenter and focus are often used in the context of earthquakes, but they refer to two distinct points related to the event.
The focus, also known as the hypocenter, is the exact point within the Earth where an earthquake originates. This is the location where the rock begins to break, resulting in energy being released in the form of seismic waves. The focus is located deep underground, and its depth can vary significantly depending on the nature of the earthquake.
On the other hand, the epicenter is the point on the Earth’s surface that is directly above the focus. It is often the location that people refer to when they talk about where an earthquake occurred, as it is the closest point to the source of the seismic waves that reaches the surface. The epicenter can be found using triangulation from seismic data collected at various locations.
In summary, the focus is the underground point where the earthquake starts, while the epicenter is the surface point that lies directly above the focus. Understanding this difference helps in accurately describing the location and the potential impact of an earthquake.