what is epicenter

The epicenter is the point on the Earth's surface that is directly above the focus or hypocenter of an earthquake. The focus is the actual location beneath the Earth's surface where the earthquake begins, and the epicenter is the map location on the surface directly above it. Although the earthquake originates underground at the focus, the epicenter is the surface location often used to describe the earthquake’s position. Locating the epicenter involves measuring the arrival times of seismic waves at multiple seismograph stations. By calculating the distance from various stations and using the intersection of these distances, scientists can determine the precise epicenter location. It is important to note that the area of greatest damage is not always at the epicenter, as fault ruptures can extend over a broad area, sometimes causing more severe effects farther away from the epicenter. In summary, the epicenter serves as the surface reference point for where an earthquake originates underground.