The epicenter (from the Greek ἐπί epí “on, over” and κέντρον kentron “center”) refers to the point on the earth's surface in relation to an earthquake that is perpendicular to the focus of the earthquake, the hypocenter .
When determining the location (localization) by seismological institutes, earthquake sources are simply assumed as point sources. In reality, however, these are fracture surfaces that have different dimensions depending on the strength of the earthquake. Earthquakes with small magnitudes have fracture surfaces with lengths of a few meters to a few hundred meters, while the fracture surfaces of very strong catastrophic events can extend over several hundred kilometers.
As a rule, the damage effect of an earthquake is most pronounced at the epicenter, as it depends primarily on the distance from the focus of the earthquake. However, the focus mechanism and the geological composition of the affected region also have an influence . Sedimentary basins , for example, can cause resonance effects, which can lead to significantly stronger amplitudes of the soil movement on the surface. The greatest intensities and thus the most severe damage therefore do not necessarily occur exactly at the location of the epicenter.
Outside of seismology, the term is also used for a place with particularly high activity or as a synonym for center . This use is controversial.
- Peter M. Shearer: Introduction to Seismology . 2nd Edition. Cambridge University Press, New York 2009, ISBN 978-0-521-88210-1 ( limited preview in Google Book Search).
- Definition from the Austrian Society for Earthquake Engineering and Structural Dynamics
- Edward A. Keller, Nicholas Pinter: Active Tectonics: Earthquake, Uplift, and Landscape . 2nd Edition. Prentice Hall, Upper Sadle River, New Jersey 2002, ISBN 978-0-13-088230-1 .