Earthquake (from Latin “terrae motus,” earth movement) is the ground shaking we feel when there is a sudden and rapid sliding of the surfaces of a fracture in the earth’s crust, which we call fault. For most cases we just know the epicenter and magnitude, without delving into how big the fault is, how much it has moved and in what direction. This is information that is not readily available, nor easy to find, but critical to understanding an event and the seismic risk of an area, especially in the case of strong earthquakes.

While a magnitude 3 earthquake is generated on a fault of a few hundred meters that dislocated a few centimeters, a magnitude 6 earthquake occurs on a 10-kilometer fault, with slip that can exceed one meter in some places. Then there are extreme events, such as the earthquakes in Turkey and Syria in February 2023 (magnitude 7.8 and 8.0), or Myanmar in March 2025 (magnitude 7.7), in which faults of hundreds of kilometers were activated with slip even exceeding 10 meters!

These events help redefine our idea of an earthquake; no longer a point, described by epicenter and magnitude, but a Finite Source.

The Finite Source portal makes available fault rupture distributions for significant seismic events. In this portal you can interactively access a major catalog of seismic events, for each of which you can view the fault in 3D, have a description of it, and download all the data for scientific analysis.