High Quality Content by WIKIPEDIA articles! The Flinn-Engdahl regions (or F-E regions) are a division of the Earth into seismic zones. In seismology, it is the standard of localizing earthquakes. The scheme was proposed in 1965 by Edward A. Flinn and E. R. Engdahl. The first official definition was published in 1974 and a revision in 1995. Borders of the F-E regions may differ from political boundaries. For instance, the F-E region 545 ("Northern Italy") also includes parts of France, Switzerland, Austria and Slovenia. After the 1995 revision there are 754 F-E regions, subsequently numbered from 1 to 757 with three gaps (172, 299 and 550) at dissolved regions. The regions are grouped into 50 larger seismic regions.