As of October 2015, recent earthquakes occurred 11 miles southwest of Medford Oklahoma, about 19 miles southwest of Ovalle, Chile and 17 miles north of Sorong, Indonesia. Three significant earthquakes occurred in the vicinity of Illapel, Chile between Sept. 21 and 22, 2015.
The Illapel earthquakes took place near the boundary of the Nazca and South American plates. This is also true of the Ovalle quake, which took place in the same area. The Medford, Oklahoma quake was unusual in that it took place in a relatively stable area north of Oklahoma City and south of Wichita, Kansas. This was a magnitude 6.4 earthquake. The Sorong quake occurred around the boundary of the Australia-Pacific plate.