An earthquake has rattled a swath of the Great Plains, from Kansas to Texas. The U.S. Geological Survey says the 5.6 magnitude earthquake struck about 7:02 this morning (SAT) about nine miles northwest of Pawnee, Oklahoma. No major damage was immediately reported. Staffers at the Wolf Creek nuclear power plant in southeast Kansas found no damage to the plant after the earthquake. The earthquake ties a 2011 temblor for the strongest in Oklahoma history. The U.S. Geological Survey has reported numerous aftershocks since this morning.