Utah's earth rumbled again early Thursday morning when San Rafael Swell area experienced an aftershock to Sunday's earthquake.

The aftershock, which registered 4.6 on the Richter scale, was centered 30 miles south of Price, according to U.S. Geological Survey's National Earthquake Information Center in Golden, Colo. The aftershock was also registered by the University of Utah seismograph center.The shock awakened residents in the Price and Scofield area and was felt as far away as Grand Junction, but no injuries were reported.

A series of about a dozen temblors that shook rural Emery County this week should remind Utahns that "this is earthquake country," a University of Utah research seismologist said.

The strongest quake measured 5.4 on the Richter scale Sunday afternoon, said Jim Pechmann of the U. of U. seismograph center. It was preceded by two smaller quakes Sunday and followed by several aftershocks through Monday.

Pechmann said several more aftershocks could follow throughout the week.