Ethel Woolsey, 85, was sitting in her South Salt Lake home Sunday night when she felt the floor move like waves under her feet.

Then her chair started to dance."It was such a funny feeling sitting there in the chair and having it rock in the wrong direction," Woolsey said.

Woolsey's chair was rocked by a 9:06 p.m. earthquake that registered 5.4 on the Richter scale and was centered 16 miles southeast of Salina, Sevier County, in the Fishlake National Forest. Sunday night's tremor lasted less than a minute but was strong enough to trip off an electric generator in Carbon County. It also jumbled a few smokestacks in Richfield and shook lights, floors and rocking chairs throughout the Salt Lake Valley.

A dozen small aftershocks late Sunday and early Monday followed the earthquake, which was felt in eastern Utah, southwestern Wyoming, western Colorado and northern Arizona, said Sue Nava, senior staff seismologist with the University of Utah Seismograph Stations. Waverly Person, head of the U.S. Geological Survey's National Earthquake Information Service in Golden, Colo., said small aftershocks may continue for two to three days.

According to Bill Alder, meteorologist in charge at the Salt Lake office of the National Weather Service, tremors reached as far north as Sunset in Davis County and Rock Springs, Wyo., and as far south as Kanab and Grand Junction, Colo.

The quake was strong enough to cause damage, but because of the remote location of the epicenter, no major damage reports are expected. None of the aftershocks have registered above magnitude 3 on the earthquake measuring scale.

In the Salt Lake Valley and Utah County, police agencies were flooded with calls reporting the quake. No reports of damage or injuries were received, however. Callers to the Deseret News reported feeling their homes shake and seeing light fixtures swaying for several seconds. Nancy Van Valkenburg, a reporter working in the Deseret News' downtown Provo office, said the quake shook her chair from side to side and the force knocked her to the floor.

Alder said some damage reports were received in the Richfield, Loa and Hanksville areas, where some reports of foundation cracks and falling stovepipes were noted.> Utah Power & Light Co. spokesman David Mead said the earthquake's vibrations tripped off a generator for about two hours at the Huntington Power Plant in Emery County, but no customers were without power. "The power deficit, if you will, was made up from other sources," Mead said. Among the power sources was UP&L's new merger partner, Pacific Power Corp.

Last Aug. 14 a quake measuring 5.3 on the Richter scale struck about 48 miles east of Salina. No damage was reported from that quake.