A 4.4-magnitude earthquake struck on Wednesday morning in rural East Tennessee, rattling homes as far away as Atlanta in the region’s most powerful jolt in more than 45 years.

The earth shook around 4:14 a.m. local time just outside Decatur, Tenn., a city of about 1,600 people near the Great Smoky Mountains, according to the United States Geological Survey. The earthquake was shallow, about five and a half miles below the surface, sending ripples throughout the area and into neighboring states.

It was the strongest earthquake in East Tennessee since a 4.7-magnitude earthquake struck near Maryville, Tenn., in 1973, the National Weather Service said.

A second earthquake in the same area on Wednesday, a 3.3-magnitude jolt, struck about 15 minutes after the first one, the U.S.G.S. said. The earthquakes were not on a known fault, the U.S.G.S. said, but they did occur in one of the most active earthquake zones in the Southeast. That area, known as the Eastern Tennessee Seismic Zone, extends to the northern parts of Alabama and Georgia.