“A lot of people felt it just sitting in their chairs,” said Pam Tucker, the director of Columbia County Emergency Management Agency.
Reports of shaking windows, blinds, pictures, desks and other unsecured items came in after the earthquake, Tucker said. No damage was reported in the Augusta area, she said.
The Augusta-Richmond County Municipal Building on Greene Street was one shaken building, she said. Taller buildings typically feel tremors more, Tucker said.
Other reports came from the Columbia County Board of Education administration building on Hereford Farm Road and the Bridgestone plant in Graniteville, she said.
Christian Poppeliers, an associate professor of physics at Augusta State University who has researched seismology, said his class felt tremors and noticed a wall hanging move in their third-floor classroom.
“Everyone in class looked up at the same time. There’s no mistaking there was an earthquake,” he said.
The tremors felt in Augusta were from the energy waves traveling outward in all directions from the earthquake’s center, he said, like the waves formed in a pond after throwing in a pebble.
“It’s definitely big enough to feel,” Poppeliers said.
Shallow earthquakes like Tuesday’s, less than 10 miles below the Earth’s surface, are generally felt more, but the Augusta area would have felt the Tuesday’s quake even if it were a normal 15 to 20 miles deep, Poppeliers said.
Reports quickly spread across Facebook and Twitter on Tuesday afternoon from people in the area feeling the earthquake.
The vibration did not trigger seismic alarms at Thurmond Dam, said U.S. Army Corps of Engineers spokesman Billy Birdwell.
As a precaution, however, visual inspections were conducted at all three Savannah River dams – Thurmond, Russell and Hartwell – and the diversion dikes near Clemson University.
“They found no visible signs of impacts at any of the dams,” Birdwell said, adding that normal operations continued without interruption.
Earthquakes occur periodically in the Augusta-Columbia County area, which lies along the Fall Line, where the Coastal Plains and Piedmont regions meet.
For decades, scientists have monitored the region around the corps of engineers’ earth-and-concrete Thurmond Dam for seismic activity, which has included dozens of small quakes.
According to the National Earthquake Information Center in Golden, Colo., Thurmond Lake is one of the major earthquake centers in Georgia and South Carolina, where pressure changes caused by water in huge reservoirs can activate seismic activity.
The corps routinely reinspects the dam after even very minor quakes and maintains seismic detectors throughout the dam.
Seismic activity is frequently studied in the lake area, where the Eastern Piedmont Fault System runs from the Alabama-Georgia line through South Carolina, bisecting the 70,000-acre reservoir.
The largest recent quake in the lake area occurred Aug. 2, 1974, and registered 4.2. Three other quakes were recorded in nearby Edgefield County, S.C., in 1996, measuring 2.5, 2.3 and 2.2.
Experts say Augusta is unlikely to experience a serious quake. The only major recorded quake in the Southeast occurred in 1886 in Charleston, S.C., claiming 110 lives.