A mysterious boom that shook portions of Appling late Monday was confirmed Tuesday as a minor earthquake, according to Columbia County authorities.
The event, which registered a 2.1 magnitude on the Richter scale, occurred at 9:26 p.m. and was located near Columbia and Appling-Harlem roads, said county Emergency and Operations Director Pam Tucker.
The temblor was not listed on national earthquake monitors, but was confirmed Tuesday by a seismologist at Savannah River Site, she said.
“This would explain the loud boom and shaking that many residents felt,” said Tucker.
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 U.S. Army 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 promote seismic movement.
The largest recent quake in the lake area occurred in Lincoln County on 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.