A minor but noisy earthquake rattled portions of Lincoln, McCormick and Columbia counties early Friday.
According to the U.S. Geologic Survey’s National Earthquake Information Center, the magnitude-2.8 quake occurred at 1:13 a.m.
Its epicenter was six miles southeast of Lincolnton and 21 miles northwest of Evans along Thurmond Lake’s Little River Arm, which straddles a prehistoric fracture known as the Modoc Fault.
Minor quakes have been recorded in the region, where pressure changes caused by water in reservoirs can promote seismic movement. Fractured bedrock beneath Thurmond Dam was stabilized with concrete when the structure was built in the early 1950s.
The largest recent quake in the lake area also occurred in Lincoln County, on Aug. 2, 1974, and registered 4.2.
Portions of the Augusta area, including most of Columbia County, lie atop the Eastern Piedmont Fault System, which runs from the Alabama-Georgia border all the way through South Carolina.