``We even heard it at our house,'' said Columbia County emergency management Director Pam Tucker, who lives in Evans, about 10 miles northwest of Augusta, where the quakes appeared to be centered. ``It sounded like thunder, but there wasn't a cloud in the sky.''
The first quake struck at 11:48 p.m. Monday, while the next two came at 4:52 a.m and 5:22 a.m. Tuesday, said John Bellini, a geophysicist for the U.S. Geological Survey's National Earthquake Information Center in Colorado.
The magnitudes were the minimum people can typically feel, said Donald Stevenson, a seismologist for the Westinghouse Savannah River Company, which monitors earthquake activity for the U.S. Department of Energy.
``You would just feel a bump in the night,'' he said. ``There's no damage that would be associated with something that small.''
Most callers to Columbia County 911 reported ``booms, vibrations and shaking windows.''
There hasn't been a significant earthquake (magnitude 4.0 or above) in the area since the 1970s, and Tuesday's temblors were no exception, Bellini said. Since 1974, there have been only 12 quakes within 40 miles of Evans, which is situated where the coastal plain meets the Piedmont region.
The only earthquake to register above a 4.0 struck Aug. 2, 1974, Bellini said. Generally, it takes an earthquake of at least 4.5 magnitude to cause any damage to buildings.
The U.S. Geological Survey states that Thurmond Lake, located between Georgia and South Carolina is a major earthquake center for the two states