Columbia County Emergency and Operations Director Pam Tucker said several residents of the Old Louisville Road area near Harlem-Grovetown Road reported the noise about 8 p.m. Tuesday.
“I had more reports this morning,” she said in an email. “It was described as sounding like a ‘mortar round’ and ‘explosion’ with a short vibration.”
Rock quarries in the area said they had not been blasting, Tucker said, so she checked with a seismologist Wednesday morning to see if there had been an earthquake detected.
“The seismologist just notified me that after checking his equipment (that) there was no seismic activity in our area last evening,” Tucker said. “That leaves the conclusion that it was most likely a sonic boom.”
Similar reports in February, during morning hours, turned out to be blasting from Martin-Marietta’s Dogwood quarry on Columbia Road.