Sonic boom? Earthquake? Big bang theories abound
- Sonic boom? Earthquake? Big bang theories abound
BY TERRY JOYCE
Of The Post and Courier Staff The earthquake experts say it wasn't a shaker, and military authorities say they didn't have the kind of planes in the air that can make a sonic boom.
But whatever it was, the noise that rattled Lowcountry communities about 1:30 p.m. Friday commanded a lot of attention.
"There was this extremely loud, percussive noise," said Reynolds Pommering of Mount Pleasant. "My sister (on James Island) said she heard it, too, and that's eight miles across as the crow flies. I first thought somebody had run into the building."
Local police said they didn't know what the noise was, but they received a lot of calls.
"We've had no reports of any fires or explosions," said Charles Francis, a spokesman for the Charleston Police Department. "But we've gotten calls from Daniel Island, Wadmalaw and James Island."
In like fashion, earthquake experts at Charleston Southern University and the University of South Carolina ruled out any temblors in the area.
"We have nothing on our seismographs," said Abhijit Tantopadhyay with the S.C. Seismic Network at USC.
Marlene Roberts with the Earthquake Education Center at CSU offered a similar remark.
"I checked the charts and we had no earthquake on it," Roberts said. "We assume it must be a sonic boom."
The Air Force, the S.C. Air National Guard and the Marines all have planes stationed in South Carolina that can break the sound barrier. But all three military bases insisted they had nothing in the air that could have created a sonic boom.
"We get a lot of noise complaints," said Capt. Don Caetano, a spokesman for the Marine Corps Air Station at Beaufort. "But that's because people don't like F/A-18s flying low over their houses."
Three of the nine fighter squadrons assigned to Beaufort were busy practicing the approaches they must use whenever they land on an aircraft carrier. All three will be deployed aboard the aircraft carrier Enterprise next month.
But those approaches are flown at low speeds, not the 700-mile-an-hour clips needed to generate a sonic boom. And they flew nowhere near Charleston.
Sonic booms can travel a long way, especially over water on a cloudy day, and the military often flies over water. But the list of suspects ran short after calls to Shaw Air Force Base and McEntire Air National Guard Station. Neither base had any of its supersonic F-16 fighters in the air.
The Navy gets a clean bill, too. Navy spokesman Pat Dooling in Jacksonville said there were no carriers operating off the South Carolina coast that could have launched boom-making planes. Also, the Navy no longer has any supersonic jets assigned in Jacksonville.
So what's left?One theory batted around was that it could be "Seneca Guns," a folk explanation used to describe unexplained booms often associated with the coast of North Carolina. Such booms have been experienced in North America since before the Age of Flight, some as early as the 18th century.
Richard Thacker, a senior forecaster for the National Weather Service in Charleston who has studied the phenomenon, said there are a number of theories about what causes Seneca Guns, from gases being released from the sea floor to a sudden rush of cold air that hits the Gulf Stream.
With phone calls pouring into the weather service Friday from Mount Pleasant to West Ashley, Thacker said his office wasn't sure what caused the boom.
"It could be anything from a sonic boom to a Seneca Gun," he said. "We may never find out what caused it today."
Terry Joyce covers the military. Contact him at tjoyce@... or 745-5857. James Scott of The Post and Courier also contributed to this story.