Mystery boom
© Fox24
Dozens of calls and social media posts are coming from people who say they felt an earthquake or a sonic boom in the Lowcountry sometime around 12:15 p.m. Monday.

Residents in Folly Beach, on James Island and in West Ashley all say they either heard or felt it.

"Shook the entire house," one Facebook user said.

"I'm on James Island and all of our houses shook," said another. "I was on the phone with a Folly Beach client and her place shook and now someone in West Ashley is saying the same."

The United States Geological Survey had no reports of an earthquake. The College of Charleston Geology Department didn't have anything on their seismometers about an earthquake either.

"Typically when we have the boom and the shaking, it's usually a sonic boom," CofC Department of Geology, Associate Professor Dr. Erin Beutel said. " I can't guarantee that, but given the lack of evidence for an earthquake, I'd say that's what it was."

Live 5 Chief Meteorologist Bill Walsh posted a radar image that appeared to show chaff off the coast near Folly Beach. Chaff is a form of countermeasure used by military jets to jam enemy radar. The release of chaff would not produce a sonic boom, he said, but its appearance on radar would at least corroborate reports of jets in the area at the time.

Associate professor of Geology at the College of Charleston Dr. Steven Jaume confirmed Walsh's report with that of a private meteorologist telling him that there appeared to be chaff on the radar at the same time as the apparent sonic boom.

"Base ops didn't have any reports of it so it wouldn't be our aircraft," Joint Base Charleston spokesman Marvin Krause said.

Officials with Air Station Beaufort said they did not have any aircraft at the time of the incident.

"Aircraft from Marine Corps Air Station Beaufort were not operating in the James Island/Folly Beach area July 23," Capt. Christopher Travis said."Any booms that were heard were not a result from our aircraft conducting flight operations in the area."