SOUTH CAROLINA (WCSC) - Reports of a loud noise and shaking houses like the ones that have poured in across the Lowcountry are indicative of a sonic boom generated by an aircraft, according to a release from the College of Charleston.
Dozens of calls and social media posts are coming from people who say they felt an earthquake or a sonic boom in the Lowcountry some time around 12:45 p.m. Tuesday.
"The ceiling fan swayed a little bit and the dogs came running out of the back bedroom, ears pinned back, really afraid," Mount Pleasant resident Robin Adams said. "The cat jumped off her tree, ran into the other room, so it was real significant, it was real significant."
Adams just moved to the area from San Francisco, and lived there during the huge earthquake of 1989. She said she thought it was happening again. She said nothing fell inside her apartment, but called it the biggest shudder she felt since the San Francisco quake.
In the release, from CofC Department of Geology, Associate Professor Dr. Erin Beutel said sonic booms are "pressure waves generated as the aircraft exceeds the speed of sound."
"They are perceived by the people on the ground differently under different atmospheric conditions," Beutel said in the release. "It can also take between 2-60 seconds after the plane passes through for the boom to be heard, and over the ocean, the pressure wave can travel further and be heard by more people than on land."
A spokesperson for Marine Corps Air Station Beaufort confirmed Tuesday afternoon planes were in the air at the time of the boom conducting exercises 15 to 20 nautical miles off the coast.
But it is not confirmed that those planes created a sonic boom reported across the area.
Live 5 Chief Meteorologist Bill Walsh posted a radar image that appeared to show chaff off the coast near McClellanville. 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.
Viewers in North Charleston, Summerville, Mount Pleasant, West Ashley, Moncks Corner, Goose Creek, Hanahan, Hollywood and St. Stephen are among those reporting windows rattling and entire houses shaking.
Comments on Facebook described what they felt. Some users who said they experienced earthquakes elsewhere described what was different about this event.
"I was in the earthquake near Richmond, VA about four years ago," Facebook user Cara Scarborough wrote. "I was sitting outside when this happened today on my front porch. The shaking was exactly the same but I don't remember a loud rumble like I heard today."
"Heard and felt it in Goose Creek around 1 p.m.," Facebook user Lisa Ashton Handwerk wrote. "I thought it was my washing machine shaking the house. Not quite like the earthquake we experienced a couple of years ago in Maryland. This was shorter in duration and louder with less shaking than the earthquake."
The US Geological Survey confirmed Tuesday afternoon no earthquake activity has been detected in the area.
Steve Jaume, an expert with the South Carolina Earthquake Preparedness Program, says it appears to be a sonic boom.
According to NASA, a sonic boom is the thunder-like noise a person on the ground hears when an aircraft or other type of aerospace vehicle flies faster than the speed of sound or supersonic.
A spokesperson with the FAA referred media inquiries to the military on the assumption that the vibration was a sonic boom, pointing out that civilian aircraft cannot fly fast enough to cause a sonic boom.
An official with Joint Base Charleston says he isn't aware of any exercises in the area that would create a sonic boom but is investigating.
Officials with Shaw Air Force Base have not yet responded to inquiries.