A series of no less than nine sonic booms rocked New Jersey on Thursday afternoon. Initially thought to be earthquake tremors, the US Navy reported that the booms may have been caused by flight testing.
At about 1:24 yesterday afternoon, people along the East Coast reported feeling tremors over the course of ninety minutes. Officials now know the shaking may have been caused by fighter jets.
People from as far away as Connecticut called local law enforcement agencies to report the booms, which many thought to be earthquake tremors.
Many individuals also used social media, such as Twitter, to report on the shaking they felt.
In some ways, sonic booms feel similar to earthquake tremors. Won-Young Kim, a scientist at Columbia University, explained to the Associated Press that people would likely have felt up to twenty minutes of shaking from each sonic boom. The fact that people on the ground cannot hear sonic booms heightens their resemblance to earthquake tremors.
The United States Geological Survey reported that their instruments had not registered an earthquake.
Instruments at the Lamont-Doherty Earth Observatory at Columbia University in New York City picked up vibrations from eight sonic booms yesterday afternoon. Scientists at the observatory confirmed the USGS report.
The sonic booms likely originated from two fighter jets, an F-35C and an F18, according to a spokeswoman for the Naval Air Station Patuxent River, who said that the U.S. Navy had been conducting flight testing off the coast.
A statement from the Navy said that flight testing like Thursday’s is an important part of aircraft safety.
"The test wing is critical to the safe test and evaluation of all types of Navy and Marine Corps aircraft in service and in development and is primarily based out of Naval Air Station Patuxent River, Md.," the Navy said.
Both the Navy and the Air Force use the area for testing.
Sonic booms occur when fighter jets travel faster than the speed of sound, about 768 miles per hour. When the sound waves hit the Earth, they can result in earthquake-like tremors, according to the USGS. The stealth fighter jets that caused Thursday’s sonic booms could have been traveling up to 1200 miles per hour.
This is not an uncommon occurrence. Just two days ago, in Charleston, S.C., local residents reported similar tremors. That shaking was likely caused by sonic booms from F-18 fighter jets on a training flight.
Concerned citizens reported the shaking to their local police departments by the hundreds, prompting local law enforcement agencies to request that citizens cease reporting the phenomenon.
According to a Navy spokeswoman, most sonic booms are never heard on land. Whether or not locals are able to hear sonic booms depends on atmospheric conditions.
There was no damage reported from Thursday’s booms.
This report contains material from Reuters.