People looked to the ground, then the sky, where booms echoed as if the entire state was breaking.
“We heard something like a boom or like a swishing sound and then the whole house, the windows were shaking,” Angel Itri of Galloway told NBC10 Philadelphia.
As the booms sounded again and again, and the ground shook, residents took to social media to fearfully ask: What they heck is going on?
“I believe we just had 2 back to back minor earthquakes at the Jersey Shore in the past 30 minutes,” wrote William Felton of Palermo, N.J., on Facebook.
Some said they heard the sounds as far away as New York and Connecticut.
Soon, authorities also expressed their concern.
“Have you felt the tremors?” wrote New Jersey State Police on their Facebook page, beneath a photoshopped image of deep cracks opening in the earth. “We are hearing reports of tremors here in Jersey. For the record, we have not reported any seismic blasts anywhere in the State. If you’ve felt the tremors today, let us know in the comments where and when. We’re working to confirm.”
Theories abounded online. Some linked the phenomenon to earthquakes elsewhere in the country. Others insisted it was from offshore drilling. A handful used the tremors to make a joke at the governor’s expense.
Roughly half an hour after the shaking ended, there finally came an answer.
“We have confirmation of a sonic boom, not an earthquake, in S NJ today,” tweeted the National Weather Service in Mount Holly. Shortly afterwards, the U.S. Geological Survey confirmed that there had been nine sonic booms, not earthquakes.
But many locals were unconvinced. Some asked why there would be so many sonic booms in such a short span of time. Others said they didn’t hear any noise, but rather just felt shaking.
“Sonic booms don’t constantly cause interval ground shaking with no noise,” wrote Stacey Goller of Manahawkin on Facebook. “They have a noise like a firecracker but there was no noise and just shaking. So they better come up with something other than this sonic boom theory. Not buying it.”
The confusion deepened when a local military base said it was not to blame.
“We’ve also received reports of ground shaking here in South Jersey,” wrote officials from the McGuire Air Force Base near Toms River. “We do not have any aircraft capable of producing a sonic boom and our training ranges are currently clear of operations. We’re working with local and civilian authorities to determine the cause of the incident.”
The mystery was finally solved Thursday evening when the Navy admitted to accidentally terrifying the Garden State.
“Aircraft from Naval Test Wing Atlantic were conducting routine flight testing in the Atlantic Test Ranges this afternoon that included activities which may have resulted in sonic booms,” the Navy said in a statement. “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. Other military aircraft, including both Navy and Air Force, also frequently use the ranges for testing and training.”
A Navy spokesperson said that the planes tested on Thursday were the F-18 and the F-35C, the Navy’s version of the controversial Joint Strike Fighter.
At $400 billion, the Joint Strike Fighter is the most expensive weapons program in Pentagon history. Its pilot’s helmet alone costs more than $400,000. The F-35 is meant to be a versatile plane that in one iteration can take off vertically — making it ideal for airplane carriers — and support troops on the ground engaged in close combat, but also beat other planes in dog-fights, appear nearly invisible to radar and fly at close to Mach 2.
But the Joint Strike Fighter has drawn criticism. Some military experts say it has underperformed so far compared to the ten tried and tested airplanes it is supposed to replace.
Thursday’s sonic booms could well have been the result of a face-off between the F-35 and the older F-18 Hornet, a supersonic jet that the Navy has used since the mid 1980s.
The Joint Strike Fighter has been blamed for rattling New Jerseyans before, once in 2014 and once last year.