People in New Jersey who were shaken up by a sonic boom on Thursday afternoon can rest easy. The cause wasn’t an earthquake, seismic blast, or artillery, the boom was caused by a stealth fighter jet in a test flight nearby.
Rumbling reports started at about 1:30 p.m. Spooked people took to social media to report tremors, which were felt every few minutes for about an hour, NJ.com reported. People in four New Jersey counties, as well as in Long Island and as far away as Connecticut, experienced the tremors.
According to The Associated Press, residents said buildings also rattled a bit, they heard loud booms and felt the ground shake beneath their feet. Of course, with these reports came speculation and many insisted the shaking was caused by an earthquake or a seismic blast.
— USGS (@USGS) January 28, 2016
A U.S. Geological Survey physicist counted nine booms over about 90 minutes that were recorded in southern New Jersey and along the eastern seaboard to New York, according to ABC News. Almost immediately, the agency refuted claims that an earthquake had struck New Jersey. The military piped in and said “not I” as well, and other theories were quickly tossed out, leaving a mystery behind.
By the afternoon, the U.S. Navy changed its tune and admitted that their flight tests caused the sonic boom heard ’round the east coast. Turns out, these tests were conducted during the exact same time period the tremors and shakes rattled the area around 1:30 and 2:30 p.m.
Spokesman Connie Hempel said that such supersonic flights are done almost every day in the same area they were conducted Thursday, but normally, people don’t feel a thing.
“Aircraft from the Naval Air Station execute supersonic flights almost daily, and most of these sonic booms are never felt on land. However, under certain atmospheric conditions there is an increased potential to hear the sound.”
The jet that caused the boom was flying off the eastern shore in a “cleared military flight area,” which runs parallel to the Delmarva Peninsula occupied by Delaware, Maryland, and Virginia.
The test was being conducted by the stealth fighter jet F-35C. The Navy specified that the jet was from the Naval Air Station at Patuxent River, Maryland and performed the supersonic flight at the same time the boom was felt across Jersey.
Did you feel that? Earthquake-like tremors felt in N.J., N.Y. blamed on 'sonic boom' via mashable https://t.co/EXtgbOFiuF
— Andrea Toribio (@dea_tabs) January 28, 2016
This is what caused your house to rumble-Pentagon says it was testing the new F-35C fighter News 12 Long Island pic.twitter.com/0h8e14qOcn
— Drew Scott (@DrewScott12) January 28, 2016
The Navy’s leading testing squadron said the test was routine and admitted in its statement that the F-35C “may have resulted in sonic booms.” In all its testing and training, the military takes precautions to make sure civilians are not affected.
“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. Other military aircraft also frequently use the ranges for testing and training.”
The F-35C is the Navy’s first stealth carrier and reaches speeds up to 1,227 mph.
What exactly is a sonic boom? It can be explained by comparing it to the wake left behind by a speeding boat. When a boat cuts through the water, it creates waves both ahead of and behind its path, which the boat will travel through. But, when the craft outstrips them, another wake is created that is more like a single wave — it’s made out of all the smaller ones that would’ve been created ahead of the boat, but didn’t because it went too fast.
The same description applies to planes flying through the air, only they produce sound waves. If a plane is traveling slow enough — like the boat — sound waves are created ahead of it. If it flies faster than the speed of sound, it creates a sonic boom, which is the wake of the sound waves.
According to USGS, the boom travels through the air with the plane and therefore hits the ground at different spots and different times as it travels, which explains why Thursday’s tremors were felt not just in New Jersey, but across the eastern seaboard.
[Photo By Chris Parypa Photography / Shutterstock]