Across the world, the sky is quaking with mysterious, explosive booms leaving residents rattled and baffling experts trying to determine their origins.
More than 64 different incidents involving loud, unexplained booms worldwide have been reported in 2017, according to a recent NY Post report.
The most recently reported skyquake in the U.S. occurred near Daytona Beach, Florida, on Dec. 3, prompting nearby residents to search for answers on social media.
Birmingham, Alabama, residents experienced a similar event last month, which local media dubbed the “Bama Boom.”
The “Bama Boom” occurred on Tuesday, Nov. 14, around 1:30 p.m. local time, according to Fox News.
National Weather Service officials in Birmingham tweeted shortly after the boom was reported, stating: “Loud boom heard: we do not see anything indicating large fire/smoke on radar or satellite; nothing on USGS indicating an earthquake.”
Some of the possible explanations for loud booms could be lightning from distant thunderstorms, large meteors entering the atmosphere, earthquakes, mining operations such as blasting and super-sonic aircraft.
“Shallow, brittle earthquakes and underground mine bumps can do this, causing both shaking from below and sound in the air,” AccuWeather Meteorologist Jim Andrews said. “Then there are both natural and man-made causes originating in the atmosphere.”
Supersonic aircraft would be a strong candidate as to the cause, Andrews said. Natural causes could be a meteor surviving entry into the atmosphere or particularly exceptional lightning, given that a thunderstorm is occurring.
A similar occurrence to the “Bama Boom” was reported in June earlier this year along the San Diego coastline, rattling doors and windows.
After initially denying any involvement, a Navy spokesman told the San Diego Union-Tribune that several jets went supersonic, causing the boom.
“Those two aircraft went supersonic about 35 miles from the coast,” Kakiel told the Union-Tribune. “Usually you don’t hear the side booms travel that far. It was kind of surprising to us.”
Since June, there have been several new reports of loud mystery booms in the San Diego area, most recently in early November, according to NBC San Diego.
The November news report suggested a meteorological phenomenon of clashing air masses might be another potential source of the strange rumblings.
“The event may have been caused by a meteorological phenomenon generated by the contrast of hot and cold air masses,” according to the report.
@NASA did u just do testing over Florida? Lots of booms over Volusia County. Scared the daylights out of us.
— Michele Kopf Vitale (@MicheleRVitale) December 1, 2017
In addition to different air masses colliding, Andrews said temperature and atmospheric stability can greatly impact sound as it travels, serving to both amplify the wave and allow it to travel over a longer distance.
He said atmospheric stability, temperature, air masses and topography can alter and affect how sound travels in any given area.
“You could have sounds that are being channeled away from their origin, increasing in loudness and changing in their patterns,” he said.
The origin of a sound might be relatively simple, but it produces a more mysterious rumbling as it moves farther away from the source.
The local Birmingham NWS office had no answer to what caused the “Bama Boom” but suggested it could have been caused by supersonic aviation or a meteorite surviving an atmospheric entry as the event occurred near the peak of the Leonid meteor shower.
NASA scientists had no answers as to the cause, adding that the Leonids are too small to make it through the atmosphere to cause the boom reported, according to Al.com.
Days later, another strange boom with mysterious origins was reported in the Denver, Colorado, area, according to a local CBS station.
A follow-up report from the same Colorado news station stated an over-pressurized storage tank erupted at a nearby oil and gas facility around the time of the reports. That was offered as the most likely cause, according to the report.
However, not all origins of the reported sounds have been so easily uncovered. Andrews stressed there are likely many causes both natural and man-made that can be attributed to these types of events around the world.
“With that said, the universe almost surely has many secrets yet to be unlocked,” Andrews said.