The series of mystery booms that began being widely reported in 2017 has continued unabated into 2019. The phenomenon, if anything, appears to be becoming more frequent, although it is unclear if this represents an increase in the phenomenon itself, or merely in its reporting.

2019 has so far seen a small series of mysterious booms that echoed across northern Utah on January 5th, and a mystery boom on January 22nd in Kentucky’s Jackson County was followed the next evening by a second boom in Little Rock, Arkansas.

Since then, a slew of new reports have come from local news outlets around the country.

On January 31st, residents of Bradley, Polk, and McMinn counties in Tennessee reported hearing and feeling a large boom at around 11:30 a.m. Local authorities were at a loss after being able to rule out an explosion at a nearby chemical factory, but local meteorologist Paul Barys explained away the phenomenon as a 'frost quake.'

That same day, CBS17 ran a story about a series of mystery booms heard in Wake County, North Carolina. Residents there have reported a series of explosive booms heard late at night and in the early morning. Some speculate that a North Carolina Department of Transportation (NCDOT) project or explosive hunting targets could be to blame, but the NCDOT said the project doesn't involve any blasting, and investigators with the Wake County Sheriff's Office have been unable to pinpoint a cause for the booms.

More mystery booms were then heard up the east coast on February 2nd in the Rhode Island cities of Cranston and Johnston. Residents awoke to the loud noise shaking their houses at around 5:40 a.m. Although some residents blamed the sound on a nearby power plant, both the Johnston and Cranston Police Departments have yet to determine the explosive boom's cause.

Philadelphia, Pennsylvania saw a string of mystery booms on January 28th and February 4th; the booms reportedly occurred at around 2 a.m. and 11 p.m., respectively. The booms were loud enough to rattle houses and wake up local residents. The U.S. Geological Survey confirmed there was no seismic activity in the area, and local fire and police departments denied any knowledge of the booms; although the National Weather Service said that ‘frost quakes’ could have been to blame.

Then, in Brooklyn, New York on February 4th, another boom was heard at around 11:30 p.m. Residents speculated at the time that the boom could have been caused by a building collapse, car accident, or manhole explosion, but no explosion-related injures were reported in the area, and Con Edison and the NYPD both confirmed they had no knowledge of any explosions—or anything else—that could have caused the mystery boom.

Reports of strange, ‘cannon-like’ sounds beginning in early February were reported over the course of several days in Louisiana. Residents of Harahan, River Ridge, Wagaman, and Lakeview have all reported the mystery booms. Locals describe the noise as sounding similar to everything from thunder to fireworks to gunshots. Surveillance footage taken in Lakeview on February 4th shows a flash of light prior to one of the booms. Local power companies deny any involvement in the phenomenon, and local authorities are once again also at a loss to explain it.

Across the country in southern Arizona the latest in a series of mystery booms around Tucson reportedly occurred on February 5th at approximately 8:39 a.m. The phenomenon, also recently reported in the area on January 31st, caused homes to shake and windows to rattle. Seismological causes, blasting from mining operations, and sonic booms from jets stationed at local military bases were all ruled out. The mystery booms so far remain unexplained.

Finally, in Madison, Wisconsin loud booms heard by residents overnight on February 7th were explained as likely ‘frost quakes.’

“It was just like a loud bang. It sounded like it was in the house,” said the Singular Fortean Society’s lead designer and photographer Emily Wayland. “The noise startled the dog enough that he started to bark.”

A 'frost quake' is a natural phenomenon caused by extremely cold temperatures that cause a sudden deep freeze. Water in the ground expands quickly as it becomes ice, and this expansion causes soil and rock to crack, which produces tremors and booms.

Prior to the booms, southern Wisconsin did experience a significant drop in temperature overnight following a stretch of relatively warm, wet weather.

Reports of mysterious booms—sometimes accompanied by flashes of light and/or minor tremors—have been on the rise worldwide since 2017, continuing throughout 2018 and into this year. The booms have been reported across the United States in Alabama, Arizona, Arkansas, California, North and South Carolina, Colorado, Georgia, Idaho, Illinois, Indiana, Kentucky, Michigan, New Jersey, New York, Pennsylvania, Tennessee, Texas, Utah, and Washington; as well as in the countries of Russia, Denmark, England, and Australia.

Meteors and other natural events—such as frost quakes—remain popular explanations for the booms, and bolide meteors were blamed for mystery booms in California, Michigan, and Washington in 2018. However, no blanket explanation covers every occurrence of a mystery boom and many cases go unexplained entirely.

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