sound-barrier-f-18.jpeg

In a file photo, a U.S. Navy F-18 flies close to breaking the sound barrier during a 2010 air show. Some have suggested the ground-shaking booms heard in Bordentown and Hamilton may have been sonic booms from jets. (MAZEN MAHDI | EPA)

(MAZEN MAHDI | EPA)

Jan. 28, 2016: Shaking in N.J. was likely a sonic boom, USGS says

Editor's Note: The story below is from April 1, 2015.

BORDENTOWN CITY — Mysterious, earth-shaking booms have been reported in recent weeks by dozens of Bordentown and Hamilton residents, and authorities are at a loss to explain them.

The most likely culprit, Joint Base McGuire-Dix-Lakehurst, says it wasn't them. While the military base routinely hosts artillery training on weekends and warns residents in advance, the mystery booms have come at odd hours and on weekdays when the range is inactive.

The latest boom jolted residents at 10 p.m. Monday. A closed Facebook group for Bordentown Township residents lit up with people asking each other, "Did anyone just feel that loud rumble?"

"Was in the garage and the garage doors both rattled hard and I could feel the rumble under my feet," was one of a dozen replies.

A similar online conversation unfolded on March 19 after the noise was heard around 9 p.m. Another series of reports occurred on March 17, a Tuesday. Some have reported hearing several booms in succession during the span of an hour.

Residents in adjacent Hamilton Township in Mercer County also reported hearing the noise.

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Bordentown City police they had heard about online chatter about the explosions, but no one there had fielded any calls about them. Bordentown Township police Capt. Norman Hand was unaware of the sounds Tuesday, and nobody in the police department was talking about it, he said.

As a lifelong resident of northern Burlington County, he is familiar with rumblings from the nearby base, he said.

The speculation has run rampant from earthquakes to environmental cleanup at an old steel mill site across the Delaware River to sonic booms from jets breaking the sound barrier.

The sounds are similar to those described in 2012 by residents in Manchester, Ocean County, where window-rattling booms plagued that area during the summer months and into the fall, according to news reports. Those explosions ceased soon after, without explanation.

Another possible source could be fighter jets from the Naval Air Station Patuxent River in Maryland, which run training exercises for F-35 and F-16 fighter jets in an off-shore area that spans Ocean City, Maryland, to Atlantic City.

But a spokeswoman for the air station said their fighters do not normally fly at night and the Bordentown area is outside of their normal range.

"It was nothing from Pax River,'' spokeswoman Connie Himple said. "That's pretty far out of our airspace.''

Hand, of the Bordentown Township police, offered this possible explanation: the thawing of the ground due to the intense cold weather this winter. He said a few weeks ago, his wife heard a loud bang in their home, and he heard the same sound while watching television at about 10 p.m.

"It sounded like a car hit the back of our house," Hand said. He checked the basement, and all his pipes were intact. He then learned from a television news program that the ground can make booming and loud cracking sounds when thawing from a prolonged cold period. "That's just my two cents," he said.

Keith Brown may be reached at kbrown@njtimes.com. Follow him on Twitter @KBrownTrenton. Find The Times of Trenton on Facebook.