Mysterious boom in northern Indiana
© Stuart Meade
Some felt their houses shake, some heard windows rattle, and many others paused in alarm or curiosity after some kind of loud sonic incident or situation or ... something ... erupted apparently in an area east and south of the Goshen Municipal Airport Saturday afternoon.

Hard to say what was heard exactly - the most common description was a "boom" - and where the noise came from as the source remained a mystery into the evening hours. Speculation played out on Facebook with thoughts the "boom" resulted from aircraft, seismic activity, a weather phenomenon or Tannerite exploding during firearms target practice outdoors.

Who knows?

What seemed clear was a massive metallic-like explosion was heard and felt around 3:30 p.m. Saturday apparently somewhere in the area of Millersburg, Benton and New Paris - communities where this "boom" seemed to have the strongest effect, according to Facebook posts.

"Sounded like a garbage truck dropped a huge dumpster," Amber Oswald posted to The Goshen News.

"I am on U.S. 6 south of New Paris. Sounded like a grain wagon was dropped from 50'," Lance Miller also commented.

Several people said they heard a boom in Syracuse and Milford, while reports also came in from Ligonier, parts of Goshen, North Webster, Cromwell, Middlebury and Bristol, as well as in a couple of Michigan communities.

Adding to the mystery is questions of whether everyone heard one gigantically massively huge incident in a radius stretching from southern Michigan, over Elkhart County, western Noble County and into Kosciusko County, or whether multiple loud noises happened to occur at about the same time.

Elkhart County police received one call about the incident from around C.R. 127 near C.R. 46, and an officer was sent to respond, a police dispatcher said.

Sheriff Jeff Siegel was taking a walk with his wife east of Millersburg when the boom erupted during the sunny, unseasonably mild January day.

"We heard it loud and clear," Siegel said. "It literally sounded to me like a bomb going off."

The noise reverberated off industrial structures around them, so Siegel had a difficult time pinpointing where it came from, he said. He also had no idea what caused the sound.

On Facebook, Melody Ruse Ragdale, Kathy Hite Miller, and Erin Blosser each described the sound of two train cars colliding; Bryce Gast described a sonic boom, powerful enough to knock items off a window sill; Jillian Koeneman heard what sounded like cannon fire around C.R. 22; Mike Kissinger heard a low bass boom that shifted windows near the Tri-County Game Preserve in Syracuse; Brent Flaugh thought he heard a distant thunderclap; Andrew Raber heard what sounded like rattling metal after the boom; and Matthew King heard "nonstop" noises for the past week between New Paris and Foraker and assumed beaver dams were being eliminated.

Aaron Rink of Millersburg thought people might've heard a Tannerite explosion. The brand-name substance is commonly sold as an explosive chemical for target practice.

Rink, a farmer who owns Tycol Excavating, said some apparent Amish men were blowing up Tannerite targets for the past week near his business. He didn't hear Saturday's boom since he wasn't home at the time, but he said a large mixture of the substance would create a large blast.

"It would definitely be a very loud sound if you mixed up a gallon of it," Rink said.

A few pounds of Tannerite can explode like a firework, some YouTube videos show. Others show varying amounts of the substance of about 20, 25 pounds and more being used to destroy trees, vehicles, barns and silos.

Siegel admitted he doesn't know a ton about Tannerite, but even still, guessed an incredible amount would have to detonate for a blast in the Millersburg area to be heard as far south as Syracuse.

And how far could such a sound carry in the current weather?

Hard to say exactly, but meteorologist Cindi Clawson at WNDU-TV said Saturday's clear, mild conditions weren't ideal for carrying sound over long distances. Sound travels farther in colder, humid conditions.

Clawson also doubted frost quakes were the culprit.

The phenomenon is rare, occurring amid rapid, dramatic temperature shifts where water settles underground, freezes into ice in extremely cold temperatures and expands. The ground cracks, and loud booms resonate from the localized seismic situation.

The conditions since New Year's Day haven't been extreme enough to produce frost quakes, Clawson believes.

"We haven't been that cold. You've got to be well below freezing," Clawson explained, describing extremes as temperatures dropping quickly into single-digit to below-zero territory. "We just haven't seen a dramatic change in temperatures that much."

Temperatures rose from the upper 20s Saturday morning to about 50 degrees in the afternoon, and the temperatures kept roughly around that range since last Tuesday, National Weather Service information shows.

Linda Borntrager of Benton agreed what she heard didn't sound like a frost quake.

She remembered similar situations occurring last January, and what she heard Saturday was more like an explosion.

"Dad actually thought our house was exploding," Borntrager said, describing the incident as strong enough to shake their house along C.R. 31 down to the metal in their furnace.

She and her father speculated the sound originated southwest from them toward the New Paris Speedway along C.R. 29, she said.

Borntrager also thought the boom didn't resemble Tannerite explosions she's heard in the past, nor did it sound like aircraft noises she hears at the nearby Goshen airport.

But whatever occurred Saturday, she said she's heard similar-type sounds on-and-off for the past week.

Kosciusko County police took more than a dozen calls about booms around the county on Dec. 30 and New Year's Eve, the Times Union of Warsaw reported last Wednesday.

A Kosciusko County dispatcher said a few residents, including a couple around Milford, called police about hearing a boom Saturday. But they were scattered, not clustered in the same area, she said.

Messages were left with Goshen Airport and Grissom Air Reserve Base near Peru to check on whether the noise was related to aviation activity. Staff at the Battle Creek Air National Guard Base in Michigan said the facility wouldn't conduct military flights through the Goshen area.

The U.S. Geological Survey's website showed no earthquake activity in or around Indiana Saturday.

So, so far no definitive answers to what's drumming booms throughout the area, just lots and lots of guesses.