Water and limestone are likely the cause of sleepless nights and anxiety in Hamblen and Jefferson counties, according to an expert on the earth’s physical structure.
Kim Dillon woke up to a boom between 12:30-1 a.m. Sunday. A sound she thought was an earthquake was followed by two, smaller booms.
“The first boom was so hard it literally felt like every door upstairs just slammed shut and just literally vibrated the entire house,” she said.
‘It was like a C-4 explosion’
Kim and her husband, Josh, debated on evacuating their home. Without knowing what was going on, their minds began fearing the worst, including exploding natural gas lines near their home.
“It was like a C-4 explosion going off,” Josh said.
Tuesday, the two were still perplexed, without any idea of what they heard fewer than 48 hours ago.
Booms tracked since 2015 in Hamblen
Hamblen County Emergency Management Agency Director, Chris Bell, says their office has been tracking the events since 2015. He believes recent events are similar to a few from 2015.
That year, Bell says he connected with state and federal agencies to work to find a cause. He says the Center for Earthquake Research and Information at the University of Memphis set up nodes throughout the county, for a brief period of time, to study the events and were unable to find any activity.
While he was never given conclusive data, he says people within geological services told him both high water levels and cold temperatures can cause separations with underground limestone structures.
He learned when water freezes, it expands and could be the source of the booms and shaking felt in his county. The theory is also supported by the fact, he says, most reports are in early mornings or late evenings.
30 new reports of booms
While he believes this theory is the most likely because “it makes the most sense,” he would welcome an in-depth study from an outside agency.
Bell’s office submitted a new spreadsheet of more than 30 reports of booms to the state Tuesday morning.
While that number may seem low for an entire county, the reports are for individual areas. In many of them, there were multiple neighbors echoing the same experience. Those reports range from Saturday through Monday night.
‘Series of collapsing caves’
Dr. Katherine Stone, Assistant Geology Professor at Walters State Community College, concurs with those geology experts’ findings from four years ago.
“…we have a series of collapsing caves and of course the large booming noises,” Stone said.
Stone says while there are large mines in places like Jefferson County, she doesn’t believe they’re active enough to cause the recent commotion.
She’s convinced it’s caused by natural limestone caverns collapsing underground.
Basically, with so much rain in the region, she says it washed out the limestone.
Expect to hear more booms
Stone even demonstrated with a small rock and small solution of an acidic solution how quickly rock can dissolve. She cites many examples we see every day of limestone erosion, including natural caves throughout East Tennessee and sinkholes.
Ultimately, she says you don’t need to be worried.
With colder temperatures on the way, and frozen water expands underground, she believes you should expect more of these events in the region.
“It’s nothing we need to be overly concerned about, it’s just something we need to be aware of.”