Expert: Loud Maryville 'booms' still a mystery

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MARYVILLE, Tenn. (WVLT) -- Several people have reported over the last few days hearing loud booms and feeling the ground shake. The United States Geological Survey said a series of earthquakes near Maryville are to blame, but an expert now has said there's no way the noise could come from a quake.

The Maryville Police Department said they felt it at police headquarters too, "The whole building shook."

Curtis Cardin said his house shook top to bottom when the first of what the USGS said were six earthquakes on Friday into Saturday.

"It was like a sonic boom and it shook the whole house," said Cardin. "It was major, I mean it scared you. It wasn't like a normal explosion or shock wave, this was powerful."

Tuckaleechee Caverns has a seismograph, and manager Ben Vananda said the boom registered a a shallow earthquake — two or less — near the Blount County Justice Center and Blount County Hospital area.

"The reason that they heard it was the seismograph waves were so shallow," said Vananda.

Early Friday, the United States Geological Survey earthquake map confirmed a 2.1 earthquake just off Union Grove Road near Union Grove middle and elementary schools at 12:57 p.m. in Friendsville.

Then, late Friday evening, the USGS released an update, saying the University of Memphis determined that a quarry blast caused the magnitude 1.9 earthquake.

On Saturday morning, USGS again updated its site, claiming that the earthquake on Friday was a 2.4 and was not due to a quarry blast. It also reported that another earthquake was felt on Saturday in the same area, at about 8:57 a.m. It was recorded as a 2.1.

Several people reported feeling the shake and hearing a series of loud booms in the area. Initially it was reported as quarry blasts but Vulcan Materials Company has claimed it wasn't them. University of Tennessee distinguished professor of geology Dr. Robert Hatcher said he doesn't think it from the quakes either.

"Usually a rumble, people who have been in earthquakes describe the noise as a train that comes in," he explained. "It's a rumble that comes in, that's the earthquakes way of coming through the earth. And so you hear a rumble, there's not a boom or something like that."

Dr. Hatcher said East Tennessee is no stranger to small earthquakes like the ones this weekend because it sits along what's called the East Tennessee Seismic Zone, and because of that the region could be due for a much larger quake.

"Because of the number of earthquakes we have we feel that there is a potential for large earthquakes here. We don't know what the recurrence interval is, it could be next year, it could be 1,000 years from now."

Carl VanHoozier, Community Relations Manager at Vulcan Materials Company, a quarry in Blount County, called WVLT News Friday night. On Friday night, he said, "The USGS is absolutely incorrect. There was no quarry blast today, or anytime this week. A 2.1 earthquake is pretty extreme. Our blasts are controlled and small. It's an earthquake, it's not a quarry blast."

However, early Saturday morning, VanHoozier contacted WVLT to report that there had been a blast during the week, but it was on Tuesday, not on Friday. He said Vulcan strives to be a good community neighbor.

The City of Maryville said several calls were received after the initial boom around 1 p.m. The city is calling it an "earthquake-like event."

"We have not found any visible evidence of a surface blast and we can confirm it was not a result of a quarry blast. Local seismographs indicate a possible earthquake. However, we do not know for sure the cause of the event. Officials from the US Geological Survey will need to make that determination," The city said in a statement earlier on Friday before the USGS earthquake was confirmed. "We expect to receive communication from the Emergency Management staff when the cause of the event is determined."

At about 2 p.m., the booming occurred again near Maryville City High School. A school representative said that it was felt by students and staff alike near the high school and Sam Houston School.

The representative said all the students are safe and the area has been checked.