(CLINTONVILLE, Wis.) — Have the mysterious booms in Clintonville, Wis., finally been caught on tape?
Townspeople say they are back, and an audio engineer may have given ABC News its first listen.
It was a little over a week and a half ago that residents of the town of Green Bay, Wis., with a population of 4,500, said they were awakened from their sleep by loud booms that shook their houses. Night after night, there were more booms and more shaking.
The United States Geological Survey finally said it recorded a 1.5-magnitude earthquake on the morning of March 20. It also recorded seismic activity the day before but could not pinpoint its location.
Brian Sullivan, an audio engineer, wanted to see if he could record one of the booms.
ABC News watched him set up his recording gear. The first night, no luck. But, Sullivan said he captured a boom from this past Saturday, one minute before 4 a.m. It’s short, but it sounds like a boom.
This week, residents have been complaining about the booms returning to their small town. USGS said it has not been able to record any new activity and added that it has been windy in the area, which can create ground vibrations making small quakes difficult to record. There is discussion, but no decision, on placing a seismograph in Clintonville.
So is the mystery still solved?
Yes, says Paul Earle of the USGS. All these booms and shuttering are “consistent with small quakes” that are right under some of the houses in Clintonville.
Copyright 2012 ABC News Radio
Susan Scutti, CNN
Betsy Klein, CNN
Dylan Byers, CNN
Christopher Dawson, CNN