Mysterious Booms Return to Clintonville, Wisconsin?

Have we finally heard the mysterious booms in Clintonville, Wis.?

Townspeople say they are back, and an audio engineer may have given us our first listen.

It was a bit more than a week and a half ago that residents of the town of 4,500 people west of Green Bay, Wis., 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 on March 20.

It also recorded seismic activity the day before but could not pinpoint its location. The mystery brought reporters from across the country, including yours truly.

We met plenty of folks who whose slumber was shattered by the booms.

Brian Sullivan, an audio engineer, wanted to see if he could record one of the booms.

We watched him set up his recording gear. The first night, no luck. But, Sullivan said he captured a boom from this past Saturday. It was 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.