LEOPOLD - It wasn't exactly The Big One, but a 3.6-magnitude earthquake early Tuesday morning was The Big Topic in parts of Bollinger and Stoddard counties.
Many residents said they were awakened by a loud, thunderous noise and rattling windows at 2:30 a.m. when the quake hit.
"It sounded like an explosion," said Paula Miles of Advance. "I didn't feel the shaking so much. I didn't know what it was."
"At first, you think of everything but an earthquake ... a sonic boom or thunder," she said, adding that she realized what was happening as the house shook for five or six seconds. "I had a hard time going back to sleep."
The epicenter was located two miles west of Leopold in Bollinger County, said Christine Smith, earthquake education specialist for the Center for Earthquake Studies at Southeast Missouri State University.
Depending on the subsurface composition at various locations, the highest intensity level may not be at the epicenter.
The intensity level measures the severity of an earthquake in terms of its effects on the earth's surface and on humans and their structures. The magnitude is defined as a measure of earthquake size calculated from ground motion recorded on seismographs.
Evaluations of the quake's intensity varied. Based on some reports of glass rattling in Puxico, the Center for Earthquake Research and Information in Memphis, Tenn., rated the quake's intensity level at four.
But Smith, after hearing reports of pictures being knocked off the wall, said "you're getting to a level five." Level five quakes are when injuries can occur.
"The one thing I'm worried about is that people talk so much about big quakes," Smith said. "But the lower ones can do damage. Level five is where you start having the overturning of furniture like large bookcases."