By MINDY KEPFIELD

Staff writer

Yvonne Adams Powell thought someone had backed into her garage Saturday night when she heard the loud “boom” outside her home near the football field.

She looked up and saw a ceiling fan sway and wondered if this was ab earthquake.

“Most likely!” said Mike Carroll who heard and felt the blast from his house on the north side of Marion County Lake.

The sharp explosion reminded him of a familiar long-ago sound, he said.

“Like when they used to blast in the quarry near Florence,” he said. “We could feel those in town.”

The mild earthquake, which measured 2.4 on the Richter scale and was centered about 3 miles below the surface, was the second quake to jostle the area in a week. A smaller one, only 2 on the Richter scale happened Nov. 16.

“It’s in the annoying level, not a damaging level,” said Rick Miller, senior scientist with the Kansas Geological Survey.

The quakes are in the same location over recent years, an area known as the Nemaha uplift which skirts along the eastern part of the county.

Scientists have been keeping an eye on the area, he said.

Smaller, shallower earthquakes like Saturday’s can produce a thunder-like noise which happens when the ground shakes at a certain frequency, he said.

“Our ear can hear pretty low frequency earthquakes,” he said. “We have a high enough range to hear them with our ear.”

Dogs have better hearing than humans and can hear temblors deep beneath the surface, giving some truth to the folk wisdom that dogs hear a quake before it hits.

“They do appear to hear, in advance, what we cannot hear,” he said.

There has been talk in recent years that some quakes in south central Kansas have been partly due to the larger volume of wastewater injected into the ground.

“Scientists have seen a clear uptick in earthquakes with the increase in fluid,” he said, adding that Marion’s quakes probably were not linked to brine disposal.

The temblors also are nothing that would put scientists on alert, he said.

The county could feel “a couple more pops” that measure 2.5 and 2.6 on the Richter scale in the upcoming months — none of them damaging.

“But we always could be surprised by Mother Nature,” he said. “That is the hardest thing to predict, but there is not a monster looming in the background.”