© USGS
Thursday night's earthquake sent shock waves through most of Mahoning County.
The quake wasn't strong enough to create any damage, but it likely felt a lot stronger than a regular magnitude-2.5 rumble, said Michael Hansen, senior geologist at the Ohio Department of Natural Resources.
That's because rocks underneath the ground of river valley areas are mostly made up of unconsolidated sediments that amplify ground movement.
"That makes it feel higher intensity," Hansen said. That could explain the booming and crashing noises heard by some throughout the Valley. And although the initial magnitude registered a 2.5, Hansen said follow-up data could revise that number slightly higher.
"It may be 2.6 or a little bigger than 2.6, but not by much," he said.
Geologists have recorded earthquakes with epicenters in Mahoning County just six times - and all happened in the past 61/2 months.
All have occurred west of the Mahoning River, in close proximity to Salt Springs Road. The six earthquakes registered magnitudes ranging from 2.2 to 2.6. According to the Mercalli Intensity Scale, earthquakes between magnitudes 2.0 and 3.0 are felt by a few people, especially those on upper floors.
But why, after a lifetime with no earthquakes centered in Mahoning County, is the area averaging a quake per month?
Experts say there are a few reasons.