On Friday, the USGS reported a 2.2 magnitude earthquake near Madison, Ohio. It happened just before noon at it’s epicenter.

This is the second earthquake near Madison, Ohio in the last week according to the U.S. Geological Survey.

How big was the earthquake?

A 2.2 magnitude earthquake is not that big when compared to other earthquakes. Magnitude is based on motion sensed by a seismograph which detects earthquakes.

The largest earthquake ever recorded in Ohio was a 5.4 magnitude earthquake in western Ohio in 1937. According to the USGS, it caused considerable damage in Anna, Ohio and other western Ohio communities felt its shaking.

Another indicator of earthquake size is intensity. This is measured with the Mercalli intensity scale ranging from 1 to 10. Friday’s earthquake is classified as a 2 on the Mercalli scale. This means no damage was found, but weak shaking could be felt.

Courtesy of U.S. Geological Survey

Where was it felt?

According to the USGS, earthquakes with a magnitude between 2.0 and 6.5 are felt anywhere between 0 and around 370 miles away when using the Richter scale.

Today, the Richter scale is not widely used except for local earthquakes like this one. According to the USGS, there were only two responses on where the earthquake was felt. Both were within 4.5 miles of the earthquake’s epicenter near Madison, Ohio.

Courtesy of U.S. Geological Survey

Not the first earthquake near Madison, OH

Friday’s earthquake was not the only earthquake near Madison, Ohio.

On August 28, a 3.6 magnitude earthquake was registered just before 11 o’clock that night. According to the USGS, it was classified as a 5 on the Mercalli intensity scale with moderate shaking. It could be felt for just over 340 miles from the epicenter near Madison, Ohio along the coast of Lake Erie.

Courtesy of U.S. Geological Survey
Courtesy of U.S. Geological Survey

Several earthquakes have happened here. That’s because Madison, Ohio sits near a fault line.

A fault line is where a fault cuts the earth’s surface according to the USGS. This is where a fracture exists between two blocks of rock.

Activity at the fault line near Madison, Ohio has been active for years. Several earthquakes are recorded from this fault line; however, they are typically not very strong. Some only register magnitudes under a 2.0.