Earthquake rattles southwest Illinois, serves as reminder to be prepared, official says

Todd Eschman
·4 min read

The U.S. Geological Survey confirmed what Washington County residents thought they felt Sunday night – an earthquake.

A 3.1-magnitude quake shook parts of southern Illinois and the metro-east shortly after 10 p.m. Its epicenter was near Waltonville, or about 12 miles southwest of Mount Vernon.

No major damage or injuries have been reported, according to Matt Bierman, director of the Washington County Emergency Management Agency. But he said it served as a timely reminder that southern Illinois region sits atop the New Madrid Seismic zone, an active system that extends hundreds of miles across four states including parts of Arkansas, Illinois, Kentucky and Missouri.

“Instead of allowing this event to scare you, use this real world event to help you review and update your family emergency plan,” Bierman said in a statement. “This includes practicing earthquake drills, identifying safe locations within homes, and securing heavy furniture and other potentially hazardous items.

“We are grateful that no one was injured during this event.”

According to the Illinois Emergency Management Agency, the New Madrid Seismic Zone averages about 200 measurable “events” per year, most of which are not felt. Tremors between magnitude 2.5 and 3.0 occur annually with a 4.0 or greater about once every 18 months and 5.0 or above every 10 years.

The New Madrid Fault caused some of the largest earthquakes in U.S. history including 8.2- and 7.4- magnitude earthquakes on consecutive February days in 1811 and a series of quakes ranging from 7.0 to 8.6 in the winter of 1812.

“Accounts from the Feb 7th 1812 earthquake, claims that the Mississippi actually ran backwards for several hours,” Bierman wrote in a release. “The force of the land upheaval 15 miles south of New Madrid created Reelfoot Lake, drowned the inhabitants of a Native American village; turned the river against itself to flow backwards; devastated thousands of acres of virgin forest; and created two temporary waterfalls in the Mississippi.”

The earthquake was one of eight reported in the U.S. and Canada on Sunday. The biggest was a 4.6-magnitude in rural British Columbia.

The U.S. Geological Survey rates earthquakes on a scale relative to the amount of damage they can cause:

2.5 or less: Usually cannot be felt.

2.5-5.4: Often felt, but causes only minor damage. There are an estimated half-million worldwide each year.

5.5 to 6.0: There may be slight damage to buildings and other structures. They are more rare, though, with 350 or so annually.

6.1-6.9: The 100 that occur annually may cause significant damage in areas that are highly populated with a density of buildings.

7.0-7.9: This is a major earthquake with serious damage, injuries and deaths. The planet averages about 10 to 15 each year. The Loma Prieta Earthquake that caused $6 billion in damage in the San Francisco area in 1989 was at the lower end of this range.

8.0 or more: Can destroy whole communities at its epicenter. There are maybe 1 or 2 each year.

The U.S. Geological Survey reports there is about a 10% chance of a 7.5 to 8 magnitude earthquake in the next 50 years. For a New Madrid quake of a 6 magnitude, there is about a 30% chance in a 50-year window.

WHAT SHOULD I DO IF I FEEL SHAKING IN AN EARTHQUAKE?

Public safety experts urge you to follow this mantra: “Drop. Cover. Hold on.”

Here are some other tips from ShakeOut.org, which is sponsored in part by the Federal Emergency Management Agency, the U.S. Geological Survey and the National Science Foundation:

  • Drop to your hands and knees where you are and don’t run outside. This position protects you from being knocked down and reduces your chances of being hit by falling objects.

  • If you are in a wheelchair or walker, lock the device in place. Cover your head and neck with one arm and hand.

  • If a sturdy table or desk is nearby, crawl underneath for shelter.

  • If no shelter is nearby, crawl next to an interior wall. Stay on your knees; bend over to protect vital organs. Hold on to the table or desk until the shaking stops.

  • If you have shelter, hold on to it with one hand and be ready to move with your shelter if it shifts.

  • If you have no shelter, hold on to your head and neck with both arms and hands.