BERGMAN, Ark. – The earthquakes this weekend didn’t cause any damage but they did spark plenty of discussion.
The Arkansas Geological Survey received more than 700 reports related to the 3.6-magniture earthquake that occurred around 7:40 Sunday morning — thousands of others took to social media.
The epicenter of the 3.6 and the subsequent 2.5 and 2.4 aftershocks were located near Bergman, Arkansas in Boone County.
“I didn’t know whether to grab my cell phone or the gun,” says Deborah Elsea, who lives near Lead Hill. “I was like, ‘is there a big piece of machinery coming towards the house?’”
Most residents in the Ozarks fell into one of two categories during the earthquake: either they thought a tank was rolling through their front yard or they missed the show altogether.
“I just completely slept through the entire thing,” says Jennifer Madrid. “It didn’t bother me at all. I knew I was a heavy sleeper.”
The Arkansas Geological Survey says the area near Bergman tends to stay dormant. While there are a few small shakes, most quakes don’t come close to the 3.6 mark.
However, Arkansas Geological Survey assistant director, Scott Ausbrooks, says over time, strain and stress can build up in what are normally quiet areas, resulting in a larger than normal “pop.”
“If you think about, right now our continent, our plate boundary — North American plate — is moving away from Europe and Africa. That’s why the Atlantic Ocean is getting wider. Well, that energy is transferred into these faults in the interior [of the country],” he says.
Ausbrooks says his organization will be working in the coming weeks to determine what fault the epicenter was located near.
He says the geological survey will also be exploring a known phenomenon called, “reservoir induced seismicity” or earthquakes caused by water. An example might be when a lake is filling up for the first time after a river has been dammed
Ausbrooks believes the increase in water level in Bull Shoals, as a result of recent flooding, could have caused a similar affect.
“The lake level has increased by 40 feet,” he says, “that’s a pretty significant increase over a short amount of time. So we’re going to take a closer look and see if there is some type of relationship there.”
Ausbrooks doesn’t believe a “big one” is on the horizon, but he says these smaller quakes should serve as a reminder to have a disaster plan in place just in case.
The Arkansas Geological Survey has seen similar size earthquakes in that part of northern Arkansas as early as 1925.
Ausbrooks says the last to approach the 3.6-magniture point was in Deer, Arkansas back in 2005.