CLEVELAND — What caused the earthquake in Lake Erie Monday?
One scientist suggests heavy rain in Northeast Ohio could have triggered the quake, which measured 4.2 on the Richter scale.
“With all the rain we’ve been having lately, it’s just normal that the rain would have soaked down into the earth, along the fault zone and then just lubricated the fault enough to release some of the stress,” causing an earthquake, said David Saja, the mineralogy curator of Cleveland National History Museum, who has studied earthquakes and tectonic activity.
Cleveland is 3 inches above normal precipitation this year, according to the National Weather Service.
A seismologist at the Ohio Geological Survey doesn’t think that’s the case.
The epicenter of the earthquake was between 2 and 3 kilometers below the surface of the earth, well beneath aquifers and the zones of the earth that absorb rainwater.
He added that there’s plenty of recorded seismic activity in this part of the state, even in times of drought.
“There’s no real correlation that we’ve seen with rainfall and earthquakes,” Fox said.
Fox said the earthquake was caused by tectonic stress and strain.
With all the extra rain, Lake Erie’s water levels are at an all-time record high. The level is 30 inches above normal, meaning the lake has 43.4 trillion extra pounds of water. That extra pressure on the rocks beneath the lake could have played into the earthquake.
“There’s no way to knowing at this point,” Saja said.
Lake Erie in May was 6 inches higher than the record set in 1986.
One thing to note: the earthquake epicenter was 3 km below the earth surface. The lake is on average 60 feet deep.
In the context of the epicenter, the lake is “really just a little pond,” Saja said.
Fox said he would have to do more research to determine whether seismic activity and the lake water levels are related.
Another potential cause of the earthquake? Stress on cracks in the earth, built up over hundreds of miles away, over millions of years.
“It could come from anywhere,” he said.
We may never know what caused the quake. But by studying the stress fields, and various conditions, scientists can come closer to figuring it out.
U.S. Geological Survey scientists collect data from citizens who felt the quake — how they felt, what they did next — to help them understand it. Find the official form here.
Earthquakes are far more common in Northeast Ohio than you would expect, Saja said. ODNR reports that there have been at least 200 earthquakes with epicenters in Ohio since 1776. There have been at least six earthquakes this year in Ohio.
“If the average person feels it, they probably don’t even realize what it is and just go about their everyday lives,” Saja said.
If you were sitting in an chair on the lower floors of a building on a slab, you might have felt the earthquake on Monday. But if you were walking over to the copy machine, you probably didn’t feel anything.