An earthquake hit northern Illinois just before 4 a.m. Wednesday, waking up residents throughout the region.
The 3.8 magnitude earthquake happened at 3:59:34 a.m., according to the U.S. Geological Survey, and was about 3.1 miles underground. The quake was felt as far away as Madison, Wis., which is 134 miles away, according to the USGS. There are also reports of the quake being felt in Michigan and Iowa.
The quake was centered about 1 mile south-southeast of Pingree Grove. The USGS initially had placed the epicenter 5 miles east of Sycamore and 4 miles west of Virgil.
The USGS originally said the quake was 4.3 in magnitude before downgrading it just before 8 a.m. Wednesday. Paul Stoddard, an associate professor in department of Geology and EnvironmentalGeosciences at Northern Illinois University, said the numbers are fluid during the first couple of hours after an earthquake.
John Bellini, a geophysicist with the National Earthquake Information Center, said the numbers are being revised as more data becomes available. The same is true as to the location of the epicenter, he said.
The quake woke Jesse and Camille Asanoski at their home in Rockford, they said. Jesse Asanoski initially thought it was a snowplow going by, but didn't see anything when he looked out the window.
"My pictures on the wall were all sideways and my cat was (scared,)" Camille Asanoski said. "We turned the TV on and saw it was a pretty good earthquake."
When the couple arrived at their restaurant, Tommy O's in Sycamore, Camille Asanoski noticed some of the knick-knacks on the walls had shifted.
"Who could have thought you would have an earthquake in Sycamore?" Jesse Asanoski said as he flipped a customer's omelet.
There is no known fault line in this area, Stoddard said, but there "is a fault there because there was an earthquake. Anywhere on the planet can see an earthquake. Some places get them a lot more frequently."
There have been a handful of earthquakes in northern Illinois during the last decade, he said, including one in 2008 that was south of DeKalb County and was registered at a 5.1 magnitude.
Earthquakes, generally speaking, are caused by a shifting of rocks, Stoddard said. In the Midwest, it's most likely due to what is calledglacial rebound.
"We used to have huge glaciers sitting over Great Lakes region and into Canada," he said. "When they melted, that releases a lot of weight from that part of the world. The surface of the Earth rebounds upward. Imagine taking a bowling bowl off a mattress, only with the earth it happens a lot more slowly. As the surface rises up, small adjustments in the rock happen occasionally. And we felt one this morning."
The Edwards family of Sycamore slept through the earthquake, except for 13-year-old Lilia.
"It seemed like it was just in my dream," she said. "It felt like the whole house shook."
It wasn't until the family overheard other people talking about the quake at Elleson's Bakery later in the morning that they learned it had even happened, Lilia's father, Jim Edwards, said.
There were no reports of damage called in to the police departments in DeKalb or Sycamore, nor to the dispatch centers for DeKalb or Kane counties, officials at those department said. Stoddard said a quake this small would result in little to no damage.
"I would say hundreds of calls came in (to the county dispatch center) shortly after 4 a.m," DeKalb County Sheriff Roger Scott said, most to report the shaking and of hearing a "boom" sound.
When the noise of the earthquake woke Jean Winter of Sycamore, she initially thought it was snow falling off the roof of her three-story townhouse.
"Then it just kept going and I thought, 'Nope, this is another earthquake,'" she said. "I lived in Chicago in the 1980s when we had one, and that one I blamed on the dogs shaking the bed."
Winter was relieved the quake didn't do any damage, she said.
"I had some things fall off the back of the toilet, but that was it," she said.
Larry Verhaeghe didn't feel anything shaking, but was suddenly awakened in his home in rural St. Charles by the quake, he said.
"I couldn't feel anything, but I woke up and knew something happened," he said. "I heard a lot of rattling, and thought for a minute the roof might have caved in."
Floyd Kocher of Sycamore was just getting out of bed when his house began to shake. It reminded him of a time he was outside and a jet broke the sound barrier overhead, he said.
"You could feel it the same way," he said. "I knew what it was. You figure it's an earthquake when the whole house shakes."
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