Sullivan Earthquake Reassessed

Tuesday's earthquake originating near Sullivan, MO, at 3:10 a.m. rattled homes in our region and Illinois, but now has been deemed a magnitude of 3.9 rather than original reports of a 4.2 by U.S. Geological Survey Earthquake Hazards Program teams.

Additionally, the city closest to its epicenter was pinpointed as Richwoods, approximately 6 miles northeast of the quake's center.

Some local residents reported that they slept through the tremor, while others on early Tuesday morning indicated it definitely was .

Eureka resident Pam Schmitt Eder posted that when the earthquake woke her up, she thought someone had run into their house with a car.

A second Eureka resident Ann Martel posted she thought the quake was a train coming at first, and then realized that they never shake the ground that much.

A third reader indicated they thought the dog was shaking their bed, but looked and saw that their dog was asleep.

Another Eureka-Wildwood Patch reader, Joan G., who stated she lives outside of Macomb, IL, indicated she felt her recliner shaking while sitting in it. "At first I thought maybe my dog was shaking the chair, but I realized he wasn't by the chair," she posted on the site. "I sat very still and it was still shaking. It only lasted about 20 seconds or so. The chains from my ceiling fan were swinging also, which confirmed I wasn't imagining the shaking I felt. After sitting there for awhile questioning myself, I noted the time was 3:20 a.m."

This quake happened in what geologists call the Ozark dome region, which is outside of the New Madrid zone.

Another minor earthquake, measuring 2.6 magnitude, occurred near Sullivan on March 7, 2009, according to USGS data.

Missouri's worst recorded earthquake, which occurred on Feb. 7, 1812, in New Madrid, struck at nearly the same time as Tuesday's temblor. That earthquake happened at 3:45 a.m., with a 7.7 magnitude.

The one on Feb. 7 was the third and principal earthquake in a series that happened during 1811-1812. The town of New Madrid was destroyed. Many St. Louis houses were damaged severely. The meizoseismal area was reported to have ground warping, ejections, fissuring, severe landslides, and caving of stream banks.