|The Magnitude 3.8 earthquake in Illinois is not a "sign of 2012"|
|USGS Earthquake Map|
|Image courtesy of the United States Geological Survey, used under "Fair Use" provisions for educational purposes. Click for a full-sized image.|
On Wednesday, February 10, 2010 at 03:59:33 AM CST (Wednesday, February 10, 2010 at 09:59:33 UTC) a minor earthquake struck at 42.053°N, 88.412°W, about 2 km (1 mile) SSE (168°) from Pingree Grove, IL.
Almost immediately this earthquake became rolled into the 2012 mythology, and has been cited as an indicator that "2012 is real"1.
USGS: EARTHQUAKES IN THE STABLE CONTINENTAL REGION
At the bottom of the report page on the earthquake are were2 a couple of paragraphs that are worth reading. In particular:
…most of the enormous region from the Rockies to the Atlantic can go years without an earthquake large enough to be felt, and several U.S. states have never reported a damaging earthquake. The earthquakes that do occur strike anywhere at irregular intervals
The region is laced with known faults but numerous smaller or deeply buried faults remain undetected. Even most of the known faults are poorly located at earthquake depths.
Also see the USGS publication An Updated earthquake Catalog for Stable Continental Regions.
Historical earthquakes in Illinois
According to the USGS there have been several earthquakes in the region, dating back to 1795. In May 26, 1909, a quake struck at Aurora, about 21 miles South of the 2010 quake, that was large enough to knock over chimneys, and cause buildings to sway in Chicago. The 1968 quake (which was centered in the Southern part of the state) was large enough to be felt in 19 states, and as far away as Ontario and Boston.
What does it mean?
Basically, nothing. Earthquakes in this region are rare, but are not unprecedented. There is no reason to link this small earthquake with anything happening in 2012.
Earthquakes in this area are not unprecedented. Even 'stable' regions have earthquakes. There is no reason to link this earthquake to something happening in 2012.