The earthquake in Indiana is fairly significant, actually.
It is a quake of 'The North American Craton."
It is also considered by USGS to be a 'felt quake.'The craton of the North American plate IS the 'continent.' Without it the plate would be a random amount of terra firma and water. The craton is composed of very, very stable geological rock.
When an earthquake occurs on or better put, within the craton it is transmitted far distances and can do damage hundreds of milies away. See, where the equake is 'felt' is sometimes where the damage occurs RATHER THAN the epicenter which can be very deep. The 'felt' quake is more the worry when these episodes exist in the craton than where the epicenter is.
Earthquake Hits Central Indiana (click title to entry - thank you)
Last Updated: December 30, 2010 9:37:32 am(Lawrenceburg, Ind.) - A magnitude 4.2 earthquake hit about 15 miles south of Kokomo, Indiana Thursday morning.
The quake was about 50 miles north of Indianapolis.
The U.S. Geological Survey said the quake was three miles deep and hit at 7:55 a.m. Eastern time.
The USGS website has data showing the quake was felt in the western suburbs of Chicago, as far north as Kalamazoo and Ann Arbor, Michigan and also felt in central Ohio....
So, the future mayor of Chicago might want to check with emergency services and find out if he needs to visit any of the 'felt zone' for cracks, gas leaks, injuries at the hospital with people that have no clue what occurred to them, etc.
This might help from the USGS, then again, maybe not. The USGS works on 'their summary' from its beginning to the completed documented event with 'on the ground' and 'seismic' investigation. The 'study' of any quake isn't ignored after it is reported. That is true of hurricanes and volcanoes and other threats to human life. So, this is THE BEGINNING of the report on this quake, not the 'final' report. Knowledge also 'goes forward' as information presents itself. So the completion of this 'file' may receive information for decades or as technology changes, for centuries and beyond. It is important work that the USGS, NASA and NOAA do, beyond the 'simple reporting' (sorry if that sounds like a put down, it isn't, they consider the 'reporting' to have high priority) of an event and its initial economic impact.
EARTHQUAKES IN THE STABLE CONTINENTAL REGION
...However, (click here) 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....
One thing that the 'agencies' at any level have to remember is that the gas industry has been turned loose in the USA to disrupt very stable geological rock for the sake of petroleum industry profits. CEO's are scared to death of losing a 'cent' of income, you know?
It is why the Republicans always want to shut down the government rather than giving the American people knowledge of their lives and how to avoid living on a 'gas land mine.'