Here’s a map of the New Madrid Seismic Zone for you. I heard a newscaster say today that the earthquake was due to movement along the New Madrid Fault. The earthquake, which struck 50 miles southwest of St. Louis, was felt early this morning in the St. Louis, Missouri, and southern Illinois area.
If you’ll take a look at the map, however, it appears that the earthquake was pretty far away from what is usually considered the New Madrid Seismic Zone. Map is courtesy of Geology.com.
After examining the data from the St. Louis quake, scientists noticed that there were no aftershocks at all, which is somewhat odd. The quake was only three miles deep and probably occurred along a previously unknown fault. Even the known faults in this area are not very well mapped. (I’m searching for a fault map of Missouri, and I’ll update this if I can find one.)
I’m wondering if this single, anomalous event, could somehow be related to the recent flooding along the Mississippi River. Could the extra volume of water from the flood have caused stress along a fault line? Or could the water have eroded some previous deposition and caused a shift in an adjacent formation? I haven’t read any hypothesis along these lines, but it does make me wonder if there is any connection between these two events. Sheer speculation on my part.
Here’s a video for you. Since the earthquake happened around three in the morning, there weren’t many people up and about; though the shaking apparently was enough to wake up some people. At any rate, I’ve posted videos from this source before because they’re short and to-the-point. I’m not sure if I understand the intro he’s got going here, but I like the graphics.