After the near record-setting Illinois earthquake today (it was M5.2, just a hair behind the Illinois record M5.3 quake in 1968), a reader suggested that I republish a piece I wrote three years ago about the New Madrid Fault, which straddles the area where Missouri, Illinois, Kentucky, Tennessee, and Arkansas meet.
Bearing in mind that the area that rocked today was the Wabash Valley seismic zone, north and east of the more active New Madrid seismic zone:
Keep an eye on this. The last time the New Madrid Fault really shook was back in 1895, and it destroyed the whole business district of Charleston, Missouri. The last time New Madrid really, really shook was December 1811 through February 1812, and it was big:
The quake was felt by nearly everyone inside the zone marked “V”–basically everyone east of the Mississippi outside of New York and the New England states.
Buildings inside the area marked “VII”–which includes Nashville, Louisville, and St. Louis–suffered some structural damage. Areas inside the VIII zone–Paducah, Cairo, Cape Girardeau–suffered considerable damage, even in well-built structures. The IX zone–Memphis–was heavily damaged, with many buildings thrown off their foundations.
The zone marked “X”–Jonesboro, Arkansas–was mostly destroyed. Brick buildings insde this zone would just shatter, since masonry, unlike wood, doesn’t flex.
The problem with the December 16, 1811 quake illustrated above was that two more of equal or greater strength followed within 60 days. Another quake of this size, given the greater population along the river now, would put the Great San Francisco Quake to shame.
The New Madrid Quake of 1812