Prehistoric Earthquake Fault in Missouri That Isn’t New Madrid?

Since I was born and raised in Missouri and I am an earthquake nerd, I thought I knew everything there was to know about faults in Missouri. The only one in Missouri is New Madrid, right? Wrong.

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If you're fascinated by earthquakes and/or geology, you need to check out an interactive map shared by the USGS. The New Madrid Fault is the red area, but there's a yellow region just to the west of it.

That tiny area is known as the Western Lowlands liquefaction feature. The USGS says it is connected to "prehistoric earthquakes". Think Jurassic Park if it happened in Missouri and the dinosaurs were knocked down by quakes. More or less. Probably less.

Before I can actually say this is a recognized "earthquake fault", it appears there is a lot of uncertainty about the history of the Western Lowlands "liquefaction" feature. I find it curious that it has its own unique identity, but the evidence of violent shaking could just be a result of the historic quakes of the New Madrid Fault itself, right?

The USGS says "The causative fault or faults remain unidentified and uncharacterized." I think the layman's version of that is they're saying they have no idea.

For what it's worth, there's another tiny "fault" just north of New Madrid known as the "Thebes Gap area". It's just south of Cape Girardeau.

I definitely encourage you to check out the full USGS interactive map to find out where the shaky ground beneath us is.