New Madrid Seismic Zone Activity

[Thundersnow]

And now one in KY near Paducah...

https://fox17.com/news/local/24-earthquake-reported-in-kentucky

I’m having trouble finding this on recent activity outside of this article.

[Brandon]

Another this morning near Loretto Tn. 2.2

[cgauxknox]

1.6 under Tellico Lake followed by a 2.2 in Sweetwater,  both this morning.   https://www.wate.com/news/local-news/22-magnitude-earthquake-recorded-outside-sweetwater/2068950474

[Thundersnow]

There was also one in north Alabama.

Not sure if some of this is normal activity that we’re just noticing because we’re paying attention, but in addition to the uptick in frequency, it seems like we’re seeing tremors show up in places that don’t normally have them.

[bugalou]

Generated this this other day.  This is activity since April 2019 for NMSZ.  92 total earthquakes.  Activity has certainly ticked up as of late.  Hopefully they stay weak like this!

[mamMATTus]

Several small quakes in the Reelfoot Lake/Ridgely area over the last 24 hours.

[Thundersnow]

Several small quakes in the Reelfoot Lake/Ridgely area over the last 24 hours.

Interesting. I don’t have the fault system layout in front of me- but that’s right around the intersection point of two legs of the fault zone in terms of where events are recorded along linear axes.... one that is oriented NE to SW and the other oriented NW to SE.

[bugalou]

Interesting. I don’t have the fault system layout in front of me- but that’s right around the intersection point of two legs of the fault zone in terms of where events are recorded along linear axes.... one that is oriented NE to SW and the other oriented NW to SE.

It makes a tilted backwards "Z" with what you are talking about being the southern vertex. 



There are vertically large plutons (huge monolithic chunks of igneous rock) on the western side of these faults that are sinking into the mantle at a greater rate than the surrounding crust.  This is what puts the stress on the fault system and why there is no trackable movement of the fault at the surface.  There have been some recent studies showing some slow vertical movement upwards on Crowley's ridge but the mechanisms in play are not well understood at this time.  This may allude to it being involved some how in the system and not just an left over alluvial island as previously proposed.  That said that is on the bleeding edge of research and hotly contested.

Areas shaded are the maps of the plutons:


There is also a newly found fault that runs parallel to the reelfoot rift shown above, but about 50 miles to the south and runs under the MS river around Memphis. It can and has cause quakes but is much more quiet than the fault to the north.

[Thundersnow]

I always thought Crowley’s Ridge was an interesting feature. It’s such a linear ridge that rises out of the alluvial plain. It’s an interesting thing to come across when driving across the flatness of eastern AR.

I recall reading theories about it anything from a “bank/bluff” left over from some ancient placement of the river system to perhaps some effect of the NMFZ.

[bugalou]

I always thought Crowley’s Ridge was an interesting feature. It’s such a linear ridge that rises out of the alluvial plain. It’s an interesting thing to come across when driving across the flatness of eastern AR.

I recall reading theories about it anything from a “bank/bluff” left over from some ancient placement of the river system to perhaps some effect of the NMFZ.

The current accepted theory is the MS river us to flow west of it and then moved east and this was just the only un-erroded portion of t he land life.  There is species of plants and animals there that are the same or related to species in east TN and northern AL so that backs up the theory.  The part that ties into the NMFZ is speculation if this was a naturally high area some how related to it, or if it was just leftover from some period in the past and has nothing to do with it.

[Thundersnow]

I also remember that about the wildlife... apparently the flora and fauna on the ridge have more in common with the hills of TN than they do the nearby Ozarks.

[Curt]

I also remember that about the wildlife... apparently the flora and fauna on the ridge have more in common with the hills of TN than they do the nearby Ozarks.

It’s the ONLY  place in Arkansas that has a deciduous cover that’s related an Appalachian deciduous that stops at the MS River.