Driftless
Donor
The US dodged a very destructive bullet with the New Madrid Earthquakes of 1811-12. The area was comparatively sparsely populated and developed when the quakes hit. If they hit even 50 to 75 years later, the damage and loss of life would have been catastrophic.
Earthquake. Enough said.
(snip)
But yes, the New Madrid Fault is basically a ticking time bomb, assuming the theory where the fault was extinct after 1812 and all quakes on the fault since then are merely aftershocks is false. Though I've never heard the Mississippi Delta is vulnerable to quakes as much as Memphis and further north.
(snip)
It would've been better if those quakes had hit then instead of in 1811-1812. The local government would have some clue as to planning for the disaster and most important future disasters as well as the potential for damage quakes can cause. The Eastern United States has a specific geology which amplifies earthquake waves, as seen in the 2008 Illinois earthquake (I was over 150 miles from the earthquake, and felt the ground shaking, and thought it was a dream, and hours later, people were talking about the earthquake), or the 2011 Virginia earthquake. Memphis politicians, corrupt as New South Memphis was, might've planned for it, and hopefully with their influence on the rest of Tennessee dragged Nashville and the rest of the state along with it. Basically, a 7.0 New Madrid quake will cause far more damage over a larger area than an equivalent 7.0 San Andreas quake would cause.
Right now, Memphis, Tennessee has minimal plans regarding a major quake (Nashville has even less, I don't know about other major cities). Few buildings are built to code. The state of Tennessee has people working on it, but it's a small committee which has other jobs (some are college professors in state universities, and they have minimal influence). I'm not sure of the situation in Paducah, St. Louis, or elsewhere in the danger zone. If a quake happened, and the Mississippi River was affected as in 1812 (it ran backwards, formed Realfoot Lake, etc.), West Tennessee would be mostly cut off. The highways (Interstate 40) would be wrecked and in need of repair, as would the back roads, the airports (Memphis as a freight hub would be wrecked) likewise, the Mississippi unnavigable (that will have huge impact on more than just the Lower Mississippi region). I'm pretty sure that Little Rock, St. Louis, Paducah, Nashville, Clarksville, and most major cities near the fault zone will all have significant damage as well and tie up emergency responders. It will be very difficult to get the emergency supplies to where they are needed, and you are dealing with an unprecedented national disaster.
California is relatively well-prepared for this, as bad as "The Big One" would be for that state. I'd rate New Madrid Part 2 as number two on worst disasters to potentially hit the US, right behind 1700 Cascadia Earthquake Part 2 (which has devastating effects both regional and global). Now, since I live in Middle Tennessee (disaster zone), I might be biased, but outside of something like Yellowstone erupting, it's hard to think of a worse disaster which affects such a large region. The effects of this will run into hundreds of billions of dollars in damage.
And while you're at it, have this earthquake strike in February/March, so you're just in time for the South's late winter/spring weather, which includes snow, freezing rain, days of nothing but rain (and mild or worse flooding), severe thunderstorms, and why not have a major tornado outbreak strike the same region, since that's what happens from February to May in the South. You can even have multiple tornado outbreaks strike within a few weeks of each other, since that's how the climate works.
The following point is decidedly a tangent from the original post....
There's a Point-of-departure for an ASB timeline (geologic event). Move the New Madrid Earthquakes to 1862-63, coinciding with the campaigns for the control of the Mississippi during the American Civil War. That's a very pivotal series of battles drawn out over a year. The quake itself would pose issues, but the impact on the river and it's immediate environs, plus the impact on cities in the region would likely change the course of the campaign.