I always read about how the biggest earthquake in the US happened on the New Madrid faultline. But at that time no one really lived there so damage was minor. Then the stories always go on to say if the quake of that size happend today it would do such and such to St. Louis and Memphis. (Like Keel over the St Louis Arch and Flood Memphis by changing them Mississippi River)
My questions are do St. Louis and Memphis have any plans like the California cities for earthquakes. Like building codes.
What would the effects be to the area if you had a quake similar in size to the SF quake in the late 80s and the Northridge Quake of LA in the early 90s.
As a semi-resident of the area (I’m only living there part-time now,) I’m fairly familiar with the situation. I was in school when Iben Browning made his famous prediction of the Big One in 1993 (he was dead wrong, of course) and there was some discussion about things then.
IME, a good bit of the area doesn’t have specific building codes to address such a quake. Larger cities might, I suppose, but a good bit of the area is still semi-rural.
As for what might happen, let’s take a look at the 1812 quake: it made the Mississippi River run backwards (look up Reelfoot Lake) and rang churchbells in Boston.
No one really thinks that much about it, except for when you get the occasional 3 or 4 tremor that rattles some windows and doors. Tornadoes are a much more common and dangerous threat.
Think of what happened in Iran last year, and Armenia in 1988. Tens of thousands killed by earthquakes that were SMALLER than the Northridge/Loma Prieta quakes.
On the other hand, wood-frame houses have proved to be highly resistant to earthquakes, even if they’re not built to West Coast standards. They may flex and become uninhabitable afterwards, but they rarely collapse. The big danger comes from unreinforced masonry and brick buildings, which are no better than Lincoln Logs when it comes to a big quake. (That’s what caused such massive loss of life in Iran, since all of their houses are basically made of mud.)
On a related note, it’s predicted that a 5.5 earthquake in New York City would completely devastate the city. And it will happen…maybe not for a thousand years, but someday.