If a big one hits, the damage to these two cities, especially Memphis, will be catastrophic and possibly will be the worst disaster in history up to that point. And I misspoke: It's not "if" it happens, it's "when" it happens. When the land stops shaking, what will be done with the rubble? All 4 Memphis bridges will have to be rebuilt. Highways like I-40, I-55, and I-69 might have to be completely relocated and rebuilt from scratch. If Memphis is nothing more than a wasteland and an post-civilized battlefield, will they route I-40 up Sam Cooper and through the former Overland Park? I have a feeling that Memphis will be especially hard hit, with massive soil liquification and rerouting of the Mississippi River. A bad quake would destroy major cities like Blytheville, Jonesboro, Cape Girardeau, and Piggott. So how would the road system be changed after a catastrophic New Madrid Earthquake?
The economic impact from these vital connections being severed will be huge, too.
Not only the roads, but also the railroads will be severed as well as well as gas and oil pipelines. I-70 and I-20 might be impacted as well and the shock might be fell as far north as Chicago and Milwaukee. Depending if it'll hard as the Earthquake of 1812 http://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone
And the Mississippi river rerouting, would the quake enough powerful to divert some part of the Mississippi waters into Lake Michigan via the canals linking Lake Michigan to the Illinois River?
Memphis is closer to the fault line than St. Louis, and Memphis would likely be hit harder. This area is long overdue for a major earthquake to happen, as the last large one happened back in the 1960s
Quote from: Stephane Dumas on April 23, 2012, 01:44:43 PM
And the Mississippi river rerouting, would the quake enough powerful to divert some part of the Mississippi waters into Lake Michigan via the canals linking Lake Michigan to the Illinois River?
Any rerouting of the Mississippi is only going to involve the channel shifting east or west a little (mile or so) and only over a short segment. There is absolutely no way you could permanently reverse the flow of a river with just one quake. It can happen temporarily because the quake opened a fissure and water poured in or an area of land is thrust up or down causing the stream to shift channels and drain the old channel. But in a flat, alluvial landscape like the lower Mississippi, even the biggest earthquake is only going to generate localized alterations to the hydrography.
So any changes in streams and drainage will be confined to the local area of the fault that slips. Also, they will only happen if one of the thrust faults in the New Madrid area is the one that goes. There are also strike-slip faults in the area and those don't deform the land surface nearly as much.
Nothing short of another ice age is going to alter the destination of tributaries of the Mississippi.
Quote from: triplemultiplex on April 23, 2012, 02:40:47 PM
Quote from: Stephane Dumas on April 23, 2012, 01:44:43 PM
And the Mississippi river rerouting, would the quake enough powerful to divert some part of the Mississippi waters into Lake Michigan via the canals linking Lake Michigan to the Illinois River?
Any rerouting of the Mississippi is only going to involve the channel shifting east or west a little (mile or so) and only over a short segment. There is absolutely no way you could permanently reverse the flow of a river with just one quake. It can happen temporarily because the quake opened a fissure and water poured in or an area of land is thrust up or down causing the stream to shift channels and drain the old channel. But in a flat, alluvial landscape like the lower Mississippi, even the biggest earthquake is only going to generate localized alterations to the hydrography.
So any changes in streams and drainage will be confined to the local area of the fault that slips. Also, they will only happen if one of the thrust faults in the New Madrid area is the one that goes. There are also strike-slip faults in the area and those don't deform the land surface nearly as much.
Nothing short of another ice age is going to alter the destination of tributaries of the Mississippi.
Or the colapse of the Old River Control Structure and/or Morganza Control Structure down in Louisiana.
Quote from: Hot Rod Hootenanny on April 23, 2012, 08:47:03 PM
Quote from: triplemultiplex on April 23, 2012, 02:40:47 PM
Quote from: Stephane Dumas on April 23, 2012, 01:44:43 PM
And the Mississippi river rerouting, would the quake enough powerful to divert some part of the Mississippi waters into Lake Michigan via the canals linking Lake Michigan to the Illinois River?
Any rerouting of the Mississippi is only going to involve the channel shifting east or west a little (mile or so) and only over a short segment. There is absolutely no way you could permanently reverse the flow of a river with just one quake. It can happen temporarily because the quake opened a fissure and water poured in or an area of land is thrust up or down causing the stream to shift channels and drain the old channel. But in a flat, alluvial landscape like the lower Mississippi, even the biggest earthquake is only going to generate localized alterations to the hydrography.
So any changes in streams and drainage will be confined to the local area of the fault that slips. Also, they will only happen if one of the thrust faults in the New Madrid area is the one that goes. There are also strike-slip faults in the area and those don't deform the land surface nearly as much.
Nothing short of another ice age is going to alter the destination of tributaries of the Mississippi.
Or the colapse of the Old River Control Structure and/or Morganza Control Structure down in Louisiana.
I spent a couple hours looking at that system up close a few years ago, it's a magnificent feat of engineering. But one has to think that the river can't be held back forever.
Well, IMHO, the next 'Big One™' from the New Madrid fault zone will likely cause widespread non-catastrophic damage in Chicagoland (major tall building sway, non-structural damage to masonry buildings, items falling off of walls and shelves, etc), will be very noticeable with minor damage in Milwaukee and certainly be felt here in Appleton, WI.
Rail freight traffic can certainly be rerouted away from that region and I can easily see the USArmy CoE quickly setting up temporary pontoon bridges to restore road crossings of the Mississippi River in the fault zone area.
Mike
I've also heard of the possibility that a "relay" quake along the New Madrid could have an effect places all along the Great Lakes and Ohio River, such as Louisville, Cincinnati, Chicago, Cleveland, and Buffalo.
A $100 million museum in Union City, TN (http://www.commercialappeal.com/news/2013/feb/16/union-city-discovery-park-of-america/?partner=popular) will soon have a theater that will simulate the "sights, sound and shock" of the 1811-12 earthquakes:
Quote
To build Discovery Park of America, this rural community is spending the money of a retired businessman, tapping the brainpower of 250 citizens comprising 25 committees, and using the nation's and Memphis's leading museum architects, exhibit developers and landscape architects.
An October opening is planned for a museum-like complex that would befit Chicago's lakeshore or Central Park's border.
One theater will make visitors feel they're on the bridge of a spaceship, traveling the universe via a wrap-around screen showing real outerspace images.
Another theater will recreate the sights, sounds and shock of the severe New Madrid earthquakes of 1811-12, which formed the nearby Reelfoot Lake.
Other "wow" factors: A hologram of a storytelling Native American; a five-foot-diameter, 3D globe that shows everything from shifting continents to current weather systems; a 50-foot, stylized sculpture of a human body whose left leg doubles as a kids' slide; a 20,000-gallon aquarium visitors can walk into; airplanes suspended high in a vast atrium; $2 million-$3 million in newly acquired antique vehicles; dynamic floor tiles that create the illusion you're falling into the abyss; and the signature architectural piece – a tower with a glass-enclosed observation deck 120 feet tall topped by a flagpole 200 feet high.
Quote from: Grzrd on February 18, 2013, 07:48:08 PM
A $100 million museum in Union City, TN (http://www.commercialappeal.com/news/2013/feb/16/union-city-discovery-park-of-america/?partner=popular) will soon have a theater that will simulate the "sights, sound and shock" of the 1811-12 earthquakes:
Quote
To build Discovery Park of America, this rural community is spending the money of a retired businessman, tapping the brainpower of 250 citizens comprising 25 committees, and using the nation's and Memphis's leading museum architects, exhibit developers and landscape architects.
An October opening is planned for a museum-like complex that would befit Chicago's lakeshore or Central Park's border.
One theater will make visitors feel they're on the bridge of a spaceship, traveling the universe via a wrap-around screen showing real outerspace images.
Another theater will recreate the sights, sounds and shock of the severe New Madrid earthquakes of 1811-12, which formed the nearby Reelfoot Lake.
Other "wow" factors: A hologram of a storytelling Native American; a five-foot-diameter, 3D globe that shows everything from shifting continents to current weather systems; a 50-foot, stylized sculpture of a human body whose left leg doubles as a kids' slide; a 20,000-gallon aquarium visitors can walk into; airplanes suspended high in a vast atrium; $2 million-$3 million in newly acquired antique vehicles; dynamic floor tiles that create the illusion you're falling into the abyss; and the signature architectural piece a tower with a glass-enclosed observation deck 120 feet tall topped by a flagpole 200 feet high.
If you've ever been to Union City, the first question that would come to your mind is, "What on earth is there to see from an observation tower?"
rte66man
Quote from: Stalin on April 23, 2012, 04:13:15 AM
If Memphis is nothing more than a wasteland and an post-civilized battlefield, will they route I-40 up Sam Cooper and through the former Overland Park?
BTW, it's Overton Park in Memphis, not Overland Park, which is a KC suburb.
Quote from: Speedway99 on February 19, 2013, 06:26:24 PM
Quote from: Stalin on April 23, 2012, 04:13:15 AM
If Memphis is nothing more than a wasteland and an post-civilized battlefield, will they route I-40 up Sam Cooper and through the former Overland Park?
BTW, it's Overton Park in Memphis, not Overland Park, which is a KC suburb.
Typo. I used to work in Overland Park, so I was probably thinking of it.
The Geologists have changed their risk maps a few times. I can tell you the ionsuracne companies changed their assesments. I am in Central Illinois and my Earthquake insurance went up from 25 dollars a year to 185 in just the last few years
Quote from: tidecat on May 14, 2012, 10:40:22 PM
I've also heard of the possibility that a "relay" quake along the New Madrid could have an effect places all along the Great Lakes and Ohio River, such as Louisville, Cincinnati, Chicago, Cleveland, and Buffalo.
Basically, due to the geology of the US east of the Rocky Mountains, an earthquake there can be felt and cause damage as far away as Washington, DC, Boston, or New York.
IL and Mo did a Seismic Retrofit on the PSB some years ago. I saw it in an IDOT 5 Year plan.
IDOT like Joe operates on a 5YP
Memphis is built on a bluff, so it should withstand the quake better than the Arkansas side, which is alluvial soil that will turn to jelly. The flatlands are where the greatest effects will be. That's not to say Memphis won't suffer extensive damage. There's not much you can do in an 8.0.
Reelfoot lake in NW Tenn was created from the earthquake as it shifted the Mississippi River. A quake like that these days would do damage in the Hundreds of Billions.
The "big one" on the New Madrid fault would be devastating. I-40 is so heavily traveled as the main East-West trucking route that we might see economic impacts across the country for a long while.
Plus, with the composition of the soil & rock under the soil, the shock waves could impact all of Arkansas. I live in Little Rock & it would nail us.
Quote from: Stephane Dumas on April 23, 2012, 01:44:43 PM
Not only the roads, but also the railroads will be severed as well as well as gas and oil pipelines. I-70 and I-20 might be impacted as well and the shock might be fell as far north as Chicago and Milwaukee. Depending if it'll hard as the Earthquake of 1812 http://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone
And the Mississippi river rerouting, would the quake enough powerful to divert some part of the Mississippi waters into Lake Michigan via the canals linking Lake Michigan to the Illinois River?
As I recall, aren't there really only
four railroad bridges between St. Louis and Baton Rouge?
1. Thebes(IL)-Illmo(MO) bridge just south of Cape Girardeau...links the Union Pacific Chicago and St. Louis lines to the boot heel and therefore the directional Texas lines via Poplar Bluff (northbound traffic) and Jonesboro (southbound) plus UP Louisiana. CSX and predecessor Conrail ran/run their North Little Rock - Indianapolis and
vice versa trains over this bringing Michigan/Ohio/mid-Atlantic/New England traffic through to Texas and Louisiana. (HEAVILY used)
2. Memphis. (The parallel by a few yards Frisco and Harahan bridges - 'nuff said - HEAVILY used with UP/BNSF interchange with CN/CSX/NS)
3. Vicksburg (Kansas City Southern's "Meridian Speedway", heavily used and THE connection between Dallas/Fort Worth and Atlanta, heavily financed by NS as well.)
If a big quake hits down there that destroys Memphis the Thebes bridge will likely be affected as well. Don't know about Vicksburg. Imagine, though, if the only rail connections over the lower Mississippi were severed at all points between St. Louis and Vicksburg (or Baton Rouge, though I think that unlikely, hopefully)...if "St.Louis-Vicksburg", that would leave almost 500 miles of Mississippi River without a working railroad bridge. :-( (That said, I do think a lot of if not all the Thebes traffic could be routed along UPs current northbound-directional line south from St. Louis to Poplar Bluff...BOY would it choke that line, though. (Remembering what happened when UP and SP did their merger around 1997, seeing trains stopped seemingly every five miles between Bossier City, Lewisville and Pine Bluff along the old "Cotton Belt".))
According to AHTD maps, there was once a rail ferry at Helena, AR. The current maps don't show it, so I assume it was closed.
Quote from: bugo on March 11, 2013, 07:57:56 PM
According to AHTD maps, there was once a rail ferry at Helena, AR. The current maps don't show it, so I assume it was closed.
In 1972: http://cs.trains.com/trn/f/507/t/42151.aspx
There used to be a bunch of rail ferries on the Mississippi (including some not in this list); the last was apparently at Natchez-Vidalia (1982). If the bridges were taken out of service, they'd be the best bet for quick restoration of service. The main issue is getting trains down the bluffs to river level; this was usually done with steep inclines.
The ferry was shown on the AHTD maps up into the '80s. Just a mapo, I'm sure.
Quote from: NE2 on March 11, 2013, 09:07:33 PM
Quote from: bugo on March 11, 2013, 07:57:56 PM
According to AHTD maps, there was once a rail ferry at Helena, AR. The current maps don't show it, so I assume it was closed.
In 1972: http://cs.trains.com/trn/f/507/t/42151.aspx
There used to be a bunch of rail ferries on the Mississippi (including some not in this list); the last was apparently at Natchez-Vidalia (1982). If the bridges were taken out of service, they'd be the best bet for quick restoration of service. The main issue is getting trains down the bluffs to river level; this was usually done with steep inclines.
Couldn't re-use the Natchez-Vidalia rail ferry crossing without reconstructing a hundred or so miles of rail line that it formerly served on the Louisiana side of the river. The rail lines from Vidalia to Ferriday and north and west from there have been gone since at least the late 1980s. The rights of way may still be available, though.
I imagine similar issues may be in play for other former rail ferry crossings.
Quote from: Urban Prairie Schooner on March 12, 2013, 01:41:52 PM
I imagine similar issues may be in play for other former rail ferry crossings.
They'd put in a quick and dirty temporary ferry near the site of the damaged bridge.
It won't just be the Mississippi River bridges that will be destroyed. Many overpasses will collapse as well. Roads will buckle, and rail lines will be damaged in many places. The shit is going to hit the fucking fan with this one, folks. It's going to be much worse than anybody is expecting.
Quote from: NE2 on March 11, 2013, 09:07:33 PM
Quote from: bugo on March 11, 2013, 07:57:56 PM
According to AHTD maps, there was once a rail ferry at Helena, AR. The current maps don't show it, so I assume it was closed.
In 1972: http://cs.trains.com/trn/f/507/t/42151.aspx
There used to be a bunch of rail ferries on the Mississippi (including some not in this list); the last was apparently at Natchez-Vidalia (1982). If the bridges were taken out of service, they'd be the best bet for quick restoration of service. The main issue is getting trains down the bluffs to river level; this was usually done with steep inclines.
Hadn't thought about that. I think there's actually a small tunnel right in Vicksburg on the KCS line. Knowing how far above water the decks of these Mississippi River bridges have to be (as opposed to, say, the Arkansas, where the Union Pacific northbound-traffic St.Louis/Chicago - Texas mainline at Little Rock has had water lapping though not overtopping the bridge deck on its Baring Cross bridge in times of major flooding) if the opposing shore embankments collapse I should think those would be not easy to restore (though some engineers may easily prove me wrong)...as it is those will almost be the least of our concerns.
And as far as things "hitting the fan" you're right. Back around 1990 there was a (made-for-TV?) high budget film about a devastating future earthquake in Los Angeles. Bear in mind, CGI effects were still primitive compared to today, but the producers originally wanted the movie to take place in Memphis. After research, they concluded: "No, we can't replicate the effects of what will happen there when the NM fault blows."
I live in Bella Vista, AR where there apparently is a fault on the east side of the village. But every time I feel the ground shake (as it did twice during the Prague, Oklahoma quakes of 2011) I'm concerned that something has happened 300 miles east.
I felt 3 earthquakes in 2011. It felt like my building was being shaken apart. They lasted for about 45 seconds.
Engineered long-span bridges are usually less of a problem than the many, many ordinary buildings. The midwest will be hit hard, because building codes have not been written with earthquakes in mind until recently, if at all.
Quote from: rte66man on February 19, 2013, 05:27:18 PM
If you've ever been to Union City, the first question that would come to your mind is, "What on earth is there to see from an observation tower?"
rte66man
The below photograph from this May 7 article (http://www.nooga.com/161419/a-sneak-peek-at-discovery-park-of-america/) gives a good sense of the view:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FVhuVpx5.jpg&hash=bb62cb1c23183007c3fbc31e5ea58663da2e3ea1)
Quote from: Grzrd on May 14, 2013, 10:34:45 AM
Quote from: rte66man on February 19, 2013, 05:27:18 PM
If you've ever been to Union City, the first question that would come to your mind is, "What on earth is there to see from an observation tower?"
rte66man
The below photograph from this May 7 article (http://www.nooga.com/161419/a-sneak-peek-at-discovery-park-of-america/) gives a good sense of the view:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FVhuVpx5.jpg&hash=bb62cb1c23183007c3fbc31e5ea58663da2e3ea1)
Nice photo, but I still don't know what there is to see. I doubt it's tall enough to see to Reelfoot Lake.
rte66man
Probably a couple Ohio River crossings too. The old cantilever near Cairo (and the near identical one that crosses the Mississippi a mile to the west) both immediately come to mind. I'm scared shitless on bridges like that anyway.... an earthquake probably brings both of those down easily.
^ This June 2011 study (http://www.southerngatewayproject.com/library/CP-1%20Package%20with%20Agency%20Lts%20and%20Responses.pdf) discusses which bridges may collapse if there is another "big one" (page 22/112 of pdf; page 18 of document):
Quote
North of Memphis:
- I-155 in Dyersburg, Tennessee (75 miles north of Memphis) — This bridge is likely to collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ.
- US 60/US 62 in Birds Point, Missouri and Cairo, Illinois (150 miles north of Memphis) — This bridge is likely to collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ.
- I-57 in Charleston, Missouri, and Cairo, Illinois (156 miles north of Memphis) — This bridge is a four-lane structure that would likely remain after a major seismic event and would have to be paired with a bridge over the Ohio River to provide an alternate detour route. Possible bridges over the Ohio River that have a reasonable probability of remaining are the US 51 bridge located between Cairo, Illinois, and Wickliffe, Kentucky, or the I-24 bridge between Metropolis, Illinois and Paducah, Kentucky.
South of Memphis:
- US 49 in Helena, Arkansas (70 miles south of Memphis) — This bridge is likely to collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ.
- US 82 / US 278 in Lake Village, Arkansas and Greenville, Mississippi (145 miles south of Memphis) — This bridge is a recently constructed four-lane bridge that was designed to the appropriate seismic design criteria.
In Memphis itself (pages 16-17/112 of pdf; pages 12-13 of document):
Quote
BNSF's Frisco Bridge — The Frisco Bridge will probably collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ ....
Union Pacific's Harahan Bridge — The Harahan Bridge will probably collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ ....
TDOT's I-55 Bridge - The I-55 Bridge will probably collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ ....
TDOT's I-40 Bridge — The newest and most robust of the Memphis bridges, the 1973 Hernando DeSoto Bridge, is currently in the final stages of a seismic retrofit project designed to withstand an earthquake up to magnitude 7.7. It is expected that the bridge will be available for emergency responders and other aid workers immediately following a severe earthquake in the NMSZ. Of the four Memphis area bridges, the I-40 Bridge has the greatest chance of surviving an earthquake of the same magnitude as the 1811-1812events.
Powerful find, Grzd.
Also from the document, on page 23/112 (regarding railroad traffic rerouting in the event of the aforementioned bridge collapses):
Quote
To determine the level of disruption and diversion caused by a closure of the rail bridges at Memphis, interviews were conducted with personnel from the two railroads that operate the UP and BNSF bridges. Both of these rail carriers provided their emergency contingency plans for a bridge failure summarized as follows:
- UP: Divert rail traffic from Memphis to Salem, Illinois (interchange with CSX) and New Orleans (interchange with CSX, NSRR, CN).
- BNSF: Divert rail traffic from Memphis to Vicksburg, Mississippi (with CN) and Paducah, Kentucky (with CN).
It is estimated that rail diversion to the alternate routes would cause supply disruptions between 3 to 10 days per shipment due to additional handling and switching. If the bridge failures were due to a seismic event, the delays would be longer since the northern diversion routes would likely be damaged by the event also.
Tells me that, as mentioned before, they're expecting the older Thebes UP railroad bridge (crossing the Mississippi River just south of Cape Girardeau - on the map on page 23 it's represented along the next thickest line which parallels the Mississippi at the Missouri/Illinois border before entering into northeast Arkansas) to collapse or at least be seriously damaged as well. And though the map on page 23 doesn't show it, I know that for the longest time there's been an significant exchange of railcars between Indianapolis (receiving freight from the east side of the Midwest plus the Northeast) and the UP yards at North Little Rock via the (current) CSX, to the UP at St. Elmo, IL (after the UP mainline from Chicago joins the CSX at nearby Altamont), then southward over the Thebes bridge to North Little Rock.
Translation: in the event of a major New Madrid quake there will be no railroad bridges for a while between south of St. Louis and north of Vicksburg, and if the St. Louis bridges are damaged the northerly limit might be either Bowling Green, MO or Fort Madison, IA. That's at best (south of St. Louis) a near-450 mile as-the-crow-flies chunk of territory.
That big quake will not only damage bridges, buildings, roads, railroads but from what I read at http://beforeitsnews.com/science-and-technology/2012/10/imminent-midwest-quake-to-unleash-nuclear-hell-2478270.html nuclear plants located in the area as well. O_o
I know this is a bit "random", but here is a link to the "trainorders" forum discussion about the UP/BNSF train wreck near Chaffee, MO yesterday. (http://www.trainorders.com/discussion/read.php?1,3083632) (All our friends who know highways...the newer bridge for that highway was indeed built DIRECTLY OVER the BNSF St. Louis/Memphis mainline and the aforementioned Union Pacific Chicago/St. Louis/(Indianapolis) - North Little Rock/Texas mainline diamond, where the railroads intersect - a "wye" between the two juts out slightly to the east.)
On this thread they mention how the old Missouri Pacific mainline between Poplar Bluff and St. Louis is now lightly trafficked apart from Amtrak's daily "Texas Eagle" trains. I'm sure the reason is that (as I recall) there are tunnels in the Ozark Mountains highest hills in Missouri in that region, which would either have to be heightened or somehow "daylighted" for the taller trains to run. Which means that unless the UP is doing just that, all their double stack container and auto rack trains must use the aforementioned Thebes bridge (which, sigh, will likely collapse in a significant New Madrid fault event) route. Ouch.
Quote from: Grzrd on May 15, 2013, 11:18:04 AM
This June 2011 study (http://www.southerngatewayproject.com/library/CP-1%20Package%20with%20Agency%20Lts%20and%20Responses.pdf) discusses which bridges may collapse if there is another "big one" (page 22/112 of pdf; page 18 of document):
Quote
North of Memphis:
• I-155 in Dyersburg, Tennessee (75 miles north of Memphis) – This bridge is likely to collapse during an earthquake similar to the 1811-1812 events that occurred in the NMSZ ....
This article about repairs being made to the I-155 bridge (http://www.stategazette.com/story/2224733.html) made me think of this thread because of the understated way it discusses the potential impact of a large earthquake on the bridge:
Quote
The I-155 Caruthersville Bridge is the northernmost bridge over the Lower Mississippi River, with the combined flow of the Upper Mississippi and the Ohio River ....
The Caruthersville Bridge sits in a geologically interesting place in that it is only 6 miles from the New Madrid Fault. A 1993/1994 study found that bedrock was located 2700 feet under the surface, so a significant earthquake event would almost certainly create severe liquefaction. The bridge as it stands would not hold up to liquefaction.
Otherwise, the article has some interesting historical and other information about the bridge.
Flying over Northeast Arkansas in the spring when all the water is gone and the fields are barren, you can see the sand blows all over. For those that know how they formed, it truly is frightening, this ain't your California quake, this is where the land liquifies underneath you like giant quicksand lakes. It's a fear you learn to live with, just like knowing when Blytheville was a SAC base, that the end would be quick via nuke strike.