The article claims that a nine-megaton blast would wipe out "most of the state of Arkansas". Wikipedia claims the lethal radius on a bomb of that size is about 20 miles for thermal effects (http://en.wikipedia.org/wiki/B53_nuclear_bomb#Effects ), which is around 2% of the area of Arkansas; other effects are described as having an even smaller radius.
I suspect, but cannot prove, the wikipedia number is more likely to be correct.
Fall-out effects from such a large & dirty H-bomb detonated at ground level would have been pretty bad - you wouldn't want to be downwind of such an event.
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Actually, if you consider the indirect effects of the use of such a weapon - particularly the large number of refugees fleeing contaminated areas, huge numbers of injured etc. while such a detonation wouldn't destroy an entire state it would probably reduce it to complete chaos.
e.g. The UK government estimated in the 1950s that three H-bombs would be all it would take to destroy the UK as a functioning society - the UK ambassador in Moscow even had a drunken debate with Kruschev on this point - suggesting that the hundreds of weapons the Soviets had pointing at the UK were complete overkill...
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The UK government was always pretty gloomy/realistic about the likely impact of a nuclear war on the UK - basically even in fairly optimistic scenarios such as the Square Leg exercise used as the basis for Threads were absolutely awful. A real attack would have been far worse that the one shown in Threads, if anyone can conceive of that.
>> suggesting that the hundreds of weapons the Soviets had pointing at the UK were complete overkill...
As Schlosser says in his book - because of the lack of coordination between the Air Force, Army, US Navy and Missile Forces, at one point there was something like 400(sorry if I remembered the number wrong,but it was in hundreds) nuclear rockets aimed at Moscow, many of them with multi-megaton payload. If they were launched, Moscow wouldn't be just destroyed - the entire area would be turned into the biggest crater on earth.
A point that bears repeating is that this level of overkill was actually counterproductive. One way of disabling a high efficiency nuclear device is to blast the thing with neutrons (causing a premature and incomplete fission reaction in the core of the weapon). This was actually how the Sprint ABM system was intended to destroy its targets:
Now picture the skies over Moscow with ~400 warheads coming in, most of them having been launched in a coordinated wave by Minuteman, Titan, or MX missiles within the space of a few minutes: it turns out that the prompt neutron pulse, blast, EMP, or thermal effects from one incoming warhead can disrupt another if it arrives within 10 seconds of the first. This is termed nuclear fratricide:
One explanation of the massive overkill that the US had for a lot of the Cold War came down, essentially, to badly stated requirements.
Apparently, the US military were tasked with destroying 50% of the socialist world's industrial capacity - which you could do by destroying 50% of the factories completely or 100% of the factories by at least 50%. However, if you attack say a shoe factory (the example given) with an H-bomb aiming to achieve at least 50% destruction you do actually get 100% destruction. So all factories were targeted.
NB I used the phrase "socialist world" as, at least until well into the 60s, the SIOP aimed to destroy everyone even vaguely left of center whether they were actually allies of the Soviets or not (e.g. China, Albania, Yugoslavia etc.).
Pretty sure I read this in "The Bomb - A Life" by Gerard DeGroot, but I could well be wrong!
Maybe, but another important reason for overkill is that you couldn't be sure that all payloads would actually reach their destination. In the nuclear-bomber era this was especially the case - IIRC the last book I read on LeMay suggested that planners assumed around 90% of the planes would be shot down far away from their intended targets. The missile era obliterated that particular dynamic, but replaced it with a threat against second-strike capability from your enemy's ICBMs.
Most of the politics at that time wildly overestimated the capabilities of the Soviets in public (hence the infamous bomber and missile gaps) while internally having pretty accurate and poor estimates of their capabilities - LeMay at one point expected that the SIOP could be implemented with pretty low levels of casualties.
Air defence systems back them were really pretty poor - e.g. the infamous case where the entire US air defence system couldn't stop UK strategic bombers taking out major us cities in an exercise (which was kept quiet for decades due to the embarrassment it caused).
"It appears that two weapons targeted on a silo must arrive at least 10 s apart to avoid fratricidal fireball effects, and less than 1 min or more than 1 h apart to avoid fratricidal nuclear dust cloud effects."
Anyone for Missile Defense with a 50-100Mt Tsar bomba?
A primary reason for the generally larger, and in some cases, insanely large throw-weights of Soviet nuclear missiles was their much less accurate targeting and guidance systems.
If you can land a nuke, or even a conventional warhead, directly on whatever it is you're trying to make a was, your required explosive yield falls dramatically.
Blast radius and damage increases with the cube of yield, so if you're half as accurate, you need 8x the blast, generally, for effective damage.
Turns out that with extremely high precision warhead delivery, the US can dispense with nuclear weapons even for tasks such as destroying deeply buried and reinforced bunkers (command and control, or missile launch).
On the one hand this makes nuclear Armageddon that much less likely. On the other it makes use of highly advanced weaponry less objectionable.
Which way the risk needle ultimately swings given that calculus is an interesting question.
I remember the figure of 400 as well - don't know if that included UK weapons as well (e.g. the Chevaline upgrade to Polaris was mainly about defeating the ABM defenses around Moscow).
NB An interesting article by Charlie Stross on the relationship between the US and the UK's "independent" deterrent:
I don't think anyone knows what would happen to an area after 400 detonations.
My (wild) guess is that you'd get a blob of extremely hot rock melting its way down through the crust and enough fallout to sterilise the Northern hemisphere.
So kind of a dumb idea from a strategic point of view.
It is, but that's the problem - Air Force, Army,Navy and SAC controlled their own missiles and apart from the fact that they would all launch theirs if they got an order from the president, they didn't coordinate when it came to which targets each one of them would hit. So the Air Force might have had a plan to hit 100 points around Moscow, and so did the Army,and so did the Navy,and so did the SAC. So at the moment of launch 400 rockets would be hitting the same spot,because the attack would not be coordinated.
The risks of having an uncoordinated attack were known pretty early on - e.g. having bombers blowing each other up, bombers destroyed by missile attacks etc. That's why there was the SIOP:
Another technical mistake in the New Yorker article: it implies that since the missle was armed, the fire could have produced a megaton-sized blast. Not true: the component that undergoes fission in all US nukes designed after 1945 is spherical, and for the component to release significant amounts of energy, the sphere has to be compressed by a very precisely-timed combination of about 20 explosions of conventional explosives (TNT or such). In fact, a new kind of electronic device needed to be invented by the Manhattan Project to meet the precise timing demands.
So, although it is possible for the fire to ignite the conventional explosives, it would almost certainly have not done so in precisely the way needed to activate the atomic components of the bomb -- at least that is what I have read somewhere. (Sorry, I do not remember where -- maybe Carey Sublette's Nuclear Weapons FAQ.)
The worst thing that could realistically have happened is that the fire and a conventional explosion would have spread the radioactive components of the bomb (particularly, plutonium) into the environment, in the manner of a dirty bomb.
Your comment assumes that the weapon was one-point safe, which was not true for all US devices. I cannot remember the source but apparently for many years (through at least the 80's, I believe) many US weapons could have produced a yield if subjected to a fire.
Suppose the trigger device providing the precise timing could misbehave at high temperatures. Or, in the same source I mentioned earlier, it was disclosed that there were wiring paths which could have melted together in a fire and cause the weapon to fire.
Castle Bravo [1], [2] was a 15Mt yield set off on Bikini Atoll, notable because it was predicted to be 6Mt but was almost 2.5x that. Considering how much of the Bikini Atoll is left ([3], with pin on the location of detonation) and that the command centre for Castle was on the Atoll, I'd say that Arkansas is ok.
You could live there, it just isn't a very good place to live anymore. You would need to fly in your own food and water, and you'll still be getting irradiated, but we're talking "probably get cancer one day" irradiated, not "die of radiation sickness" irradiated.
Bikini Atoll was also worse than this hypothetical Arkansas scenario in two ways:
1) The soil there is potassium poor, causing local plants to more readily take in radioactive cesium.
If by "wipe out" the author meant create a lot of casualties and do immense property damage and by "most of the state" the author was talking about population and infrastructure value and not surface area, it's a very defensible statement. The central part of the state is pretty densely populated and that bomb is large.
edit: for starters consider that in a state of three million people, 725k are in Little Rock, which is only 116 square miles. Then read the specs on that bomb you linked to again.
>I suspect, but cannot prove, the wikipedia number is more likely to be correct.
The Wikipedia number is not correct, because even a single blast has long term consequences, and in a full scale war, the consequences are more significant than the initial damage.
Even if the blast was just one a of a handful, survivors would have to contend with fallout from other detonations, followed by nuclear winter, followed by years of famine, mutation, cancer, and other diseases.
In a full scale war, nukes are targeted at nuke power plants, so there would be even more fallout - enough to sterilise many parts of the US.
Initial casualties would be a small percentage of the eventual total.
Even a limited exchange in a distant part of the world would have global consequences. See e.g.
> "in a full scale war, the consequences are more significant"
The specific point being discussed was a local disaster -- a 9 megaton bomb which was damaged by somebody dropping a tool on it -- not an all-out war scenario.
Which is why I responded the way I did. In that scenario, I don't see any realistic case in which the entire state of Arkansas would be "wiped out". Possibly fallout would have rendered a fraction of the state uninhabitable for several weeks, and possibly some long-term effects would render a smaller fraction of the state uninhabitable for much longer, but the whole state "wiped out" is just sloppy journalism.
No, see the answer from aeturnum: use the online calculator, enable falout. You'll have to zoom out the map: the area of the effects is approximately as big as the state.
I did in fact already run this scenario. The fallout area is large if you set the threshold low enough. But from what I understand, the largest rings do not render the area uninhabitable by any means. Perhaps the smallest inner ring does. Fallout is also generally a short-term effect -- weeks, not decades.
Also be aware that fallout from an underground blast (as in a silo) is going to spread much differently from fallout from an airburst.
Contrary to what you assume, the fallout increases in the underground burst compared to the burst in the air as the surface is reached see: http://fas.org/nuke/intro/nuke/effects.htm
I'm not trying to assume. I'm trying to research. I read that page, and several others. From what I understand, the local fallout (ie, within a few mile radius) is much higher in subsurface bursts, but the longer-range fallout is substantially less.
Thus, I am unconvinced by the argument that the longer-range fallout would "wipe out" something the size of Arkansas.
I suspect, but cannot prove, the wikipedia number is more likely to be correct.