Why do the fallout maps I’ve seen of a nuclear attack on the continental USA vary so widely? Other than the obvious- being near a major city or military installation is not good- they don’t even agree on whether a particular area will be spared or heavily irradiated.
My google-fu is hampered by the fact that a popular video game series is named “Fallout”.
I assume because almost every relevant variable will live up to its name and vary, significantly. This would presumably include the weather and wind direction, bombing patterns [how high above ground etc], target priorities, launch sequences and weapon accuracy. Assumptions about the effectiveness of counter-measures might be more or less candid for different audiences.
You may or may not be familiar with NukeMap - which lets you target anywhere you like, and see how different parameters will affect casualties. Its informatively horrible to contemplate.
Care to link the maps you found? Obviously, these maps are going to be based on guesswork, and good ones would require classified data. That is, the CIA probably at one point in the past got a spy to copy the Soviet (and Russian) nuclear war plans. With the actual plans, knowing where each missile is actually targeted, and knowing the megatonnage and type of warhead and assuming a certain attrition rate, you could work out precisely how much fallout to expect. Given certain assumptions about the wind.
For most of us city slickers, myself included, it’s kind of academic. I know I live close enough to a major target that I’m not likely to survive. In your case, well, you thinking about making a fallout shelter on your ranch? I always wondered what the straight dope is on air filtration. I would assume you’d need a source of power that will last several weeks, a HEPA filtered air intake, a decontamination shower, enough supplies for several weeks, a geiger counter with extended range, and something to use as a rad suit. Commonly available Tyvex suits they use for insulating houses would probably be ok as a rad suit, so long as you don’t actually spend much time in the radiation field at the surface.
Anyways, I have the impression that most Cold War era fallout shelters were grossly inadequate. I doubt many of them had a source of power that would be enough for several weeks to run filters. Today, you could do that inexpensively with solar panels and lithium-iron batteries, but back then it would have required a massive quantity of diesel fuel.
Or spare rad suits, or filters, or even geiger counters with adjustable range. They maybe had some food and/or a cellar to hide in. I read that a buried railroad tank car with sealed hatches could let you survive very close to ground zero, assuming you got into the thing and sealed the hatches before the weapons hit.
It takes no guesswork whatsoever to figure out that missile silos, major cities, and important military bases would be targeted. In addition, most areas have prevailing winds–the wind blows from a certain direction a majority of the time.
Sure, there’s enough variables involved to make the figures a bit vague, but it’s nowhere near as imprecise as you suggest.
They were trying to give us hope; it’s as simple as that.
Do you have a cite for that?
The OP’s question is unanswerable until he can show us the maps he’s talking about.
A fallout map will depend on three main variables: What will get hit with what, where the wind is blowing, and where and when it rains. For the first, you can probably make reasonable guesses, but guesses will certainly differ, and the best guesses will (as SamuelA says) be the classified ones.
Now, once you have the fallout generated, you have to figure out where it’s going to go. It’ll mostly follow the winds and gradually settle out, but if it rains, a lot of it will fall out all at once. So you now have to make guesses about the weather. Do you just assume that the winds and rain are all going to follow the prevailing patterns? Maybe, given that a place always getting about the weather expected for the time of year is known to be one of the signs of the Apocalypse. Or maybe you run a weather model where the winds are allowed to vary by about as much as they usually do, get a result for each run, and then sort of blur them all together.
Even from one entity at one time, I’d expect them to make multiple maps for different scenarios. A 500-warhead strike won’t be the same as a 2000-warhead strike, and the typical weather in June isn’t the same as the typical weather in December.* And the maps you saw were probably made by different entities at different times for different reasons. Maybe one was made back in the day when a nuclear strike meant slow bombers dropping dumb bombs, maybe one was a worst-case scenario presented by a civil defense agency during budget time, etc.
*On the maps I found when I looked around, looked like one of the big variables is what direction they assume the wind will blow over the great plains.
I’m only 200 miles downwind from the Mexican border, which is the only country I can think of at the moment that is actually at risk of a nuclear attack.
There are a couple of things that will dramatically affect the fallout that really make the idea of a single prediction useless.
The height of the detonation. Fallout is largely stuff that the bomb picks up off the ground. It isn’t so much stuff out of the bomb, it is stuff on the ground that is intensely irradiated with neutrons, vaporised and lifted into the air. Whether you have a ground detonation, a higher level detonation (for maximum blast damage) or actually a much higher detonation will change the amount of fallout.
Secondly, the intensity of the blast affects how high into the atmosphere the debris goes. A more powerful blast can lift the fallout much higher, and inject it into different winds. You may see the fallout lifted right above the prevailing surface winds and into a higher level stream that is travelling the opposite direction.
Famously the Castle Bravo test (which was a teensy bit more potent that expected) send its fallout in the opposite direction, and for a much further distance than predicted because it pushed the fallout into a high level stream.
The idea that you can predict the effect of a “nuclear attack” with no further qualification is hopeless. Also, the nature of nuclear attack has changed over time. Earlier in the cold war weapons were big and needed to be due to poor guidance on delivery. Megaton weapons were needed to ensure a kill of a target. Now delivery is pinpoint, and the need for seriously powerful weapons much reduced. This assumes a targeted nuke on a strategic target - whihc is rather different to a multi-megaton nuke intended to destroy an entire city in one go as part of a retaliatory strike.
OK, here’s some results from image searches:
Map 0- An example of how many Fallout 4 references I keep hitting
Map 1- This map seems to presume a very large number of ground bursts, apparently in a deliberate attempt to maximize fallout saturation. http://tomnichols.net/blog/wp-content/uploads/2012/08/Fallout_Map_3-23-1963-Saturday-Evening-Post.jpg
Map 2- Another saturation attack? Areas blanketed that were not blanketed on Map 1, and vice-versa. http://blog.nuclearsecrecy.com/wp-content/uploads/2014/02/1986-OakRidgeFallout-ORNL-6252-600x416.jpg
Map 3- Not sure what this map is about; fallout if only nuclear weapons sites targeted? http://www.futurerevealed.com/maps/images2/fallout2.gif
Map 3a- another version of above, this with fallout source targets labeled. http://modernsurvivalblog.com/wp-content/uploads/2011/12/fema-nuclear-target-map.jpg
Map 4- A targets-only map, with no accounting of fallout. http://www.truthsurvival.com/wp-content/uploads/2016/04/USA-targets-nuclear-attacksrr.jpg
Map 5- A fallout-only map, with no accounting of local targets. https://upload.wikimedia.org/wikipedia/commons/a/ab/Fallout_map_USA_(FEMA).jpg
Map 6- A pretty widespread fallout map. http://modernsurvivalblog.com/wp-content/uploads/2011/12/nuclear-fallout-1-week-later.jpg
WTF?
A better version of map 2 from my previous post:
Map 2a. http://i190.photobucket.com/albums/z235/newbie_bucket/Fig004-0120Simplified20Fallout20Pat.jpg
Maps 1 and 2 are labeled as 3000 and 5000 megatons of ground bursts respectively- that seems kinda high, especially post-Soviet Union.
“Need answer fast!”
Pretty clearly each map is making a different set of guesses about the target set. Some guesses may be well-founded, others are almost certainly just WAGs or pretty pictures.
The only people who know for sure what’s targeted and how hard each will be hit are the enemy. Even then, if they’re anything like us, they’ve got a lot of different plans with different emphases for different scenarios. So until they pull the trigger on either Plan A or Plan B even they don’t know whether to expect fallout pattern A or B.
Some of these have the plumes generally convex to the south, others have the plumes convex to the north. Which shows us they’re making different assumptions about the pattern of surface weather highs and lows and the location of the jet stream(s).
Anyone who looks at a national weather map or satellite photo can see that the pattern of clouds differs vastly from day to day. So would the pattern of fallout from an attack on the same target set on different days when different weather patterns were in effect.
Overall I like FEMA’s map (your #5) for the most useful *conceptual *information.
Look at the plumes hanging off the Los Angeles and Miami areas. Notice how large the yellow area is versus the dark red area. That’s your clue that although fallout >0 will be widespread, very high levels will be much smaller, more concentrated, and closer to the detonation.
Notice also the plume is far longer than it is wide. Said another way, a plume from someplace upwind could easily go past your area without affecting you at all. All else equal, better to be west of a detonation than east.
That map assumes an attack largely focused on the ICBM fields. If that comes to pass, most of the northeast quadrant of the country will be at least lightly dusted. Trying to extract more detail than that is silly.
After that there’s not much more anyone can say about fallout patterns. Exactly where, when how high, how much yield for each detonation plus exactly what is the weather at that time are the minimum inputs to say more.
Based on the FEMA map #5, Oregon’s state motto should be: “The Fallout Free State”
Who is Nuking Mexico?
More importantly Why?
Umm, you do know about downwinders don’t you?
Donald Trump. He might if the dick waving contest got out of hand. Honestly this scenario is unlikely, but apparently there are no actual checks preventing Trump from picking up a phone and ordering a nuclear strike basically anywhere and at any time.
