One Hiroshima for Every 6K People: a Map of the Effects of a 20,000 Megaton Attack on the U.S., 1963

JF Ptak Science Books    Post 1947  Part of a long series on the History of Atomic and Nuclear Weapons

 

I found this map via Alex Wellerstein--a very odd, very visual map of radiological effects of a massive nuclear weapons exchange, which basically leaves little in the way of hope for survivability.  It was published in Brookhaven National Laboratory's  Ecological Effects of Nuclear War (edited by G. M. Woodwell) as part of symposium sponsored in part by the Ecological Society of America and the American Institute of Biological Sciences in 1963. Wellerstein (an historian at the Center for the History of Physics at the American Institute of Physics)  correctly points out the problems with the model--among which are the 100% ground detonation and 100% achievability in yield--but there was something else that bothered me.  Well, two things:  first. the swath of death obliterated state lines, so you could sort of tell who was affected (although it seems as though my own mountain city of Asheville, NC is in a very slim thread of beige spiking into the death blotch), not that these distinctions would matter very much in the light of nuclear holocaust.

The second part didn't occur to me until later.  The missing state lines wouldn't matter because there would be basically nothing left, or a something that approached nothing.  As Sven Lindqvist points out in his book A History of Bombing (The New Press, 2001),  a study conducted at the Max Planck Institute in 1982 showed that an exchange of 5,000 megatons was enough to throw hundreds of millions of tons of soot from burning forests into the atmosphere and create a cloud barrier that would last for six months and cause the temperature on Earth to drop 100 degrees. At the end of that time, after the sun poked its way through again, the damage to the ozone would be such that virtually anything that survived would be killed by UV radiation.  Plus all of that nuclear exchange radiation.  at the time--in 1982--the worldwide stockpile of nuclear weapons was acknowledged to be about 13,000 megatons. 

It is estimated that 13,000 megatons had the damage capacity of 1,000,000 Hiroshimas, due not to increase weight but also to more efficient weight usage. That's one Hiroshima for every 6,000 people.

Comments

[Wellerstein]

Hi John — Wonderful write up. Just one pedantic point: the issue is not so much that 100% of the yields would be achievable, but that 100% of the yields would be fission. Most thermonuclear weapons are (by definition) not 100% fission in their yields. They can vary quite a bit, but the general rule of thumb is 50% fission, 50% fusion in modern fission-fusion-fission warheads. So the amount of fallout (which is primarily caused by fissioning, not fusion) would be somewhat reduced from what is shown here. Similarly the choice of ground bursts would also make more fallout than would occur if it were a (more probable) mixture of ground and air bursts. So this map is definitely a worst-case scenario, to the point of not reflecting the actual weapons in play at the time (or since).

None of which is to say that the results for the country or the planet would probably have been much less dire than you conclude, especially if you consider that this sort of damage would likely have had its counterpart over in Russia as well.

Glad to see someone else who has read and enjoyed Lindqvist's book! It is an unusual and surprisingly unheralded little manuscript, one of my favorites.