Nuclear stockpiles, big explosions, the earth, and the Moon.

Factual Questions
1

Based on this Natural Resources Defense Council website, there were >20,000 - give or take a few hundred - nuclear weapons (warheads, bombs, whathaveyou) extant worldwide as of 2002. That’s a heck of a lot of doomsday potential there.

What would happen to the earth if every last bit of this nuclear arsenal was ‘exploded’ simultaneously -
[ol]
[li] in the Pacific ocean?[/li][li] over Siberia?[/li][li] in Antarctica?[/li][li] on the moon?[/li][/ol]
Any clues?

(Lest anyone suspect this is a homework thing, rest assured my homework days are long past.)

2

Well, explode a bunch of nukes (but not all of them) over the Ross Ice Shelf in Antarctica and you’ve got the plot of Icefire.

3

IANAPhysicist, or in possession of any other relevant qualifications, but it seems to me that the damage would be greater if the nukes weren’t all piled together in a single heap; I don’t think their yields can simply be added together, because of limiting factors such as the size/force of the shock wave that can be generated given a specific volume of atmosphere.

4

As far as the Earth was concerned, not much of an effect. Forget those cheesy science-fiction movies where we knock the Earth out of its orbit or split open the crust. Setting them off over Siberia could cause major forest fires. The main problem would be fallout plumes. The amount of damage would be dependent on weather patterns and how the weapons were fused.

Setting them off on the Moon would be anticlimactic. It would cause some minor surface damage.

5

Or is it another exercise in MM?
Why not explode them all in the center of the core of the earth and have the next "Big Bang.?

6

Let’s say each is roughly 1 MT worth of explosive. That gives us 20,000 MT which is roughly equivalent to a 1 km asteroid hitting the earth. That’s a 9 on the Torino scale meaning it would be equivalent to a collision capable of causing regional devastation.

Move the yield up to 10 MT and you’ve got a 10, which roughly means global devastation.

Link for a description of the Torino scale

7

The recent tsunami was at least that powerful.

http://www.cdnn.info/industry/i041228c/i041228c.html

Cox News

Hiroshima was 20 kilotons, so that’s the equivalent, minimally, of 20,000,000 kilotons, or 20,000 megatons.

It’s true that regional devastation resulted, but the effects were multiplied because of the way a slipping fault creates a shock wave. An explosion, being more diffuse, might not create a tsunami at all. And it might have only half the power of the earthquake.

Nothing we can do has the power or destructive potential of what the earth naturally does on a regular basis.

8

The problem is that the asteroid’s energy is in the form of kinetic energy and a nuclear weapon’s energy is in the form of thermal energy. The effects are going to be very different.

The U.S. arsenal is approximately 1,850 megatons and the Russian arsenal is approximately 2,800 megatons (link).

9

But not all the energy was channeled into the water; it also went into moving billions of tonnes of rock. I mean http://neic.usgs.gov/neis/bulletin/neic_slav_ts.html ]look at the scope

10

How long will it be until the tritium triggers on these nuclear bombs no longer work? Do nuclear bombs go stale?

11

Fission bombs don’t go stale , but tritium has a about a 12 year half life making fusion bombs a harder proposition.

12

Tritium is commonly used to boost the yield of fission weapons and the fission primaries in thermonuclear weapons.

13

Why do you think Los Alamos, Oak Ridge, and Lawrence Livermore are still in business? They’re not designing new bombs after all.

What they are doing, among other things, is doing research and testing to determine the effects of storage and time on nuclear weapons, so that they’ll go bang if they’re ever actually used. They also periodically refurbish ones whose components may have deteriorated (i.e. the tritium decayed).

Currently, the tritium used to recharge weapons is from dismantled ones, but there are plans to use some of the Tennessee Valley Authority’s reactors to breed tritium in the future when the dismantling is done.

The US hasn’t actually tested a nuclear weapon since 1993, and hasn’t manufactured any since 1990.
http://nuclearweaponarchive.org/Library/Catalog
http://www.stopthebombs.org/nuke/map.html#Pantex
http://www.nnsa.doe.gov/docs/nl_2004Aug_NNSA_News.pdf

14

Ok fair enough. Boosted fission weapons use small amounts of tritium drive the fission reaction into 100% of the fissionable material.

I’d guess (given the bigger bang for the buck military crowd) that means every fission weapon is likely a boosted one.

15

Even if we assume that each of those warheads is a 20-megatonner, we have about 400,000 megatons of nuclear destruction. The asteroid impact that marked the end of the Cretaceous period had the equivalent energy of about 100 million megatons. In terms of pure energy involved, then, the Earth has survived worse.

16

A couple of nitpicks, and then an answer:

First of all, tritium isn’t used as a “trigger”; the trigger is a small fission device (the “Primary” consisting of Pu-239 or U-235 (enriched)), which sets off a larger “boosted” (“Secondary”) fission device (the boost comes from additional neutron production), which then creates the pressure and thermal pulse to ignite a fusion reaction in the weapon core.

Second, nobody puts tritium in the core as the fuel for fusion. As has been noted, tritium has a short half-life (12.3 years). Instead, they use deuterium, or rather, lithium deutride (more chemically stable than pure hydrogen), which is radioactively stable. The “Secondary” boost reaction causes D-D fusion which generates (though a complicated process) tritium, which then leads to the more energetic D-T reaction. (The higher order reactions-D-He, He-He, and beyond–aren’t of issue because the detonation doesn’t last long enough for these to occur in significant quantities.)

As for how long the warheads are good, I don’t really know for sure. The weapon material itself is good for quite a while–although it will undergo some reaction due to the proximity of radioactive material, the neutron flux is still fairly low, and lower yet in modern multistage weapons with lower subcritical mass requirements. Reprocessing is done more to obtain material for new weapons than to refurbish old ones. I expect that the neutron flux probably creates some degree of hydrogen embrittlement in materials within the “physics package”, but I imagine that materials and construction have been selected to minimize this.

As for the OP, I suspect the result would be…surprisingly little, especially if detonated over an ocean. The nuclear winter hypothesis has been largely discredited, and as others have pointed out, a large seismic or medium sized meteological event has more energy than we could hope to create on our own. For the vast and horrible power of our destructiveness, we are but gnats compared to Mother Nature. A reasonable sized asteroid would do more damage than we could do on our best day.

But hey, we’re working on it. One of these days, we’ll have one of them Doomsday Machines of our own. “Gentlemen, we have a mineshaft gap!” :dubious:

Stranger

17

:confused: We could easily kill off ourselves, along with a good chunk of the other species of plants and animals on Earth with nuclear weapons. We wouldn’t do a thing to the giant rock we’re sitting on, it would keep on spinning on its merry way. In all likelyhood in the long run life wouldn’t even really notice. There have been mass extinctions before from far worse catistrophic events. If we really did set off nukes evenly across the globe I’m pretty sure there would be a nuclear winter, just that in a few hundred thousand or in a million years things would be pretty much back to normal (minus those pesky humans and some other unlucky species).

Yes, a massive nuclear exchange would be less catistrophic than what has happened naturally to the Earth before, but I’m absolutely sure there would be a nuclear winter or other such mess that would clean itself up after a very very long time (short time, geologically speaking) and life would move on.

18

Could you expand on the bit about explosions being more diffused? Don’t explosions have a point source too?

Regarding the OP, why I provided different locations for the detonation was that I wanted to see if the geographical features of the site would affect the results of the explosion. So, a Pacific ocean boom would likely lead to a tsunami, though less powerful than the natural one the world just saw.

How about an explosion in some uninhabited expanse in Siberia? Not much effect? Nuclear fallout spreads over Eurasia, leaving the rest of the world unaffected except in terms of political/economic shockwaves?

Or under a central ice field in the Antarctic. Large scale melting of the ice, leading to extensive flooding of coastal regions? Something else too?

The moon! Being much smaller, would a subterranian 400,000 Megaton explosion manage to rip out a significant chunk of land mass and send it flying? Wouldn’t tides on earth be affected if this happened?

(This OP inspired by the Jules Verne’s lovely little book - From the Earth to the Moon.)

19

Nuclear weapons are overrated. The reason that we fear them is that our society is so fragile and interdependent. It would not take a large number of properly targeted nuclear weapons to cause catastrophic damage to a modern country, even though the physical area affected would be small. The Earth’s surface is approximately 500 million square kilometers. That is really big. The detonation of every nuclear weapon in the world would cause catastrophic damage to about 0.5% of the Earth’s surface. Fallout would affect a larger area, but that is a short-lived phenomena.

20

You mean it wouldn’t send the Moon flying out of the solar system and into a space warp? :wink: