North Korea has completed its third nuclear test

February 12, 2013 1:20 AM

Around midnight local time (UTC +9) on 12 February the Democratic People's Republic of Korea detonated a 6-10 kiloton nuclear device at the Punggye-ri nuclear test facility.

Reactions have been nearly immediate. South Korea has put its military on high alert. President Obama called the test, "a threat to U.S. national security." China expressed its "firm opposition" to the test, and China may be becoming less tolerant with its neighbor.

Al Jazeera reports that the weapon was "'miniaturised'" [which] will raise alarm around the globe, with its suggestion that Pyongyang has mastered the technically complex process of producing a warhead small enough to fit on a long-range missile."

posted by digitalprimate (80 comments total)

Quick! Somebody give them all the oil and food they want!
posted by TrialByMedia at 1:29 AM on February 12 [2 favorites]

...and their nukes are still are far less important than the fact that DPRK have the ability to kill almost all of Seoul with conventional/chemical shell artillery at 5 minutes notice.
posted by jaduncan at 1:30 AM on February 12 [20 favorites]

Al Jazeera reports that *North Korea says* it's miniaturised.

Hopefully a useful distinction.
posted by panaceanot at 1:39 AM on February 12 [5 favorites]

It's important not to overreact, draw a clear line in the sand, and be prepared to back up tough talk with action:

January 20, 2004. George W. Bush's Fourth State of the Union Address

"Along with nations in the region, we are insisting that North Korea eliminate its nuclear program. America and the international community are demanding that Iran meet its commitments and not develop nuclear weapons. America is committed to keeping the world's most dangerous weapons out of the hands of the world's most dangerous regimes."

NY Times, Oct 10, 2006: For U.S., a Strategic Jolt After North Korea’s Test

"North Korea is more than just another nation joining the nuclear club. It has never developed a weapons system it did not ultimately sell on the world market, and it has periodically threatened to sell its nuclear technology. So the end of ambiguity about its nuclear capacity foreshadows a very different era, in which the concern may not be where a nation’s warheads are aimed, but in whose hands its weapons and skill end up."

... and their nukes are still are far less important than the fact that

Charter member of the Axis of Evil, the world's most dangerous weapon in the hands of the world's most dangerous dictator, we can't wait until the smoking gun is a mushroom cloud over Manhattan... need I say more?

Quick! Somebody give them all the oil and food they want!

It's been done. Most recently by the George W. Obama administration

March 1, 2012:

"(CNN) -- In return for food aid from the United States, North Korea has agreed to stop nuclear activity at its main facility in Yongbyon, both countries said Wednesday.
North Korea has also agreed to a moratorium on long-range missile launches.

"Today's announcement represents a modest first step in the right direction," U.S. Secretary of State Hillary Clinton said. "We, of course, will be watching closely and judging North Korea's new leaders by their actions."

Well, at least she won't have to answer any more questions about Benghazi.

Hurry Mr. Obama, hit them again with more sanctions and make sure to strongly condemn them. You wouldn't want anything to distract you from preventing Iran from developing a nuclear weapon.
posted by three blind mice at 1:48 AM on February 12 [3 favorites]

Just for reference -- that's smaller than Little Boy. A 6-10kt nuke wouldn't even reach across the potomac if it targetted the Pentagon, though fallout is another story.
posted by empath at 1:48 AM on February 12 [1 favorite]

Well look at it this way: their biggest enemy, the great foreign devil, have the world's largest stockpile of nuclear weapons, and have proved a willingness to use them in times of war in the past (in that part of the world, no less). How does it not make sense for them to get their own nuke, within that frame of reference, that worldview?
posted by Dysk at 1:49 AM on February 12 [6 favorites]

Well look at it this way: their biggest enemy, the great foreign devil, have the world's largest stockpile of nuclear weapons, and have proved a willingness to use them in times of war in the past (in that part of the world, no less). How does it not make sense for them to get their own nuke, within that frame of reference, that worldview?

Well, yeah, but the main point of it is to piss off Japan and keep DPRK in the news.

Seoul has 10 million people in the city limits alone; nobody is gambling that much with that many people, especially given the sheer amount of damage that large scale destruction of a place with a $700+bn GDP would cause to both the general world economy and the financial/insurance sectors in particular. Counterparty risk is impressive when you kill off most of Samsung and the other chaebols.

Oh, and any "winner" of the war then also has to govern North Korea's population. Hello refugee camps and East German integration cubed.
posted by jaduncan at 2:00 AM on February 12

Oh, and any "winner" of the war then also has to govern North Korea's population.

Assuming there will be any of it left after both sides go large on each other.
posted by three blind mice at 2:15 AM on February 12

...and their nukes are still are far less important than the fact that DPRK have the ability to kill almost all of Seoul

I disagree. Those nukes are likely for sale.
posted by Tell Me No Lies at 2:20 AM on February 12

Just for reference -- that's smaller than Little Boy.

My understanding (and I claim no expertise) is that small nukes are in fact harder to make than medium sized ones because working out how to make them go boom is much harder.
posted by wilful at 2:27 AM on February 12

Anybody who's paid attention over the last decade or so knows that having nuclear weapons is a magic "don't get invaded" shield- North Korea would be foolish not to pursue nukes. That said, we could decapitate the DPRK right now, just the entire government vanishes into the ether even, and we'd still be fucked because the ultimate poison pill is that North Korea represents one of the most horrifying ongoing disasters in the world. 24.5 million starving people who've been raised since birth to believe that the world outside of the DPRK is a hellhole that wants to invade their country and kill them? Gee, that's a population I'd sure like to be involved with coordinating aid and rescue for.
posted by Pope Guilty at 2:29 AM on February 12 [16 favorites]

For RoK use, they have them. There's an awful lot of tunnels back and forth.
posted by jaduncan at 2:35 AM on February 12

I am reminded of this excellent comment about North Korea's shenanigans. Excerpt:

They are playing in a region where the neighbours (the DPRK propaganda site mentions the 'six country talks') are the world's #2 and #3 superpowers (China/Russia, you argue the order), an economic superpower (Japan), a decent regional power in the South that has significant financial and military muscle, and the US of course, who is interested in everything everywhere. That's the definition of a high-stakes table, and North Korea has been playing poker against these guys for 65 years, from a deck of 2s, 3s, 4s and 5s. You don't do that by being dumb or insane or crazy or ideologues, you do that by being clever as hell and bluffing for all you're worth. And every once in a while, pulling some crazy shit, like shelling a random island, or showing off your uranium centrifuges. So they can't tell if you're bluffing or crazy. [....]

It's terrifying and stupid, but the DPRK need one of these shenanigans every once in a while to convince the rest of the world that they're still unpredictable, and that they just might do it. I don't think so, but -- and this is the beauty -- despite all of my blather here assuring you all otherwise, I just can't be sure.

posted by lalex at 2:42 AM on February 12 [33 favorites]

Gee, that's a population I'd sure like to be involved with coordinating aid and rescue for.

Which is why it's much better to just maintain the DPRK and if the regime could follow the PRC you'd have an ideal little global economy on the korean peninsula: high valued-added design and manufacture in the South and a industrial slave economy in the North: synergy!
posted by ennui.bz at 2:46 AM on February 12 [3 favorites]

small nukes are in fact harder to make than medium sized ones

I'm no expert either, but I wonder if the DPRK had planned for a much larger yield, and it failed partially. Probably hard to say at this point, but no doubt some scientific analysis of the detonation will be posted before too long.
posted by Legs11 at 2:48 AM on February 12 [1 favorite]

I'm no expert either, but I wonder if the DPRK had planned for a much larger yield, and it failed partially.

I wouldn't be too surprised if they just don't have the spare fissile material to build too big.
posted by jaduncan at 2:53 AM on February 12 [1 favorite]

"North Korea has been playing poker against these guys for 65 years"

Of course their ace, conspicuously noticeable in the folds of their sleeve, is that if they lose their shirt to the game, they're not simply going to flip the table in disgust, they're going to shoot the guy beside them point blank.
posted by panaceanot at 2:56 AM on February 12 [2 favorites]

Go to this google maps mash-up, choose Seoul from the target list, enter 7 kt for the yield. Look a bit to your right, where the purple and olive green lines cross, that's my neighborhood! .... I'm safe right guys? right?
posted by nile_red at 3:45 AM on February 12 [2 favorites]

Go to this google maps mash-up, choose Seoul from the target list, enter 7 kt for the yield. Look a bit to your right, where the purple and olive green lines cross, that's my neighborhood! .... I'm safe right guys? right?

Well, if the nuke don't get you, the conventional bombs certainly will.
posted by ymgve at 3:57 AM on February 12

Well, if the nuke don't get you, the conventional bombs and massive quantaties of chemical weapons aimed at all the escape routes certainly will.
posted by jaduncan at 4:02 AM on February 12

the ability to kill almost all of Seoul

Hyperbole.

Have you ever been to Seoul? It's enormous. 10 million people in 233 square miles of concrete buildings, both surface and subsurface. It's also thirty miles from the border with North Korea. It would take years of coordinated, sustained, simultaneous, large-caliber, observer-directed long range artillery fire to even make a dent. And that's with air superiority and without any competent counter-battery measures. An unrealistic scenario.

At that distance, conventional artillery is a terror weapon both literally and figuratively. It's ineffective yet scares the crap out of anyone who is susceptible to propaganda, the History Channel or both.
posted by jsavimbi at 4:26 AM on February 12 [1 favorite]

Odd timing. I had figured they'd do something like this on Lunar New Year, not a day or two later.
posted by ardgedee at 4:30 AM on February 12

I'm in Seoul right now. I'm not Korean, but after 5 years, I've learned not to be freaked about things unless the locals are. In short, it's being reported, but people aren't visibly concerned. Maybe they will in time, but today (the earthquake being reported this morning Korean time) there didn't seem much cause for concern.

The USA has little reason to fear. So long as South Korea and Seoul keep thinking they have more to lose than gain, the North has the upper hand.

That said, the 'sh!t hits the fan' bag needs to be updated.
posted by chrisinseoul at 4:31 AM on February 12 [1 favorite]

I'd expect that both South Korea and the US have plans for annihilating the DPRK's Seoul-targeting artillery within a few minutes of it beginning to fire.
posted by Pope Guilty at 4:35 AM on February 12

"Go to this google maps mash-up, choose Seoul from the target list, enter 7 kt for the yield. Look a bit to your right, where the purple and olive green lines cross, that's my neighborhood! .... I'm safe right guys? right?"
posted by nile_red

No because then America will join in and the only way to be safe will be to be on another continent, as we all know how inaccurate they are with this stuff.

I love how America's leaders bang on about North Korea, as though it is some massive military superpower that actual poses a substantial threat to mainland USA. Its like Hulk vs (Where's) Wally.
posted by marienbad at 4:48 AM on February 12

Since it came up... here's a crash course in nuclear weapons. All numbers are very approximate, but in the ball park.

Simple uranium-based fission bomb: yield 10-50 kT (enough to ruin your day), size a few meters across (too big to fig under your coat). Separating the isotopes U235 from U238 is a pretty large-scale industrial effort because the two behave the same way in all chemical reactions. The only difference is the ~1% difference in mass. But U235 you use to make bombs, U238 is a waste product that they make into bullets because it's very dense (these are the famous depleted uranium bullets, called depleted because they're depleted of U235). Separating U235 is the hard part. Once done that, making a bomb is dead easy. That's why everyone is always worried about who's building centrifuges.

Plutonium based fission bomb: yield 10-50 kT, size a few meters across. Here separating the material is easy because plutonium is chemically different from the stuff you're trying to separate it from. No centrifuges are necessary, just some chemicals and beakers (well, not really, but it's not too hard). The hard part is actually designing the bomb. Basically the problem with plutonium is that it's on a little too much of a hair trigger: when you try to detonate the bomb, the plutonium gets things going too quickly, before you've fully assembled the critical mass of material. When that happens, the bomb blows itself up before it's really supposed to go off, and you end up with a "fizzle" instead of an explosion. So you have to assemble the critical mass of plutonium very quickly, leading to the implosion-based "fat man" bomb design. The task here has been likened to "using high explosives to crush a beer can without spilling any beer."

Hydrogen-based fusion bomb: yield 1-10 MT, size somewhat larger (not much) than the above. Here you're using a fission bomb as the trigger for a much larger bomb. So you don't build these until you've fully mastered making one of the two options above. The upper limit of 10 MT is not a technological limit: there's no problem making a 100 MT hydrogen bomb. The problem is that the time for the fireball to reach maximum size becomes longer than the time required for the fireball to buoyantly rise off the surface of the earth (forming the characteristic mushroom cloud). Therefore the fireball would continue to grow, but it wouldn't knock down any more buildings, so there's no practical purpose to building bombs bigger than 10 MT.

"suitcase nuke": yield 0-10 kT, size: suitcase. As nuclear weapons go, these are very small. However, the worry is that you can pretty much literally it them into a suitcase, the trunk of a car, etc. Car bombs are bad enough. Now imagine a car bomb that levels everything for 500 meters in every direction. The good news is that designing these is extremely hard. You have all the same problems as with a standard size "fat man" implosion style bomb design, all made much harder by the fact that you're trying to miniaturize it. So the compression ration has to be yet higher, the amount of "beer" that you spill has to be yet smaller, etc.

To respond directly to the comment above that it's hard to build small bombs: it's hard to build bombs that are intended to be small. Another way to get a small explosion is to build one that's supposed to be big (well, medium sized) with a yield of 10 or 20 kT, and then have it fail in some way. That could easily result in an explosion with a yield of, say 1 kT.

Finally, it's a bit misleading to say "the bomb was smaller than little boy," implying that it's not all that great. It's true that that size of a bomb wouldn't turn all of Manhattan into a glassy crater (like a 10 MT bomb would), but if a 10 kT bomb goes off in the center of any major city in the world, we're facing an unbelievable level of physical and psychological trauma. Just ask the residents of Japan.

A brief disclaimer lest anyone get the wrong idea. (I am a physicist, I am not your physicist, this is not physics advice...?) All of the above information is easily available from public sources to anyone interested. I'm not in any way involved with weapons design, etc, and those who are actually interested in these things know far more than I do.
posted by ngc4486 at 4:48 AM on February 12 [54 favorites]

Well look at it this way: their biggest enemy, the great foreign devil, have the world's largest stockpile of nuclear weapons, and have proved a willingness to use them in times of war in the past (in that part of the world, no less). How does it not make sense for them to get their own nuke, within that frame of reference, that worldview?

Wait, are you suggesting that the United States is actually their biggest enemy? And not just the bogeyman the DPRK has used since the 50s to keep their population distracted from poverty, famine, etc.? The biggest threats to the United States here are either 1) the DPRK selling this weapon to Iran, which is really just a threat to Israel, or 2) the DPRK attacking an ally, which would suck for us but would suck a lot more for our ally. As for DPRK? The United States certainly doesn't like that regime, but come on. They are not our most pressing issue. This is a local threat, and as such, the biggest players (in your parlance, perhaps, their "greatest enemies") are South Korea, Japan, China, and Russia.

The sad thing is that time and time again, the DPRK has chosen to funnel all of its money, research, time, and attention into developing weapons instead of agriculture, housing, education, and economic development. At least Iran, Syria, and other countries with covert weapons programs choose to combine their research with an actual society.
posted by (Arsenio) Hall and (Warren) Oates at 4:55 AM on February 12 [2 favorites]

Would there be a noticeable difference in the seismic activity profile of a 6kt nuclear detonation contra 6000 tons of conventional explosive?

I'm not suggesting the North Koreans gathered up 6000 tons of TNT rather than building a small nuke, I'm just curious.
posted by knapah at 4:56 AM on February 12

And, FWIW, there are new reports out this morning that the "quake" lasted roughly a minute and size estimates have been revised up to ~15kT.
posted by (Arsenio) Hall and (Warren) Oates at 4:57 AM on February 12

Plutonium based fission bomb: yield 10-50 kT, size a few meters across. [...] The hard part is actually designing the bomb.

Well, that and getting the plutonium: you need access to a nuclear reactor (which you need to fuel with something else) plus some rather nasty chemistry - possibly simpler than producing high-enrichment uranium, but definitely not trivial. Ensuring that plutonium produced in power reactors does not end up in the hands of people like the DPRK is one of the major design requirements for nuclear power.
posted by Dr Dracator at 4:57 AM on February 12

What Do We Know About The Apparent Nuclear Test In North Korea?
posted by the man of twists and turns at 5:07 AM on February 12

I'd expect that both South Korea and the US have plans for annihilating the DPRK's Seoul-targeting artillery within a few minutes of it beginning to fire.

The Paladin PIM program - radar-directed, networked, autoloading, self-propelled anti-artillery howitzers, which could drop three bunker-buster shells on a distant and dug-in artillery position in under a minute - was scaled back in the '90s. The money was needed for the Osprey and F35 and B2 bombers and other useless cold war shit.

Dropping a nuke wouldn't even help, as a lot of those artillery positions are hardened, and they can roll in their mobile artillery and AA reserves.

So, no... there is no magic bullet against DPRK artillery and long range missiles. Rhinemetal HEL laser emplacements may fill that role, but we're around 5-10 years from the deployment of a useful system.
posted by Slap*Happy at 5:14 AM on February 12

Just for reference -- that's smaller than Little Boy. A 6-10kt nuke wouldn't even reach across the potomac if it targetted the Pentagon, though fallout is another story.

Building "Small" nukes like that is actually more technically complicated then building huge ones, from what I understand - especially they really did get it miniaturized. Low yield doesn't necessarily mean low tech.

On the one hand, you would think that North Korea, being who they are, would want to make the biggest explosion possible. On the other hand, if they set of a "small" bomb it's much more likely they have one that doesn't weigh much, and that signals that they might have the ability to launch it to Seoul or even Japan just using one of their smaller rockets that would be hard to detect. I think for their neighbors, a small nuke would be more frightening then a huge one.

I'd expect that both South Korea and the US have plans for annihilating the DPRK's Seoul-targeting artillery within a few minutes of it beginning to fire.

Yeah, that's the thing. The US/SK have had 60 years to plan for this potential shelling, and a huge incentive to invest in technologies to stop it assuming they can detect where the shells are located it should be easy to bomb the launch sites quickly and take them out. I don't really know if conventional shelling could really do that much damage before the launchers are destroyed. Chemical weapons could theoretically kill a shitload of people though.

Wait, are you suggesting that the United States is actually their biggest enemy? And not just the bogeyman the DPRK has used since the 50s to keep their population distracted from poverty, famine, etc.? The biggest threats to the United States here are either 1) the DPRK selling this weapon to Iran, which is really just a threat to Israel, or 2) the DPRK attacking an ally, which would suck for us but would suck a lot more for our ally. As for DPRK?

The problem is, who exactly are North Korea's Enemies at this point? The only other candidates for "biggest enemy" are South Korea and Japan, South Korea doesn't want a war with NK, they've been making friendly overtures lately (Their newest president has said they want to try to have a better relationship with NK - we'll see how that goes)

Then there's Japan - certainly there is a lot of hatred of Japan in NK due to world war II, something the North Korean government puts a lot of effort into reminding people about. But Japan doesn't have an offensive military at all, they have no nuclear weapons and they certainly don't have any interest whatsoever in taking over North Korea, so it's hard to argue that Japan is their biggest enemy.

Finally, it's obvious that the US doesn't give a crap about North Korea one way or another. But we're still obviously involved in containing them and we still have a large military presence in NK. The biggest difference, though between the US and Japan/SK is that we actually have nuclear weapons and the ability to use them, and for now they don't really have much of a way to strike back at us the way they do South Korea. So really the US poses the greatest threat to them.

Now obviously the threat isn't very high. From an outsider perspective it doesn't really seem like North Korea is very threatened by anyone at all. The problem is they've been stewing in their own paranoia for decades, and because they're so scared they act crazy, which in turn freaks out their "enemies" who then try to get them to calm down which then fuels their persecution complex.

The other aspect, though, is that this probably has a lot to do with internal politics as well. To the outside world it's a demonstration that they're serious and technologically skilled, and internally this may be a way to show to other members of the elite that the government is actually at least semi-competent and capable of building nukes and orbital rockets and the like. Good for morale.
posted by delmoi at 5:19 AM on February 12 [1 favorite]

I sure hope the next Call of Duty has something to say about this. Call of Duty is where I get all my international news.
posted by turgid dahlia 2 at 5:21 AM on February 12 [2 favorites]

Having spent a small amount of time around the area - I visited Panmunjom, stared into the enemy's eyes and gave him a smile - hungry? I can tell you this - both ROK and DPRK have got some some elements of batshit crazy hardliners.

However, the answer imo isn't assassination of leadership or more sanctions - its returning to Panmunjom and talking it out, bringing PRC with us and asking the hard questions:

"Further displays of wonton aggressiveness will only alienate your country further, while simultaneously decreasing the respect you receive from your neighbors - this is the price of your insecurity, did you realize this?"

"Who's in charge here?"

"Did daddy not love you enough?"
posted by vonstadler at 5:23 AM on February 12

I'd expect that both South Korea and the US have plans for annihilating the DPRK's Seoul-targeting artillery within a few minutes of it beginning to fire.

North Korea can't defend its airspace for long without Chinese support. It would take a little time (maybe a few days, probably less) to reduce their air defenses enough for strike aircraft to operate in relative safety, but after that their conventional artillery would be pretty vulnerable. And in a dire enough situation, we might not wait to attrit their air defenses. Yes, we scaled back the computer-controlled counterbattery system, but that shouldn't threaten to change the likely outcome of such a scenario. The response just wouldn't be as immediate. The only question mark comes from the drawdown of forces based in the RoK and Japan. However, Obama's recent remarks about the Pacific needing our renewed attention and focus might suggest a reversal of some of that. And sorties can be flown from halfway around the world these days, until forces can be moved back into place.
posted by snuffleupagus at 5:26 AM on February 12

Would there be a noticeable difference in the seismic activity profile of a 6kt nuclear detonation contra 6000 tons of conventional explosive?

No difference.

Nuclear weapons test monitoring also involves satellites looking for gamma rays, although that doesn't help for underground tests.
posted by ngc4486 at 5:26 AM on February 12

The greatest enemy of North Korea is the Kim family.
posted by Pope Guilty at 5:29 AM on February 12 [5 favorites]

Hydrogen-based fusion bomb: yield 1-10 MT

In practice most thermonuclear warheads are in the 100-500KT range; more than that seems to be tactically "wasteful" with modern targeting accuracy. Also, modern MIRVs are man-sized or smaller.

What I hadn't known until curious recently is that modern designs aren't just fission-fusion but fission-fusion-fission where some or most of the fusion reaction's purpose is to direct a huge spray of neutrons at the U238 casing -- so much that it starts fissioning. The third-stage fission can be a major component of the warhead's final destructive power.

Makes the whole thing that much creepier -- we're going to set of a Hiroshima-style citybuster, but no, that's not it. We're really only going to use the citybuster to set off another fusion explosion that's even more powerful. And because we really want to make sure all your men, women, and children burn, we're not going to stop there -- we're going to harness some of that huge secondary explosion to generate another, bigger, fission explosion.
posted by ROU_Xenophobe at 5:30 AM on February 12 [2 favorites]

Just how miniature is miniature here? Because given the talk of artillery, let's not forget that that's another way to deliver a nuke.
posted by snuffleupagus at 5:35 AM on February 12 [1 favorite]

Anybody who's paid attention over the last decade or so knows that having nuclear weapons is a magic "don't get invaded" shield- North Korea would be foolish not to pursue nukes.

This was part and parcel of the Iraq invasion. The US basically told the world that our foreign policy was, "We will have our revenge on those who masterminded 9/11 and those that give them succor.... OOOOOOH! SHINY!" and that, while the US said it wouldn't tolerate certain rogue states developing weapons of mass destruction, it proved beyond any doubt that not having weapons of mass destruction was absolutely no guarantee of anything.
posted by Kid Charlemagne at 5:40 AM on February 12

A 6-10kt nuke wouldn't even reach across the potomac if it targetted the Pentagon, though fallout is another story.

Well, that's true, but the area is basically the Pentagon and not much else. Drop a 6kt nuke at State and Madison in Chicago, and you'll have destroyed the entire Chicago Loop -- and Most of River North, Printer's Row, West Loop, Grant Park, and Millennium Park.

And you will have thoroughly killed everyone in the area. The 500 rem rad dose ring is 1.18km, the 5psi overpressure ring is 1.33km, and the 3rd degree burn radius is 1.43km, so basically everyone within three quarters of a mile of detonation is going to be dead from direct rad exposure, from direct thermal exposure, and from the buildings collapsing on them.

The fatality rule of thumb is to calculate the distance that the air overpressure from the shockwave is 5psi or higher and count everybody inside that circle, and call them dead. In reality, many inside that ring will survive, but many outside won't, and the idea is that it balances.

With small nukes, however, this breaks down. There are three big "circles" where bad things happen -- the 5psi overpressure line, when most building will be destroyed, the thermal line, where everything exposed to the fireball receives 125J/cm² and burns, and the 500 rem line, where direct radiation from the bomb is almost certainly lethal.

These rings scale differently with weapon size. For small bombs, the radiation circle is likely to be the dominant factor. Above 3kt, the thermal ring becomes the largest, and grows much faster with yield than the radiation or blast rings. So, a small bomb kills by direct radiation, the large bomb by fire and blast. So, while a small bomb's direct effects may be smaller in distance, they're likely to be deadlier in effect if you are in that distance, and much less so when you're not.

Finally. If you have a 6-10kt nuke, you are very close to having a 50-100kt nuke -- boosting a fission weapon with a small amount of tritium is not a very difficult thing at all, and tritium is much easier to make than weapons grade uranium or plutonium.

Would there be a noticeable difference in the seismic activity profile of a 6kt nuclear detonation contra 6000 tons of conventional explosive?

Yes. Since the time scale is different -- a 6kt weapon would release all of the energy in nanoseconds, while 6,000 tons of chemical explosives would take many microseconds, you get a different frequency profile. The effect is harder to see with smaller nuclear explosions. Another factor is the area of impulse. All of the energy of a nuclear weapon is released from a very small area, but 6000 tons of high explosive fills a much larger volume of space.

You *might* be able to muffle the signature of a nuke enough by firing it in a very large underground cavern, so that the blast would first compress the air, then start moving rock. This gets much harder as the yield increases, because you need an implausibly large cavern.

The other confirmation is looking for short-lived isotopes in the atmosphere -- even if the explosion was underground, you rarely get a perfect seal. You can bet those planes are flying right now.

Nuclear weapons test monitoring also involves satellites looking for gamma rays, although that doesn't help for underground tests.

Most gammas generated in the burst won't even make it 20 miles up, never mind space. Detecting a surface explosion is vastly easier -- you look for a very specific nuclear signature, the double flash. When the bomb explodes, at first, it produces a *very* bright point of light, from the very tiny but very hot (and growing) fireball. Shortly thereafter, the shock wave grows larger than the fireball, and refraction greatly reduces the amount of light that gets through, until the shockwave weakens and slows below supersonic speed. So, you get a very distinct light curve -- from a very small area, you get a very bright, then dim, then very bright light, with the latter light slowly decaying.

This is why the Vela incident still confounds -- the visible signature screamed nuclear detonation, but because of the location (in the South Atlantic) nothing else was there to confirm.

In one of those ha-ha only serious moments, one of the first instruments for detecting this pulse was the Bhangmeter. They're basically one pixel cameras, measuring the total flux of light, and they look for the double flash.

Above about 20 miles, you don't get the double flash -- there's not enough atmosphere for the shockwave to create the refractive effect. You can see a smaller version of the effect on Mythbusters when they do a high speed shot of a large explosion.
posted by eriko at 5:47 AM on February 12 [25 favorites]

So, no... there is no magic bullet against DPRK artillery and long range missiles. Rhinemetal HEL laser emplacements may fill that role, but we're around 5-10 years from the deployment of a useful system.

During which time this chubby little shit will grow fatter and who knows how many more of his royal subjects will starve to death.

What's the math on that? Would we lose more people (regardless of which side of the border they live on) by attacking North Korea's military now or by waiting for North Korea to fall apart or have a change of heart?
posted by pracowity at 5:56 AM on February 12

The nuke doesn't matter. The size of the army does.

NK has the world's 4th largest standing army and nothing to lose by using it.
posted by prepmonkey at 5:58 AM on February 12

The nuke doesn't matter. The size of the army does

I've been told that size doesn't matter, it's how you use it that counts. Applying that logic to NK, do they have what it takes to go head to head with a juggernaut like the US armed forces?
posted by Sailormom at 6:04 AM on February 12

Applying that logic to NK, do they have what it takes to go head to head with a juggernaut like the US armed forces?

I wish someone had asked this question during one of the Red Dawn production meetings.
posted by (Arsenio) Hall and (Warren) Oates at 6:07 AM on February 12 [1 favorite]

There's half a million scarecrows in Pyongyang who'd give anything for one mouthful of what you got.
posted by pracowity at 6:22 AM on February 12 [1 favorite]

Finally, it's a bit misleading to say 'the bomb was smaller than little boy,' implying that it's not all that great.

I'm not saying we wouldn't get our hair mussed. But I do say no more than ten to twenty million killed, tops. Uh, depending on the breaks.
posted by kirkaracha at 6:25 AM on February 12 [5 favorites]

scarecrows? yowtch. There's got to be a better way to make your point than that.

My second grade class wrote journals today about what they'd do as president of South Korea... MOST of them said unify the North and South. My sixth grade debate class were surprised by the news that it wasn't an earthquake earthquake, but nonplussed to hear about the nuclear test. There've already been two, the third was less exciting than the earthquake story.
posted by nile_red at 6:44 AM on February 12

I've been told that size doesn't matter, it's how you use it that counts. Applying that logic to NK, do they have what it takes to go head to head with a juggernaut like the US armed forces?

I actually wouldn't have guessed that North Korea has the food to feed an army in the field in a conventional war with the United States.

It's sort of a moot point since a totally conventional war with North Korea seems unlikely, but in the event it happens my money is on the US purely for logistical reasons.
posted by Bulgaroktonos at 6:44 AM on February 12

I hope I am not being too naive, but couldn't you fake a 6KT Nuke explosion? Especially one that was underground? Considering that the NKG likes to starve their people I'd assume there would be plenty of Anfro to make a 10kt boom. The Mythbusters did a 5kt one Mybe KJU is trying to make diamonds.
posted by Gungho at 6:45 AM on February 12

Thats 5k pounds, not 5ktons though, right?
posted by jonbro at 6:51 AM on February 12 [2 favorites]

I hope I am not being too naive, but couldn't you fake a 6KT Nuke explosion?

It would probably be easier just to build the nuke.
posted by jaduncan at 6:52 AM on February 12

short version: 6 thousand tons of TNT? That's a *lot* of volume to dig out.
posted by jaduncan at 6:54 AM on February 12

Gungho, (on preview, as jonbro points out) that Mythbuster vid uses 5000 lbs., not 5000 tons. E.g., 2.5 tons, or 0.0025kt. And when you take into account the explosive used, it's roughly the equivalent of 0.0020kt of TNT.

The largest man-made conventional explosion—albeit an accidental one—was estimated to be around 6-7kt TNT equivalent. The largest deliberate ones, about 4kt.
posted by DevilsAdvocate at 6:55 AM on February 12

Most gammas generated in the burst won't even make it 20 miles up, never mind space.

Gamma ray bursts (the astronomical phenomenon) were discovered by classified satellites put up to look for nuclear explosions. They expected a low background but found that every few hours there was a burst of gamma rays lasting from a few milliseconds to tens of seconds. The source of the bursts was a total mystery for decades. It's only in the past ten years that the source has become somewhat more clear, but it's still a controversial subject. One of the leading ideas is that at the end of a very massive star's life, a black hole forms and the center and stats consuming the star from the inside out. This leads to a strong shock and a collimated outflow that produces the gamma rays.

Upon reflection, those original satellites were put up in the 60's, when they were still doing stratospheric tests. So that must have been what they were looking for. It's true that gamma rays produced on the ground aren't going to make it all the way to a satellite.
posted by ngc4486 at 7:04 AM on February 12

link from the hacker news thread:

google maps of the test site on Nuclear Test Rd!

2 moozes brings the "Hwasong Gulag" into the view.

I have no idea (but am v. curious) how those data got into the google databases.
posted by bukvich at 7:55 AM on February 12

Also: wolfram alpha.
posted by bukvich at 7:57 AM on February 12

Counterpoint: Having nukes is not stopping us from bombing Pakistan.
posted by humanfont at 7:58 AM on February 12

I have no idea (but am v. curious) how those data got into the google databases.

Cloudsourced on the Google Mapmaker tool, then finally accepted as DPRK are likely to provide data sometime after the heat death of the sun.

You'll notice some of the countries nearby are blank, as the mapping data is good enough that they don't want the public messing it up. That's why the DPRK names are things like 'x gulag' or 'Nuclear Test Rd'; nobody knows the local name, just the satellite image of the road.
posted by jaduncan at 8:05 AM on February 12

Counterpoint: Having nukes is not stopping us from bombing Pakistan.

We are at least pretending that we have permission from the Pakistani Government to do so.

The largest deliberate ones, about 4kt.

And to give you a sense of the dramatic difference between a 4kt nuclear blast and a 4kt chemical one, see the Minor Scale test, where 4800 tons of ANFO was fired off.

Note how you can see, well, the sky and land, because the fireball is vastly cooler than the same sized nuclear fireball would be. This was known, the test was explicitly to test blast effects, not thermal (which is easier to defend against -- paint a building gloss white, for example) or rad effects.

short version: 6 thousand tons of TNT? That's a *lot* of volume to dig out.

Assuming ANFO, density is about 840kg per cubic meter, or 1850 pounds per cubic meter, or .925 tons. So, 6000/.925 ~= 6500 cubic meters, which means you'd need to dig a cube just over 40x40x40m. Not an impossible cavern to dig by any means in the right material, though I'd expect it to be longer, narrower, and much less tall, call it a drift 800m long, 20m wide, and 4m high, plus change for the last 100 cubic meters -- each extra meter dug would net you 80 cubic meters, so call it 802 meters long.
posted by eriko at 8:21 AM on February 12

China may be becoming less tolerant with its neighbor

Good. I blame the Chinese as much as the Kim family for the plight of North Korea. Their continued support of the regime is understandable geopolitically (look at how close Beijing is to Korea) but it's one of the worse cases of state-sponsored mass murder in human history, going on for generations.
posted by stbalbach at 8:45 AM on February 12 [1 favorite]

I actually wouldn't have guessed that North Korea has the food to feed an army in the field in a conventional war with the United States.

I'd put even money that in the actual event of a conventional NK/SK+US war, the entire noncombatant population of North Korea immediately goes on a ration of nothing at all, with every single grain of rice sent straight into soldiers' mouths. This decision will not even make the top 10 list of Worst Things the Regime has Done.
posted by Tomorrowful at 8:58 AM on February 12 [2 favorites]

Assuming ANFO, density is about 840kg per cubic meter, or 1850 pounds per cubic meter, or .925 tons. So, 6000/.925 ~= 6500 cubic meters, which means you'd need to dig a cube just over 40x40x40m. Not an impossible cavern to dig by any means in the right material, though I'd expect it to be longer, narrower, and much less tall, call it a drift 800m long, 20m wide, and 4m high, plus change for the last 100 cubic meters -- each extra meter dug would net you 80 cubic meters, so call it 802 meters long.

Hmm, I suppose. I'm not sure how it would be seismically in that shape though, since we are wanting this to actually look like a nuclear test. A really long tunnel would probably have delays, and I'm not sure what having multiple primers would do to the blast. I guess you could just have really a lot of primer charges.
posted by jaduncan at 9:01 AM on February 12

I've long wondered if the 1st threat from a crude nuke & crude rocket would be a space blast aimed to damage commercial satellites. How much economic damage would a nuke this size do? Seems like our retaliation would be muted if no lives were directly lost.
posted by tinker at 9:02 AM on February 12

You'd also have to take care of the noble gases and radionuclide releases to match the alleged test.

If you have a nuke design, it probably is just better to build one.
posted by jaduncan at 9:04 AM on February 12

I blame the Chinese as much as the Kim family for the plight of North Korea. Their continued support of the regime is understandable geopolitically (look at how close Beijing is to Korea)

While I am far from an expert on international relations, the way I understand it is as China becomes more of a global leader, North Korea is a continual problem for them. The change in Chinese leadership set to occur sometime in March has stated that one of the regime goals is to better relations with the US and the international community as a whole. This is going to be a continuing issue for them unless they take a hard line stance on it, in addition, North Korea is also unpredictable and while suicidal, China has to consider the possibility of North Korea turning on them. Also, if you believe Wikileaks, there was a memo leaked that China would support an Korean reunification provided US troops didn't cross the current DMZ border.

I have no idea how this will play out but I find it hard to believe that as China continues to strive to be a global leader, they will continue to support a country so unpredictable and despised international as North Korea. While China is far from perfect on the human relations scale, they are always taking it on the chin when North Korea goes off the deep end like today. It's a new black eye for their support every couple of months.
posted by lpcxa0 at 9:08 AM on February 12

This video from the DPRK's youtube seems to be related. I can't understand a word but there is an underground cavern, an enemy, and something analogous to an earthquake.

Can anyone provide the gist of the translation?
posted by sarae at 10:09 AM on February 12

I sure hope the next Call of Duty has something to say about this. Call of Duty is where I get all my international news.
posted by turgid dahlia 2 at 12:21 AM

How has nobody linked the North Korean propaganda video that uses footage from Call of Duty to show America being nuked? It was released a day before the bomb test.

Mercenaries had you fighting in North Korea.

I don't understand why we don't just nuke North Korea before they do something to us.
posted by Charlemagne In Sweatpants at 2:08 PM on February 12

If by "us" you mean the United States, don't worry. Seriously. North Korea can't and isn't going to attack us.
posted by (Arsenio) Hall and (Warren) Oates at 2:32 PM on February 12

Charlemagne In Sweatpants, because of this (and, amusingly, nothing here has changed since 2006):

"- Reasons Why Neither Side Will Start A Serious Shooting War In Korea -

The North Koreans: I will not attempt to analyse the possible motives of the DPRK, other then to avoid the internal collapse of the regime, and therefore of the Juche system.

First among these is the massive amount of landmines around the DMZ, meaning that no units can even have the possibility of crossing on to each foreign territory via land on their own initative. This route to war is therefore closed off. To do an invasion/incursion, you have to carpet bomb the border to clear a path. This is known by both sides, and so the only situation in which this is likely to be done is all out war. So not the first step then. Assuming they did start doing this, and that any conflict for the DPRK is magically guaranteed conventional, let's see how this turns out for the DPRK forces.

They have:
20 MiG, and about 8-900 other 70s-80s mainly Soviet planes. It should be noted that the country has a massive oil crisis, and many are likely unmaintained, or have been canibalised for parts.
1.08 million troops. This is a formidable number, but it should be noted that these men do not possess modern equipment in the main, or more crucially, modern C&C networks. There are shades of the Iraqi Army in Gulf War I here, and they got pasted.
55,000 special ops. These are well trained, well equipped (for task) troops, who do not face massive problems with C&C as they are designed to operate behind enemy lines in a semi-partisan role. These are likely to be a very effective constant irritation, but people doing asymmetrical warfare without support from the local population can only be an irritation, as they cannot shrink into that population to hide.

They would immediately face around half a million ROK troops armed with modern US supplied kit, the 17 thousand US troops that are already in the ROK, the ROK navy, and probable nuclear subs in the area. They would very soon face US troops from the Japanese bases also, and nigh-limitless air cover. While the DPRK has such a massively fortified country (photos on request) that it would be very easy for them to make an invasion costly beyond any reasonable cost for ROK/US, it is by no means certain that they would have the ability to hold the South Korean ground. One of the most crucial things here is the comparative industrial ability to provide ammunition that even *all* of a war-ruined Korea could provide compared to US forces. So, conventional war results in a massive loss, and probably a complete collapse of an already-on-the-deathbed internal economy.

A nuclear conflict also has no gain for them in power terms. Bear in mind that their nukes are the only thing in their locker: the conventional stuff is all somewhat outdated, representing the materiel that the USSR and PRC felt comfortable giving them, and was much the same carefully obsolete stuff the US give to second string allies. We can take it as read that a limited DPRK first nuclear strike of any kind would result in a massive retaliation on all sites where nukes were still suspected (suspected? Maybe just idly considered possible) to be stored, leaving the DPRK with no real assets to prevent further military response. This means they are faced again with a rather binary option of launching all they have, or having most of their nukes blown up within the DPRK. This is much the same dilemma that resulted in Soviet nuclear planning revolving around a full scale nuclear attack or nothing.

The major reason that this is so unpalatable to the DPRK when compared to Soviet military planners is that the Soviets had a chance of knocking out a significant percentage of the US nuclear arsenal. The DPRK has (unbelievably generously) 15 nuclear warheads. With this it can reliably level the ROK, and *might* be able to get a nuke on Japan. At this point it is faced with the US as main adversary, nuclear subs that each carry more warheads then the DPRK's entire arsenal, and no possibility of strike on that adversary. This means that a real nuclear war results in them being obliterated.

Why we won't start it: We are well aware that the DPRK know that their only real big card is the nuclear issue. This is what they see as their ticket to both continuing aid, and to avoiding invasion. For this reason, there is next to no chance of us attempting to strike at the only targets that we care about, the nuclear sites. The risk of a preventative missile strike being detected and causing the DPRK to launch the threatened missiles is far too high for the payoff. In addition, we would then face the scenario of having started a conflict where we were unaware that the DPRK had another warhead storage point we were unaware of. Also consider that this is highly likely given that DPRK political planners know that they face a massive disadvantage in an air war, and have no practical way to stop an air strike from a B2, for example. Given the massive concentration of troops on the border, we also would face the likely loss of ROK lives numbered in the hundreds of thousands in even a short conventional war. Any US or ROK president has to be aware that this is not likely to be massively loved by the people at home, and neither party wants to be involved in the massive, massive problem that would be administrating the DPRK as an entity even if all military forces on the Northern side were destroyed.

You note that you wish there was an easy bright line to watch, but neglect to note that in Korea, there is. Consider that the only open military conflict since the DMZ was created was the killing of Southern-based soldiers who had entered the DMZ to cut a tree down, with this being understood as part of the ritual, and with no meaningful response from either side. This is a highly formalised conflict, with both sides knowing that any major incursion over the DMZ would mean a full scale conflict, with neither side having anything to gain from that resumption. Terrifyingly well armed as it may be, there is a reason that the DMZ is the most stable active conflict military line in history."
posted by jaduncan at 3:09 PM on February 12 [4 favorites]

Well, one thing changed. The DPRK economy is even more screwed than it was.
posted by jaduncan at 3:10 PM on February 12 [1 favorite]

If by "us" you mean the United States, don't worry. Seriously. North Korea can't and isn't going to attack us.

I mean both countries I'm a citizen of; North Korea attacking Australia would probably be easier for them than attacking America.
posted by Charlemagne In Sweatpants at 3:53 PM on February 12

It seems far more likely that we will choose to use one of the regular North Korean provocations as a pretext for launching a war based on our own domestic politics. Then we will discover that we've gotten ourselves into another decade long conflict until t ends under ambiguous circumstances.
posted by humanfont at 4:13 PM on February 12

It seems far more likely that we will choose to use one of the regular North Korean provocations as a pretext for launching a war based on our own domestic politics. Then we will discover that we've gotten ourselves into another decade long conflict until t ends under ambiguous circumstances.

Or we can make an attempt to evacuate most of the people and then nuke the country off the map.
posted by Charlemagne In Sweatpants at 4:15 PM on February 12

Oh, duh. I bet the occasion was the U.S. State of the Union address. Like, "Talk about this, fuckers." And maybe New Year's, a couple days late.
posted by limeonaire at 4:22 PM on February 12

"I mean both countries I'm a citizen of; North Korea attacking Australia would probably be easier for them than attacking America."

If you mean by Australia, then it's because our country isn't ruled by psychopaths (oh and we don't have nuclear weapons).
posted by wilful at 4:58 AM on February 13

Or we can make an attempt to evacuate most of the people and then nuke the country off the map

Yeah, that won't work. It'll still be on the map, just covered in yellow and black stripes and a rad symbol. Tip: same problem with "blowing it off the face of the earth." As to bombing them back to the stone age....well, juche policy seems to be accomplishing that on its own time.

Seriously, its obscene to frame this kind of use of nuclear weapons as a humanitarian endeavor; or even a remotely plausible notion. It's pure nonsense to imagine that you could evacuate North Korea before bombing it. I mean, what? We're just going to trundle up to the DMZ with an endless fleet of parking shuttles and announce "THE LINE TO AVOID NUCLEAR ANNIHILATION FORMS DIRECTLY IN FRONT OF YOUR HOMICIDAL OPPRESSORS' MACHINE GUN EMPLACEMENTS. USA! God Save the Queen!"
posted by snuffleupagus at 3:11 PM on February 13 [1 favorite]

It's pure nonsense to imagine that you could evacuate North Korea before bombing it.

I was assuming that he meant evacuating Seoul and the RoK border areas, given the amount of fallout that would be drifting south. Or it might be drifting north. China would be sure to *love* that.
posted by jaduncan at 11:11 PM on February 13

At least the test site gets mostly good reviews. Adrian Lamo sure gets around.

I'm still mad about Zagat
posted by snuffleupagus at 5:38 AM on February 14 [1 favorite]