North Korea claim to have tested a nuclear bomb

[Nonamer]

It's the top story at news.google.com at the moment. Rather not find some random article to support this though. Anyways, what do you make of it? My first guess is it's a fake. If they want to convince us, do it in an open region and show us a video. Otherwise, there is no reason to believe that they didn't fake it with a very large conventional bomb. The reports indicate a magnitude 4.2 earthquake in North Korea, which I'm getting conflicting data over the energy released. One said it's over 1KT, another more like .03 KT. I'm not sure what to believe, but either one can be faked.

[Jedi Master Spock]

I am inclined to believe that North Korea did indeed set off a small nuclear device.

They announced a few days ago that they would test one, and seismic readings suggest something that would be difficult to produce with conventional explosives. Possible, sure, but think about the history.

They've been working on this for a while; most of the experts I've read from in the past have been guessing that North Korea does indeed have a couple functional devices. Frankly, it's not that difficult to get a nuke built; the main obstacle is getting the fissile materials, and North Korea is usually reported to have stockpiles on hand.

IMO, the most important part is going to be the political fallout in any case, and in looking at that, the working assumption will be that North Korea did indeed detonate a nuke unless detractors can solidly prove otherwise.

With all the evidence sitting in North Korea, that seems pretty unlikely.

[Nonamer]

Now I'm getting half a kiloton from various sources. That's well belowed the threshold for a real nuclear device (it's a sub-critical yield). Fat Man was 20+ KT for instance, and there are others ones much larger than that. Something smaller like Little boy doesn't need testing as it's just slamming two pieces of enriched uranium together so they would not test such a thing. There's also the possibility of a failed nuclear device. Basically a bomb that fails to detonate but becomes a molten blob of plutonium that melts through the floor and explodes when it hits groundwater. This is basically what happens in a nuclear meltdown. The siesmic event actually supports this as it's much too long for a normal nuclear detonation.

[Jedi Master Spock]

Well, the point of a North Korean test of a "Little Boy" type device wouldn't be to see if it actually worked - for that matter, I don't think that would be their motivation in any case. It's pure political demonstration.

As usual, the fastest way to find out what figures are flying around and why is, of course, the wonderful Wikipedia. Here you can see a quick breakdown of the figures.

Basically speaking, the 3.5-3.7 richter measurements reported by South Korea corresponds to the estimate of 550 tons (also out of SK); the South Korean geologists have now uprated their estimates to 800 tons.

The USGS measured the event as a 4.2 Richter, which is to say an event several times stronger than what the South Koreans estimate. I can't find an exact source, but the Russians have apparently published a 5-15 kt estimate.

It all depends on which geological services you trust most to be accurate at this point. The Russians definitely have the most practice in measuring the seismic waves from known nuclear devices detonated in and around that region, the South Koreans are the closest, and the USGS is reporting a result that an American agency would have a good motive not to report.

One thing this is a good demonstration of is the difficulty of gauging yield of a weapon through purely extrinsic means. Without knowing more about the device and the precise conditions it was set off in, it's hard to pin the weapon down to more than a general order of magnitude.

[Skinofevil]

Skinofevil isn't worried about The Daewoo Empire coming up with a working nuke. If Skin doesn't worry about it, neither should you. Remember that this is the land of televisions with warranties that expire when the customer leaves the store.

Skin predicts that the first -- and last -- North Korean launch of a nuclear weapon will result in the immediate and thorough deletion of the launch facility and every scientist, technician and military person in attendance.

North Korea may be dancing merrily about, disturbing millions of belly-fuls of kimchee (which is the only North Korean weapon to merit any concern or apprehension) at the idea of sending the Pacific Rim into fits of terror to be followed by a mad rush to appease them. But Skin knows, and now so do you, that after a North Korean (attempted) nuclear strike, the world will be left with a good chuckle and more real estate for building prisons.

[Jedi Master Spock]

But Skin knows, and now so do you, that after a North Korean (attempted) nuclear strike, the world will be left with a good chuckle and more real estate for building prisons.

They've been spending the last half century bankrupting themselves to develop their military. A "good chuckle" will only be had by those who find body counts funny, and we'll be lucky if it stays on the Korean peninsula. Even a 4 kiloton device - as the North Koreans have been claiming and as the 4.2 Richter reading more or less confirms - could do an awful lot of damage if it ended up somewhere in Tokyo.