With North Korea’s test, I can’t help but wonder what such explosions are doing to the ground in which they take place.

How contained is the radioactivity? What long-term and short-term effects on the soil are there? Or do the effects even reach that high up?

What about the geological effects? Are we creating artificial fault lines or weakness in the earth’s layer that could ‘herniate’ later?

Is there any effect at all on the atmosphere?

I dont know but assume there must be some research somewhere as the yanks and russkies have been detonating them for years 8)

As of 1993, worldwide, 520 atmospheric nuclear explosions (including 8 underwater) have been conducted with a total yield of 545 Megaton (Mt): 217 Mt from fission and 328 Mt from fusion, while the estimated number of underground nuclear tests conducted in the period from 1957 to 1992 is 1,352 explosions with a total yield of 90 Mt.[4]

[video]https://www.youtube.com/watch?v=LLCF7vPanrY[/video]

there must be some research somewhere as the yanks and russkies have been detonating them for years

Of course the UK will have the same data too, or were our bombs ‘special’

It does lead to a rise in background radiation levels. Dunno if its still being done but they used to take metal from the German fleet sunk in scapa flow to use for some sensitive instruments as the steel was made prior to nuke testing so was uncontaminated.

Personally I believe its one of the factors behind the increase in cancers – but scientific opinion is divided on this.

The story is that it was Chernobyl, which released massive quantities of nuclear material into the atmosphere, that meant you have to chop bits off the German battlecruisers in Scapa Flow if you want uncontaminated metals.

I first heard this pre chernobyl

Not sure about the atmosphere,but when the UK were testing them my mates dad had to check the effect on the paint on strategically placed Land Rovers!!
Different times.. 😯

It does lead to a rise in background radiation levels.

Not to any significant level now. If you live in Cornwall, Radon gas is a much bigger risk…..

Frequent above-ground nuclear explosions between the 1940s and 1960s scattered a substantial amount of radioactive contamination. Some of this contamination is local, rendering the immediate surroundings highly radioactive, while some of it is carried longer distances as nuclear fallout; some of this material is dispersed worldwide. The increase in background radiation due to these tests peaked in 1963 at about 0.15 mSv per year worldwide, or about 7% of average background dose from all sources. The Limited Test Ban Treaty of 1963 prohibited above-ground tests, thus by the year 2000 the worldwide dose from these tests has decreased to only 0.005 mSv per year.[33]

What about the geological effects? Are we creating artificial fault lines or weakness in the earth’s layer that could ‘herniate’ later?

Forming large, man-made bodies of water is enough to cause earthquakes and effect existing faults, so nuclear testing certainly could as well.

With regard to forming new faults: Possibly, if the crust was thin enough. As it is, continental crust varies between 30 and 70km thick, on average, with high mountainous regions being ~100km thick, so I’m not sure it would be enough to form new faults, deep enough to rupture: exploit and worsen existing ones? Yes, I can see that as a possibility.

I was wondering what happens in the ground where the bomb actually goes off… do you end up with a spherical hole surrounded by fused rock? Does the shock go through the rock rather than create a void? What would you find if you dug down to where a bomb had gone off (other than your face melting, probably)?

Are we/they/whoever sure now that they’ve actually got Nuclear bombs, last I heard it was thought they were setting off massive piles conventional explosives to try to recreate the effect.

[/quote]I was wondering what happens in the ground where the bomb actually goes off… do you end up with a spherical hole surrounded by fused rock? Does the shock go through the rock rather than create a void? What would you find if you dug down to where a bomb had gone off (other than your face melting, probably)?

It creates a large overpressurised void at the site of the test. Once this starts to cool the cavity collapses inwards, typically within a minute of the explosion. This results in a large crater at the surface, most of these still being visible. Google images ” Nevada desert nuclear test”

I know this because I read it somewhere 😀

they used to take metal from the German fleet sunk in scapa flow to use for some sensitive instruments as the steel was made prior to nuke testing so was uncontaminated.

Really? I don’t think you can ‘make’ other things intrinsically radioactive. Contamination is when traces of radioactive material end up on other things. For steel to become radioactive you’d have to have a radioactive material somehow incorporated into the making of it. For that to be higher than the radioactivity in the other stuff that’s naturally occurring and might be in steel (carbon-14 for example) it’d have to be quite a lot I’d have thought.

EDIT bugger me

However interestingly that article says that whilst airborne radioactive particles have decreased hugely since the 60s some of the metal still contains them because it’s been being recycled ever since then.. cool.

not really weapons testing.

but armour piercing ammunition leaves a lot of contamination in conflict zones

an not as much as Fukushima is going to perhaps…

not to mention all the old leaky dumps storage facilities.

still better to blame the commies.

I know this because I read it somewhere

You are indeed correct, and the results are indeed mental!

the bit that worries me is that what if they have a disaster at one of their sites that produces the warheads. If rich and normalised countries such as Russia and Japan struggle to deal with nuclear disasters, imagine what N Korea with no infrastructure, probably no standards or back up plans or international support won’t manage

You mean like this? Just don’t swim in the lake.

Depleted uranium birth defects are becoming a huge issue for those involved (ie either doing it or living nearby) in modern tank and armoured vehicle based warfare. The images and reports coming out of places such as Iraq are extremely distressing.

Unedited video of test detonations and delay before the cavity collapses.

[video]https://www.youtube.com/watch?v=RE4pwEjPTVc[/video]

For the effect on background radiation, this sums it up nicely: I.e. a tiny percentage of a small percentage of a small amount. It’s the bananas you need to watch out for…

The less radioactive steel and lead thing always amuses me. The detectors used in primary standardisation of radioactive materials at NPL (they who define what units actually are, measuring single counts per second when we cheerfully inject 600 million times that much into people for bone scans) are shielded with lead bricks made out of the old roof of Hampton Court Palace, and in Sheffield we’ve got a whole body counter made from steel from a previous HMS Sheffield (not sure if coincidence or not – expensive before you have to name then decommission your own battle ship). Sadly it turns out being made from ultra-low background materials is little help when someone breaks a Cs-137 source inside the damn thing, so we don’t use that anymore.

That video is mildly perturbing.

You are indeed correct, and the results are indeed mental!

I worked for an engineering contractor at the Nevada Test Site during the underground nuclear test era and have seen the whole area on the ground. Very interesting to see up close and kind of overpowering as well

I really want to visit the sedan crater, looks like something from the moon…

(the entire plowshare project was such a brilliant combination of genius, ambition and complete and total idiocy… Little unresolved matters like “do we even need a deep water harbour in Alaska? No?”. But the other things that seemed like super ideas- “we’ll use it to knock drinking water aquifiers together” “we’ll build a canal across nicaragua” “We’ll flatten a mountain range to build an interstate”, and my personal favourite, atomic fracking…

“oh, well, to be honest, nuclear weapons only have evil applications.”

I’ve found this:

Analysis of local seismic recordings (within a couple of miles) of nuclear tests at the Nevada Test Site shows that some tectonic stress is released simultaneously with the explosion. Analysis of the seismic wavefield generated by the blast shows the source can be characterized as 70-80 percent dilational (explosive-like) and 20-30 percent deviatoric (earthquake-like). The rock in the vicinity of the thermonuclear device is shattered by the passage of the explosions shock wave. This releases the elastic strain energy that was stored in the rock and adds an earthquake-like component to the seismic wavefield. The possibility of large Nevada Test Site nuclear explosions triggering damaging earthquakes in California was publicly raised in 1969. As a test of this possibility, rate of earthquake occurrence in northern California (magnitude 3.5 and larger) and the known times of the six largest thermonuclear tests (1965-1969) were plotted and it was obvious that no peaks in the seismicity occur at the times of the explosions. This is in agreement with theoretical calculations that transient strain from underground thermonuclear explosions is not sufficiently large to trigger fault rupture at distances beyond a few tens of kilometers from the shot point.

A 1968 Nevada test produced a fault 1200m long, with seismic waves from the fault being less energetic than those produced by the bomb test itself.

Some have tried to link the Afghanistan quake with tests by India and Pakistan, as the epicentre was within 1000km of the test sites. Tests had occured 2-20 days before the earthquake. However, these claims have largely been dismissed as the force they produced were small compared to the strains on the crust resulting from the gravitational pull of the sun and moon.

No resulting earthquakes have been observed following the detonation of larger nuclear bombs, either.

Interesting stuff, although the risks for large scale faulting appear to be minimal. Unfortunately, the source book is very hard to get hold of.

When archeologist s talk of “he died 5000 years ago” they usually mean 5000 years BP where BP means Before Present. That “Present” is effectively the year 1953 which is a baseline for radiocarbon dating of organic materials. It’s not possible to use a baseline more recently than early 1950s as organic material formed since then has Carbon12/13/14 ratios that are all over the place due to airborne nuclear testing in 50s.

Interestingly the Carbon12/14 ratios started drifting in Victorian times as a result of coal burning, but that factor -the “suess effect” – can be corrected for when Radiocarbon dating, although the nuclear explosions thing can’t be.

As I understand it one of the reasons that Nuclear testing was moved under ground was to reduce the amount of radioactive daughter nuclie being released into the atmosphere.

john as I understand it you pie charts a back ground radiation exposure for a human. An instrument wouldn’t have any food or medical exposure. The radon could also be easily eliminated from an experiment. So the contribution of other sources would be proportional greater

I guess it’s worth pointing out that underground nuclear detonations can’t “cause” earthquakes, but merely be able to release them a bit earlier than they would have occurred anyway (which is probably safer as the shock magnitude will be lower) This is because an earthquake is the sudden release of shear strain built up by plate tectonics in the upper crust, so that strain has to be there prior to any earth quake. Natural earth quakes occur when that strain exceeds the strength of the friction in the fault faces, and they suddenly slip past each other. So if un-natural vibration or strain is applied, it could only result in a joint slipping before it would have done so naturally. As the detonation shock wave is broadly a normalised radial shock it is highly unlikely, except on very a local scale (ie the blast crater itself) to actually cause significant fault strain across a long enough distance of a fault to cause an earthquake that wasn’t going to happen eventually otherwise.

(imo, IANAG :lol:)

I’ve just started reading this:

It’s a fair old weighty tome!

That is one of my favourite all time books. It’s fascinating. You should follow up with Dark Sun, also excellent. The other ones in his series are good, but a bit niche.

When we do succeed in wiping ourselves off the face of the earth, any future humanoids will have to rely on documentary evidence to do their archaeology. Nothing later than 1945 will be able to be carbon dated as the nuclear testing permanently screwed the ratios of the isotopes of carbon that make dating possible.

You’ll be able to date it to “older than 1945”

Thats one of the reasons why they are proposing to start the Athropocene epoch at the beginning of the nuclear age.

Archaelogists of the future will have it easy

They’ll be able to date everything to within about 6 months with a simple chart of Apple products releases

+1 for Dark Sun.

Chilling in places, especially the bits where the US was deliberately flying bombers past the “point of no return” to try and provoke a reaction because they thought they could win WW3 with acceptable losses (basically Western Europe and a few US cities).

He had better hurry up with those tests as when Corbyn gets in he will be round to persuade him to give them up, along with everyone else.

You also need to consider the social effects. The people of bikini atoll agreed to the Crossroads test programme “to end all wars and for the good of all mankind”. Since then they’ve been treated pretty badly by the US, now living crammed onto kili where they can’t live as they used to, and the elders are dying and taking the nations traditions with them. The people of rongelap shouldn’t have been affected but a shift in the wind didn’t delay the test and later the kids of rongelap were playing in the snow – the radioactive fallout settling on their island. Enewatak came off slightly better as the US eventually bulldozed the topsoil to one end of the island and covered it with a concrete dome, so at least the locals could be resettled. The bikinians went home for while in the 70s but had to leave due to ingesting radioactive material from the food grown in the topsoil. One of the weirdest things about bikini is that the US replanted all the palm trees after the tests, but being military they did it in a perfect grid system.