3 ms·

Comparison of Mount Saint Helens Volcanic Eruption to a Nuclear Explosion (1980)

1 points by Kye 2y ago

watersb 2y ago
Says that such a comparison is not useful to the military, because the blast of the eruption was mostly subsonic gas, dust, and mud, rather than the supersonic plasma of a nuclear weapon. However, I wonder if there is any use in estimating the power - thermodynamic work - required to equal this cataclysm in terms of nuclear weapons. Perhaps not, because the number criticized in the abstract - 10 to 20 megatons - could be meaningless. A 20-megaton bomb might alter the shape of a mountain, if strategically placed where it could do the most work. But maybe you would need multiple such devices to move the same amount of mass as this volcanic eruption. It might not be possible to do with bombs -- more devices could result in just a higher temperature of rock that refuses to cooperate with you. Mechanically coupling all of the energy of the bombs might require an unrealistic amount of vibranium. Which is yet another reason not to mess with Wakanda.
ggm 2y ago
Explosions are by comparison to an atomic event drawn out and slow. Man made Fission and Fusion in bombs is both rapid, and different by quality. Explosions exert energy in chemistry and have low to no electromagnetic/RF component. Nuclear events emit immense amounts of x Rays and other electromagnetic forces which in turn create heat energy in things they interact with, but are also energetic in themselves and then compounding it, are the chemical and physical force effects which are Explosion like in effect and outcome but follow. As was pointed out to me below, sub-critical fission happens all the time, naturally. It might be better to compare nuclear, and the part of an event where a lot of explosive gas and preheating happens like a massive methane gas release, with a surge in temperatures and then a conflagration. So more like a pyroclastic lehar at speed than a classic explosive volcano cone event. Pick your volcano? Well no: St Helens had several pyroclastic flow events. So maybe.. the comparison stands? Doesn't make much difference if it's 100ms or 2s when it comes down to it, rapid disassembly is coming your way.
- defrost 2y ago
  > Nuclear events emit immense amounts of x Rays and other electromagnetic forces which in turn create heat energy in things they interact with and, for a real world example, massive slabs of granite rock that make up the landscape in many parts of the world have large numbers of Nuclear Events occuring every second - the decay of primordial radionuclides and their daughter products warms the rock, releases radon gas, creates "new" lead, etc.
  - ggm 2y ago
    In this case, very slowly. that is, slowly compared to a high speed fission or fusion event. the large number of nuclear events are not in a chain reaction. They're happening in a disassociated manner throughout the matrix of the granite. I think in context it matters because the intensity of event, as a moving surface expanding out from what we might as well consider a point source, is why the army wants the bomb in the first place. If they made the same amount of energy be released over 10 years, distributed in a field of granite I don't think it would help their tactical aims. (Their strategic aims are met by not using the bomb) (please don't come here to pedant that 10 years isn't enough time to do the same energy release as a 20 megatonne event, in that field of granite. the point is, its more than milliseconds not how many decades it happens over. If on the other hand, you can heat a field of granite 400C in an hour or so and not irradiate the area, then the geothermal community would like to talk to you. if you can do it in 20 seconds then the Army is interested again.)
    - defrost 2y ago
      Sure, I raised the example as you might want to modify your GP comment to stress you're talking about above critical Nuclear Events which are extremely rare on Earth, especially compared to the immense number of sub critical Nuclear Events that have occurred here throughout the past 4+ billion years and are still ongoing. I understand the excitement that goes with an atomic bomb explosion, I've been present at some of the last physical bomb tests and have mapped the sites of a number of past tests with airborne radiometric spectrometers.

1 points by Kye 2y ago

Says that such a comparison is not useful to the military, because the blast of the eruption was mostly subsonic gas, dust, and mud, rather than the supersonic plasma of a nuclear weapon. However, I wonder if there is any use in estimating the power - thermodynamic work - required to equal this cataclysm in terms of nuclear weapons. Perhaps not, because the number criticized in the abstract - 10 to 20 megatons - could be meaningless. A 20-megaton bomb might alter the shape of a mountain, if strategically placed where it could do the most work. But maybe you would need multiple such devices to move the same amount of mass as this volcanic eruption. It might not be possible to do with bombs -- more devices could result in just a higher temperature of rock that refuses to cooperate with you. Mechanically coupling all of the energy of the bombs might require an unrealistic amount of vibranium. Which is yet another reason not to mess with Wakanda.

ggm 2y ago

Explosions are by comparison to an atomic event drawn out and slow. Man made Fission and Fusion in bombs is both rapid, and different by quality. Explosions exert energy in chemistry and have low to no electromagnetic/RF component. Nuclear events emit immense amounts of x Rays and other electromagnetic forces which in turn create heat energy in things they interact with, but are also energetic in themselves and then compounding it, are the chemical and physical force effects which are Explosion like in effect and outcome but follow. As was pointed out to me below, sub-critical fission happens all the time, naturally. It might be better to compare nuclear, and the part of an event where a lot of explosive gas and preheating happens like a massive methane gas release, with a surge in temperatures and then a conflagration. So more like a pyroclastic lehar at speed than a classic explosive volcano cone event. Pick your volcano? Well no: St Helens had several pyroclastic flow events. So maybe.. the comparison stands? Doesn't make much difference if it's 100ms or 2s when it comes down to it, rapid disassembly is coming your way.

defrost 2y ago
> Nuclear events emit immense amounts of x Rays and other electromagnetic forces which in turn create heat energy in things they interact with and, for a real world example, massive slabs of granite rock that make up the landscape in many parts of the world have large numbers of Nuclear Events occuring every second - the decay of primordial radionuclides and their daughter products warms the rock, releases radon gas, creates "new" lead, etc.
- ggm 2y ago
  In this case, very slowly. that is, slowly compared to a high speed fission or fusion event. the large number of nuclear events are not in a chain reaction. They're happening in a disassociated manner throughout the matrix of the granite. I think in context it matters because the intensity of event, as a moving surface expanding out from what we might as well consider a point source, is why the army wants the bomb in the first place. If they made the same amount of energy be released over 10 years, distributed in a field of granite I don't think it would help their tactical aims. (Their strategic aims are met by not using the bomb) (please don't come here to pedant that 10 years isn't enough time to do the same energy release as a 20 megatonne event, in that field of granite. the point is, its more than milliseconds not how many decades it happens over. If on the other hand, you can heat a field of granite 400C in an hour or so and not irradiate the area, then the geothermal community would like to talk to you. if you can do it in 20 seconds then the Army is interested again.)
  - defrost 2y ago
    Sure, I raised the example as you might want to modify your GP comment to stress you're talking about above critical Nuclear Events which are extremely rare on Earth, especially compared to the immense number of sub critical Nuclear Events that have occurred here throughout the past 4+ billion years and are still ongoing. I understand the excitement that goes with an atomic bomb explosion, I've been present at some of the last physical bomb tests and have mapped the sites of a number of past tests with airborne radiometric spectrometers.