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---- From the article: A South Korean government panel has concluded that a magnitude-5.4 earthquake that struck the city of Pohang on 15 November 2017 was pro
by reallymental 8y ago
---- From the article:
A South Korean government panel has concluded that a magnitude-5.4 earthquake that struck the city of Pohang on 15 November 2017 was probably caused by an experimental geothermal power plant....
Unlike conventional geothermal plants, which extract energy directly from hot underground water or rock, the Pohang power plant injected fluid at high pressure into the ground to fracture the rock and release heat — a technology known as an enhanced geothermal system....
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This is both horrifying and incredible. They managed to fracture enough rock to generate energy contained in a mag-5.4 earthquake.
That's around 200 KT of TNT [0].
That's a lot of useful energy if contained. I wonder what the efficiency of the plant would be then.
South Korea already has 23 nuclear plants though [1], I wonder why they decided to go this route, perhaps easier setup and lower associated costs ?
[0] https://science.howstuffworks.com/environmental/energy/energy-hurricane-volcano-earthquake3.htm https://science.howstuffworks.com/environmental/energy/energ...
[1] http://www.world-nuclear.org/information-library/country-profiles/countries-o-s/south-korea.aspx http://www.world-nuclear.org/information-library/country-pro...
- onetimemanytime 8y ago>>This is both horrifying and incredible. They managed to fracture enough rock to generate energy contained in a mag-5.4 earthquake. It was probably hanging in a balance. Then boom!
- acidburnNSA 8y ago> South Korea already has 23 nuclear plants though [1], I wonder why they decided to go this route, perhaps easier setup and lower associated costs ? Despite South Korea being among the only countries that can currently do successful large nuclear builds, South Korea's government is fairly anti-nuclear, reflecting fear of the public post-Fukushima [1]. This is really sad because the skilled workers and construction management expertise required to accomplish this are very rare, and this team could be instrumental in very rapidly decarbonizing the world if deployed strategically. S. Korea also has some of the best shipyards. Turning them into assembly lines for GW-scale nuclear plants (floating or embanked) is one of the more interesting ways to rapidly and cheaply build out terawatts of clean, safe energy [2]. [1] https://www.theguardian.com/world/2017/jun/19/new-south-korean-president-vows-to-end-use-of-nuclear-power https://www.theguardian.com/world/2017/jun/19/new-south-kore... [2] https://news.mit.edu/2015/new-look-floating-nuclear-power-0624 https://news.mit.edu/2015/new-look-floating-nuclear-power-06...
- madez 8y agoA floating nuclear plant sounds like of one the most dangerous things a society can do. One of the problematic aspects of atomic fission energy plants are their failure behaviour. One of the most important aspects there is the containment of the pollution (in Fukushima they literally freeze the ground water under the plant so it is contained from below, too). If you are free floating in water, possibly even an ocean, you are about as uncontained as you can possibly get.
- azeotropic 8y agoThe U.S. Navy seems to operate a bunch of floating (and some submersible) nuclear power plants in the ocean without too much trouble.
- madez 8y agoWithout too much trouble that we know of. And a small number of small reactors. I think it is extremely irresonsible to build military equipment with nuclear reactors. They are destroyed in conflict, polluting everything.
- fucking_tragedy 8y agoCorrect me if I'm wrong, but I'm pretty sure the scale is much different.
- acidburnNSA 8y agoNot too different. Subs can be a few hundred megawatts, vs. a few thousand in power plants.
- bronson 8y agoOnly an order of magnitude or two.
- 8y ago
- ajross 8y ago> They managed to fracture enough rock to generate energy contained in a mag-5.4 earthquake. No, they managed to fracture enough rock to destablize the system and allow the fault to slip and release the energy it had built up over decades. In effect, this pulled the trigger. The energy was in the action, which was cocked by the earth.
- timerol 8y agoWhile true, it's mostly pedantic. OP is talking about a potential earthquake harvesting power plant. So generating in this sense means releasing the trigger, in the same way that burning coal is generating energy. It's just releasing the stored chemical energy of the coal, but we still say that coal powerplants generate energy.
- kbenson 8y ago> This is both horrifying and incredible. They managed to fracture enough rock to generate energy contained in a mag-5.4 earthquake. Or they fractured enough rock to cause what would have been an earthquake of magnitude >= 5.4 at a future date to happen at that time, which I think is more likely. As I understand it, earthquake's are opposing forces of tectonic plates that finally overcome their coefficient of friction. Affecting that coefficient of friction slightly could cause it to happen sooner or later.
- gpm 8y agoAlternative alternative explanation: they caused what would have been 4096 magnitude 3 earth quakes (0.2 magnitude difference corresponds to 2x energy per wikipedia) to merge together into a single magnitude 5.4 earthquake. Since they reduced the coefficient of friction enough to allow all that energy out at once instead of in small steps.
- andromeduck 8y agoReducing static friction results in more frequent releases of the same energy.
- gpm 8y agoAssuming the energy input is constant that would be impossible. Why is the energy input non constant? Is static/dynamic friction even a semi-accurate model for plate tectonics?
- Scramblejams 8y agoI had a physics professor whose day job was geophysics. We were discussing earthquakes, and he said he really wanted to investigate the possibility of eliminating the threat from the San Andreas fault by intentionally triggering it at some regular interval, before the opposing forces built up to dangerous levels. He was onto something!
- kenneth 8y ago
- stuaxo 8y agoWell, the energy is already there, the fracking will have lubricated the rock enough that it could release the energy.
- ChuckMcM 8y agoI was thinking about the same question and came at it from the other side, which is "How big a plant and how far away do you have to situate it to destroy a city?" Which is to say, what would someone need to do to weaponize geothermal fracking? Urban warfare is siege warfare and being able to knock down the castle without having to expose yourself to enemy fire would seem to be an advantage. The fault lines would need to co-operate too of course.
- Qwertystop 8y agoDistance and size of plant would also be heavily dependent on the fault lines. Could be a very useful military tool for attacking particularly vulnerable places (if you can fortify a nearby position against enemy attack for long enough to build such a thing). Seems overly-situational without some extremely rapid assembly. Good for softish sci-fi, though!
- dontbenebby 8y ago>South Korea already has 23 nuclear plants though [1], I wonder why they decided to go this route, perhaps easier setup and lower associated costs ? Atoms scare uniformed voters.
- adambyrtek 8y agoI guess you meant "uninformed" not "uniformed"?
- dontbenebby 8y agoYes. I must missed a key, and it looks like it's been too long to edit the mistake.
- Teknoman117 8y agoDid they actually manage to pump that much energy in it, or was it that they disturbed the fault enough to cause it give?
- baybal2 8y agoThey did not generate that energy, better to say, they liberated it.
- LifeLiverTransp 8y agoThe energy stored in the fault was already there pent up. They just released it. Which if you actually look at it from a damage perspective. Might be sensible. Not allow those mega-nukes like the san andreas fault to build up tons of energy. Instead frack vibrate the fault loose in lots of micro quakes.