California had best take heed: The Geysers and Salton Trough have taken way more heat out of the Earth, and I would argue delayed, shifted, and intensified the big one the Hayward Fault is overdue for.
There's been a great deal of ridicule placed on opponents of geothermal energy, saying that geothermal could never contribute to an earthquake. I'm hopeful the ridicule will start to go away now.
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 ?
Yes absolutely, we're just exploiting potential energy here, and that was my point, perhaps I wasn't clear enough.
That's why the efficiency of the power plant (if this energy would have been captured) would have been a sight to see on paper. The energy they put into the fracking would have been tiny compared to this.
It's unlikely that all of that energy was injected into the earth by humans. The high-pressure fluid injection generated cracks and lubricated the surrounding rock, facilitating a release of existing stresses. The area around Pohang is riddled with faults. There's a lot of energy down there just waiting to be released.
South Korea, like most other developed nations, is trying to increase the use of renewable energy. There are many hot springs in Korea, especially around active faults. Geothermal is an obvious candidate in those areas. Of course they're also doing wind and solar where feasible.
Earth's crust "wants" to move. One thing is triggering an earthquake by fracking, another one is stopping the crust with all the mantle below pushing heat into it. That heat has to go somewhere. I guess the best we'll reasonably do is forecasting quakes.
Hypothetically, if you could cause earthquakes in a controlled way, it may be possible to perform periodic small stress relief quakes rather than allowing one big one to occur naturally. We can't stop it moving, but maybe we can make it move on our terms.
The current government, which ousted the former goverment with absurd scandals, is under a huge bribery and corruption scandal which includes kpop stars, police and prosecutors alike.
The current government always tried to shift the media’s attention when they were in trouble with former government’s incidents and this is one of them.
The government is actually trying to indict former government’s staff and let them take all the media’s blame, while they clean up their own bribery scandal.
Here are the abstracts of the two Science papers. This isn't my area, and although it would be hard to prove causation, they do have good evidence that causation is plausible. That's probably as strong a claim as anyone would be likely to be able to make, given the constraints on what is known.
The moment magnitude (Mw) 5.5 earthquake that struck South Korea in November 2017 was one of the largest and most damaging events in that country over the past century. Its proximity to an enhanced geothermal system site, where high-pressure hydraulic injection had been performed during the previous 2 years, raises the possibility that this earthquake was anthropogenic. We have combined seismological and geodetic analyses to characterize the mainshock and its largest aftershocks, constrain the geometry of this seismic sequence, and shed light on its causal factors. According to our analysis, it seems plausible that the occurrence of this earthquake was influenced by the aforementioned industrial activities. Finally, we found that the earthquake transferred static stress to larger nearby faults, potentially increasing the seismic hazard in the area.
The moment magnitude (Mw) 5.4 Pohang earthquake, the most damaging event in South Korea since instrumental seismic observation began in 1905, occurred beneath the Pohang geothermal power plant in 2017. Geological and geophysical data suggest that the Pohang earthquake was induced by fluid from an enhanced geothermal system (EGS) site, which was injected directly into a near-critically stressed subsurface fault zone. The magnitude of the mainshock makes it the largest known induced earthquake at an EGS site.
"The results support the findings of a pair of studies published in Science1,2 last year, which suggested the plant as a likely cause of the quake."
"Earthquakes have been linked to geothermal power plant in other parts of the world. But the Pohang quake is by far the strongest ever tied to this kind of plant — 1,000 times mightier than a magnitude-3.4 quake triggered by a plant in Basel, Switzerland, in 2006."
If you take the word `purely` out of your statement, it is a political decision. Seems to be based on science though. Everything else becomes irrelevant. This also reminded me about the `fracking` debated in US. If I am understanding this link [0] correctly, it's not the fracturing of the rocks but the high pressure liquids that induces earthquake? I am still unclear on the detailed mechanism.
There's been a great deal of ridicule placed on opponents of geothermal energy, saying that geothermal could never contribute to an earthquake. I'm hopeful the ridicule will start to go away now.
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