In 2017, South Korea suffered the second-worst earthquake in its history, and a recent investigations finds that it may have been caused by humans. According to the government-funded study, the cause of the quake was an experimental geothermal plant in the city of Pohang.
Geothermal plants rely on the Earth’s internal heat to generate clean, cheap energy, which makes them attractive as a way to combat climate change. The geothermal plant in Pohang was one of a handful of experimental plants located around the world that seek to make this type of generation more efficient.
The Pohang plant works by pumping thousands of gallons of water deep beneath the Earth’s surface and into small subsurface cracks. That water is warmed by the Earth’s crust and brought back up to the surface, where the excess heat is converted into electricity. If that sounds familiar, you’re right: That’s very similar to the strategy used by natural gas fracking operations.