[Essay Writing HW#6] Geothermal power generation causing an earthquake

The 2017 Pohang earthquake, in the Southern part of Korea, was a sudden surprise. The earthquake was powerful, registering 5.4 on the Richter scale. The governmental research group discovered that geothermal power generation influenced the earthquake. In theory, academic research shows how geothermal power generation can cause an earthquake.
Geothermal power generation can be defined as making electricity through geothermal heat. As one approaches the earth’s core, the earth becomes hot. In order to generate power using the natural heat from the earth, the plant installed two long pipes into the ground, about 3 to 4 km. One pipe is for sending down water, and the other pipe returns steam. The pipes pass through crude oil and shale gas layers. After the pipes were installed, water was injected deep into the ground. A natural rockbed functions like a pot, the earth's heat turns water into steam. Escaping steam allows the power plant to operate an electrical turbine.
One scenario suggests that geothermal power causes earthquakes relates to water. Wet land is comparatively vulnerable to earthquakes, since water loosens the soil. According to academic research, 10 thousand cubic meters of water could cause a 4.0 Richter scale earthquake. Before the pipes are installed and water in injected, it was assumed that the underground fault was stable. However, stress from injected water may have destabilized the fault. Once water permeates the pores of the fault, it imposes stress on the fault plane. As more water in injected, more stress is applied to the fault plane. As power generation continues, stress accumulates. The condensed stress makes the fault plane slips from its original place. As a result, it leads to an earthquake.
The second mechanism which potentially causes earthquakes is the pipes themselves. Artificial structures deep underground can affect the pressure in the fault plane. The direction of pressure continuously pushes on the fault. Artificial structures, such as pipes which are deep in the fault plane, can cause changes concerning pressure. If the fault plane begins to press on another fault, the interaction of the two faults might cause an earthquake.
Earthquakes caused by human activity do not only happen in Pohang. There were hundreds of microearthquakes in Basel, Switzerland in 2006 and 2007, when a geothermal generation plant was under construction. Not only geothermal power generation, but also shale gas or crude oil drilling can cause an earthquakes in a similar way. It is clear that human beings depend heavily on natural resources to generate electricity, so the downside is also experienced by human being.