There is a great possibility that the nearby geothermal power plant caused the 5.4-magnitude earthquake in Pohang on November 15, 2017. This official conclusion by a government research team confirmed that a policy implemented without sufficient preparation was the reason for the second largest earthquake in the history of South Korea. The government announced it would conduct a strict investigation to see if there were any problems in the process of promoting the project.

The announcement this day is expected to have a major impact on the compensation for damage claims that the citizens of Pohang filed against the government, which promoted geothermal power.

The government research team studied the Pohang earthquake for over a year in order to analyze the relationship between the earthquake and geothermal power generation. The Geological Society of Korea oversaw the analysis. On March 20, the research team held a press conference at the Korea Press Center in Jung-gu, Seoul and released the results.

Lee Kang-kun, a professor at Seoul National University, who headed the research team said, "To generate power using geothermal energy, they drilled wells and filled them with water. In this process a series of minor earthquakes (magnitudes of less than 2.0) occurred, and as the effects accumulated, they triggered the Pohang earthquake." Shemin Ge, a professor at the University of Colorado Boulder, who took part in the overseas investigation committee, also explained that the high-pressure water injected for geothermal power generation activated an unidentified fault, triggering the earthquake.

According to the research team, 96 earthquakes occurred in the neighboring areas from January 2016, when the water was injected into the geothermal power plant, up until the Pohang earthquake in November 2017. A total of 12,800 m3of water was injected into the geothermal power plant on five occasions from January 2016 to September 2018.

The Ministry of Trade, Industry and Energy gathered a research team of South Korean and overseas experts to analyze the Pohang earthquake after academia and residents cited the geothermal power plant as the cause of the earthquake. The study was launched last March.

Geothermal power plants generate power by injecting water into the ground and heating the water with the Earth’s heat. The steam that is formed in the process is used to turn the turbine to generate power. The academia in South Korea and overseas had raised concerns claiming that the process of injecting water more than 4 kilometers below ground using high pressure would weaken the foundation. They argued that eventually stress would accumulate in the fault triggering an earthquake.

The government announced, "We will humbly accept the results of the study," and added, "We will permanently suspend the geothermal power plant project in Pohang and conduct a strict investigation on the process of commercializing geothermal power and the aptness of the site selection."