Anchor: A team of South Korean and overseas experts who carried out a year-long investigation into the exact cause of the country's second-largest-ever earthquake in Pohang two years ago has announced its findings. Seoul National University Professor Lee Kang-kun who led the study said his team concluded that the quake in Pohang was "triggered" and not "natural."
Our Choi You Sun reports.

Report: 

[Nat sound: Joint Team Announcement on Cause of Pohang Earthquake (Mar. 20)]

The five-point-four magnitude earthquake that struck South Korea's southeastern city of Pohang in 2017 was the second-largest earthquake recorded in South Korea's modern history and injured dozens of people and damaged over two-thousand homes.

Based on their year-long investigation, a government-led team of local and overseas experts announced on Wednesday that the November 15th quake was most likely triggered by a nearby experimental geothermal power plant. 

[Sound bite: Shemin Ge, University of Colorado Professor] 
"We have reached the conclusion that the Pohang earthquake was triggered by the EGS(enhanced geothermal system) stimulation and the seismicity induced by the injection, which activated a previously unmapped fault zone, which in turn triggered the main shock."

Professor Shemin Ge from the University of Colorado Boulder, who co-headed the joint team's probe, said the high-pressure water injected into one of the nearby pits vitalized an unknown fault zone, thereby triggering the quake.

[Sound bite: Shemin Ge, University of Colorado Professor] 
"Soon after the earthquake, the questioning rose about the possible involvement in the earthquake of Korea's first Enhanced Geothermal System(EGS) and because the epicenter is located near the EGS."

Geothermal power generation usually involves injecting water several kilometers deep underground, heating up the water with terrestrial thermal energy, and then using the steam to run turbines. 

With many Pohang residents seeking compensation the government said it will permanently suspend the geothermal power plant. 

The energy ministry will also carry out a thorough inspection in the process of pursuing its project to commercialize geothermal power plants and to select suitable sites to house such plants. 

In addition, the energy ministry said that starting from this year, it will spend nearly 226 billion won over the next five years to repair houses and infrastructure in the town of Heunghae in Pohang, which suffered the biggest blow from the 2017 quake.
Choi You Sun, KBS World Radio News.