Man-induced earthquakesGeothermal plant caused South Korea’ 2017 tremor

Published 20 March 2019

A rare earthquake in South Korea was triggered by the country’s first experimental geothermal power plant, government officials said Wednesday. The southeastern port city of Pohang was rattled by a 5.4-magnitude earthquake in November 2017— the second-most powerful tremor ever in the normally seismically stable South.

A rare earthquake in South Korea was triggered by the country’s first experimental geothermal power plant, government officials said Wednesday.

The southeastern port city of Pohang was rattled by a 5.4-magnitude earthquake in November 2017— the second-most powerful tremor ever in the normally seismically stable South.

Dozens of people were injured and more than 1,500 left homeless. The nationwide college entrance exam was postponed.

Japan Times reports that a year-long government-commissioned study pointed to the geothermal power plant as the cause.

The plant works by injecting high-pressure water deep underground to tap heat from the Earth’s crust, but the process had produced micro-sized seismic activity as a result, said Lee Kang-kun, who led the research.

And as time passed, this triggered the earthquake in Pohang,” he added. “We concluded that the Pohang earthquake was a ‘triggered quake’. It wasn’t a natural earthquake.”

Pohang residents filed a lawsuit against the government after the quake, and following the assessment Seoul expressed its “deep regret.”

The geothermal plant — which was temporarily suspended during the study — will be “permanently shuttered,” the trade, industry and energy ministry said in a statement.

It cost around $71 million to build the plant and test operations, which began in 2016.

Unlike neighboring Japan, the Korean peninsula rarely experiences significant quakes but seismic activity is closely monitored as part of a broader effort to detect North Korean nuclear tests.

South Korea’s most powerful quake to date was a 5.8-magnitude tremor that struck Gyeongju, also in the southeast, in September 2016.