A magnitude 4.8 earthquake struck near Buan, North Jeolla Province, shaking the entire region on the morning of June 12. The quake was the strongest detected in South Korea this year and the first time an earthquake with a magnitude of 4.0 or higher jolted the country’s southwestern region.
The earthquake that struck at 8:26 a.m. had an estimated depth of 8 kilometers and was followed by 17 aftershocks in the 10 hours after the main quake, according to the Korea Meteorological Administration. While the Buan area has experienced 40 earthquakes since 1978, none have previously exceeded a magnitude of 4.0. This is also the first time an earthquake with a magnitude of 4.0 or higher has occurred inland in the broader Honam region rather than offshore.
The quake’s epicenter was near the Buan Public Stadium, just 4 kilometers south-southwest of the Buan County Office, striking in the heart of the city. Typically, earthquakes that hit inland on the Korean Peninsula have a depth of about 10 kilometers, but this quake was shallower at 8 kilometers, intensifying the shaking as the fault twisted.
The Modified Mercalli intensity scale, which measures the amount of shaking and extent of earthquake damage at a particular location, recorded a magnitude of 5 in North Jeolla Province, where Buan is located. An intensity of 5 indicates that everyone feels the earthquake and that windows, dishes, and other items may break. Strong tremors were also felt in the Yeongnam and Chungcheong provinces, with magnitudes of 3 to 4. Reports of feeling the ground shaking came from all over the country, including the Seoul metropolitan area and Gangwon Province.
Commuters described the experience as alarming, with some saying, “I thought a war had broken out” and “It felt like a bomb was exploding.” While there were no casualties, several schools in Buan County reported property damage, including falling ceiling structures in cafeterias and cracks in buildings. Four schools were closed, while three others switched to resume classes online. The Ministry of Interior and Safety raised the alert level of the Central Disaster and Safety Countermeasures Headquarters to level 1, which is the lowest in the government’s three-tier emergency alert system. An emergency earthquake alert was also issued.
Historically, major earthquakes on the Korean Peninsula have been concentrated in the Yeongnam region, close to Japanese waters in the Ring of Fire. However, with this recent earthquake of magnitude 4.0 and higher striking the Honam region, which is not part of the Ring of Fire, experts now suggest that “there is no longer an ‘earthquake safe zone’ on the Korean Peninsula.”
