4.8 magnitude earthquake strikes Buan, strongest of year

A 4.8 magnitude earthquake struck near Buan-gun, North Jeolla Province, Wednesday morning, marking the strongest earthquake in South Korea's southwestern region's history and the most powerful quake of the year, according to the Korea Meteorological Administration.

The earthquake that occurred at 8:26 a.m. was the 16th strongest earthquake since 1973, when the country started compiling relevant records. The quake’s depth was measured at 8 kilometers and it was followed by 17 aftershocks as of 6 p.m., with the strongest aftershock measured at a magnitude of 3.1.

The aftershocks were felt in other regions, including Seoul, Incheon and Gyeonggi Province, as well as the South and North Chungcheong provinces, the South and North Gyeongsang provinces, Busan, Daegu and Ulsan.

A nationwide emergency alert was issued about nine seconds after the quake was detected.

According to the KMA, the earthquake’s strength was measured at the “moderate” level in North Jeolla Province on the Modified Mercalli intensity scale, which is the fifth highest in the 12-tier system. The fifth level, according to this scale, defines the earthquake as being felt by nearly everyone, with some dishes and windows broken.

The earthquake that hit Buan-gun was unusually strong, given that the region is located where earthquakes are rare due to the absence of seismically active fault lines, officials were quoted as saying in local reports.

There have been 28 earthquakes noted within Gwangju, North Jeolla Province and South Jeolla Province since records were first kept in 1978, with all having occurred within an 80-kilometer radius of Buan. The strongest earthquake previously measured in the region dates back to December 2015, in Iksan, North Jeolla Province, with a magnitude of 3.9.

The National Fire Agency and the KMA said they had received 309 reports nationwide related to the quake as of 10:30 a.m., mostly regarding property damage and shaking from aftershocks. Some of the property damage included cracks formed in walls, broken windows and collapsed ceilings -- mostly in schools and residential homes. According to the fire agency, no reports of casualties or injuries had been received.

Out of those 309 reports, 77 came from North Jeolla Province, where Buan-gun is located. A report was also filed as far afield as Wonju, Gangwon Province, some 300 kilometers to the northeast of Buan-gun.

“I woke up after hearing loud, banging noises by my walls around 8:28 a.m. and shortly felt my entire room shake,” Kim Ha-jin, who lives in Jeonju, 36 kilometers from Buan-gun, recalled to The Korea Herald. “My books and sheets of paper that were stacked up on my desk scattered all across the floor. It was really scary.”

According to the Ministry of Education, four schools -- including one in Buan-gun and one other each in North Chungcheong Province, South Chungcheong Province and South Jeolla Province -- closed due to the earthquake. Three schools in the Chungcheong provinces and North Jeolla Province adjusted their school hours, while another school in North Jeolla Province switched to online classes for the day.

No damage has been reported at any of the nuclear or hydroelectric plants across the nation and all are operating safely, according to the Korea Hydro and Nuclear Power Co.

Following the earthquake, President Yoon Suk Yeol instructed the government to carry out a “swift damage assessment and safety check," as well as to provide swift and accurate information to the public to ensure the people “do not get anxious about possible aftershocks.”

Prime Minister Han Duck-soo also ordered the interior minister to take “thorough and effective measures” while providing safety guidelines for those in high-risk areas in the event of an aftershock. Han instructed the industry, science and land ministers to check power and communication lines to ensure no service disruptions would occur and to prepare measures in case of an emergency.

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. A separate earthquake alert was also issued at the “vigilance” level, the third-highest in the five-tier system.

Meanwhile, Wednesday’s earthquake was the first in over a year to hit Korea with a magnitude of 4.5 or greater. On May 15, 2023, a 4.5 magnitude earthquake was detected off the east coast near Gangwon Province.