4.8-magnitude earthquake near Buan marks Korea's biggest quake of the year

Social Affairs

Published: 12 Jun. 2024, 09:18 Updated: 12 Jun. 2024, 18:46

4.8-magnitude earthquake near Buan marks Korea's biggest quake of the year

The epicenter of a 4.8-magnitude earthquake four kilometers outside Buan, North Jeolla, is shown on this map provided by the Korea Meteorological Administration. [NEWS1]

A 4.8-magnitude earthquake struck four kilometers (2.5 miles) outside of Buan, North Jeolla, on Wednesday morning, the Korea Meteorological Administration (KMA) announced.

Wednesday's tremor was the largest on the Korean Peninsula and surrounding area so far this year. It was also the first time in over a year that an earthquake over 4.5 magnitude occurred near Korea, since an earthquake that struck 52 kilometers off the coast of Donghae, Gangwon, on May 15 last year.

An emergency earthquake alert was issued by text message at 8:27 a.m.

The KMA initially estimated the earthquake's magnitude to be 4.7 but adjusted it to 4.8 after additional analysis.

Students at a high school near Buan gather outside the school building as emergency warnings were issued after the earthquake. [JEONBUK STATE OFFICE OF EDUCATION]

More than 290 reports of vibrations from the first earthquake were received across the country as of noon Wednesday. Most reports came from the Jeolla and Chungcheong areas, but reports also came from the Gyeonggi area and seven from Seoul.

No casualties or injuries were immediately reported. However, a warehouse wall in Buan was left cracked, and the window of a residence in Haseo-myeon near Buan was damaged. Additional property damage reports in North Jeolla included a crack in the floor of an underground parking lot in a guest house near Buan and an outdoor wall in Iksan left leaning sideways.

Some school facilities in Buan were further damaged, with the ceiling structure of a cafeteria in an elementary school falling and a room in a middle school destroyed.

A wall in a warehouse Boan-myeon near Buan is showing cracks after a 4.8-magnitude earthquake hit Wednesday. [YONHAP]

"It has been confirmed that there were no casualties from the earthquake so far," an official from the North Jeolla Fire Department said Wednesday morning. "We are maintaining readiness to respond immediately to prepare for possible emergencies."

Citizens on their commute to work on Wednesday were left shaken as the earthquake hit, with many expressing surprise and anxiety on social media.

One post on X, formerly Twitter, read, "I thought there had been an explosion," while another said, "The whole building shook, and I have never felt anything like this before."

Four schools closed on Wednesday, and several opted to resume classes online.

An employee at the Buan Celadon Museum clears an exhibition space of debris after the earthquake on Wednesday. [NEWS1]

Wednesday's earthquake was also the 16th strongest earthquake nationwide based on instrumental observations and the 12th strongest since 1999 when digital observations began.

The earthquake's epicenter was 35.70 degrees north latitude and 126.71 degrees east longitude in Jingdong-ri, Haengan-myeon, Buan. Its depth was estimated to be eight kilometers.

President Yoon Suk Yeol, currently on a trip to Kazakhstan, was briefed on the earthquake and ordered related ministries to "quickly identify the damage to national infrastructure and take all necessary measures, including conducting safety inspections."

Prime Minister Han Duck-soo also issued an emergency response order to relevant ministries regarding the earthquake.

Fallen tiles are seen near Gyehwa-myeon, Buan, after a 4.8-magnitude earthquake hit Wednesday. [NEWS1]

Han ordered the Ministry of the Interior and Safety to manage the overall situation thoroughly, inform residents of action plans so they can quickly evacuate when signs of danger are detected in preparation for additional aftershocks, and comprehensively inspect and prepare for the operating status of forecast and warning facilities.

Additionally, the Trade Ministry, the Science Ministry and the Land Ministry were asked to inspect national infrastructure such as nuclear power plants, electricity, communications and transportation to ensure no disruptions occur and to take thorough emergency preparedness measures in an emergency.

The KMA announced that Wednesday's earthquake was caused by a "strike-slip fault" movement, in which a fault moves horizontally.

The problem is that knowing which fault caused the earthquake is difficult due to a lack of information on the faults of the Jeolla region.

Experts warned that an earthquake of up to magnitude 7 could occur anywhere on the Korean Peninsula.

Until now, the Honam region reportedly had the most stable geological structure on the relatively earthquake-free Korean Peninsula, so fault investigations are lacking.

"The ground motion, or ground shaking, observed near the earthquake that occurred was about 0.15g (about 15 percent of the acceleration of gravity), and considering that the seismic design standard for nuclear power plants is 0.3g, it was a fairly large vibration," said Hong Tae-kyung, a professor in the Department of Earth System Sciences at Yonsei University.

"An earthquake of about 4.8 magnitude can occur anywhere in Korea, and especially large earthquakes can occur even in the Seoul metropolitan area where there are faults," said Kim Young-seok, a professor of geology at Pukyong National University. "Geological research and preparation are urgently needed."

BY LIM JEONG-WON, JEONG EUN-HYE [lim.jeongwon@joongang.co.kr]