13 Aftershocks Occur in Jeju... Windows Broken and Cracks in Walls Reported

Aftershock Magnitude 1.3~1.7, KMA "Will Continue for Several Months"
Reports of Damage Including Wall Cracks and Tile Cracks/Deformations Received
11th Largest Earthquake Recorded Domestically

On the 14th, immediately after a magnitude 4.9 earthquake occurred 41 km southwest of Seogwipo, Jeju, the Korea Meteorological Administration's National Earthquake and Volcano Situation Room responded.

Since a magnitude 4.9 earthquake occurred in Seogwipo, Jeju, the previous afternoon, 13 aftershocks have taken place.

On the 15th, the Ministry of the Interior and Safety announced that since the earthquake occurred 41 km southwest off the coast of Seogwipo City, Jeju, 13 aftershocks had been recorded as of 6 a.m. that day. The aftershocks ranged in magnitude from 1.3 to 1.7. During the 2017 Pohang earthquake, about 100 aftershocks ranging from magnitude 2.2 to 4.3 occurred. The Korea Meteorological Administration explained, "Aftershocks can continue for several months up to a year."

In Jeju, four damage reports were received. Windows were broken, cracks appeared on walls, and tile cracks and deformations occurred. However, no abnormalities were found in nuclear power plants, electricity, or communications. As of 5:30 a.m. that day, a total of 173 reports were received from people who felt the earthquake. At the Korea Meteorological Administration's Typhoon Center in Jeju, buildings shook for about two seconds accompanied by a "thud" sound, and buildings also shook at the Jeju office and Seogwipo observation station. Near Daejeong-eup in Seogwipo, the earthquake was strong enough to cause a commotion as hotel guests nearby evacuated.

On the afternoon of the 14th, Jeon Hae-cheol, Minister of the Ministry of the Interior and Safety, chaired an emergency video conference with related agencies including the Fire Agency, the Korea Meteorological Administration, and Jeju Province regarding the earthquake in Seogwipo City, Jeju Island, at the Seoul Situation Center of the Central Disaster and Safety Countermeasures Headquarters in the Government Seoul Office Building, Jongno-gu, Seoul, and checked the damage situation and the response status of each agency.

The Ministry of the Interior and Safety issued an earthquake crisis alert at the "Warning" level and activated Level 1 emergency operations at the Central Disaster and Safety Countermeasures Headquarters. A field situation manager was urgently dispatched to Jeju to inspect the earthquake site. Inspection results confirmed no abnormalities at power plants, radioactive waste disposal sites, Jeju Airport runways and facilities, reservoirs, dams, or water supply and sewage facilities. All 198 schools in Jeju operated normally without adjusting academic schedules. Local governments checked the safety and departure/return status of home-treated and self-quarantined individuals.

This earthquake ranks as the 11th largest domestic earthquake ever recorded and is the largest earthquake to occur this year. Since seismic observations began, the largest earthquake was a magnitude 5.8 event that occurred 8.7 km south-southwest of Gyeongju City, Gyeongbuk, in September 2016, and the second largest was a magnitude 5.4 earthquake that occurred 8 km north of Buk-gu, Pohang City, Gyeongbuk, on November 15, 2017.

The Korea Meteorological Administration stated there is no possibility of a tsunami. Yu Sang-jin, head of the Earthquake and Volcano Policy Division at the Korea Meteorological Administration, said, "This earthquake was caused by strike-slip fault movement, so it does not have enough energy to generate a tsunami. Tsunamis become a risk when a certain level of energy is released by reverse or normal faulting."

Regarding volcanic activity or connections to recent earthquakes in Japan, Director Yu said, "Further research or investigation is needed," but added, "Earthquakes occur as stress accumulates and is released, so they can be directly or indirectly influenced by nearby earthquakes."

This earthquake occurred offshore, so compared to the Pohang earthquake, the damage is relatively minor. Earthquake damage is assessed by "seismic intensity," with instrumental intensities of 5 in Jeju and 3 in Jeonnam. An instrumental intensity of 5 means almost everyone feels the shaking, dishes and windows may break, and unstable objects may fall over.

This content was produced with the assistance of AI translation services.