North Korean Nuclear Tests Linked to Surge in Earthquakes: South Korean Meteorological Agency Report

38% increase from the previous year·50% increase from the annual average number
Fourth highest frequency since KMA started an observation
Continuous earthquakes in the East Sea were due to nuclear tests in Kilju, North Korea

Last year, earthquakes of magnitude 2.0 or higher occurred more than 50% more frequently than in previous years in the Korean Peninsula and neighboring water.

According to the 2023 Earthquake Yearbook released by the Meteorological Agency on the 19th, 106 earthquakes of 2.0 or higher occurred in the Korean Peninsula and neighboring water last year. This is approximately a 50% (35 times) increase from the annual average number of occurrences (70.8 times) since the introduction of the digital seismometer in 1999. Even compared to the previous year, 2022 (77 times), it increased by 38% (29 times).

The Meteorological Agency explained that the number of occurrences in 2023 was the fourth highest since earthquake instrumentation began in Korea in 1978, following 2016, 2017, and 2018. The top three spots are periods when aftershocks frequently occurred due to the largest earthquakes in Korea, such as the Gyeongju earthquake (2016, magnitude 5.8) and the Pohang earthquake (2017, magnitude 5.4). After these two earthquakes, the number of earthquakes gradually decreased as the aftershocks subsided, but last year, it turned to an increase.

In addition, last year, there were 16 earthquakes of magnitude 3.0 or higher and 19 earthquakes that people directly felt, surpassing both the annual average and the figures from the previous year. According to previous statistics, for a magnitude 3.0 or higher, there were 10.4 earthquakes in an average year and 8 in 2022, and the number of felt earthquakes was an average of 16.5 times and 13 times in 2022.

This is interpreted as being due to continuous earthquakes in the East Sea for six months between April and October last year and frequent earthquakes due to the weakening of the ground due to nuclear tests in Kilju, North Hamgyong Province, North Korea. In May last year, a magnitude 4.5 earthquake, the largest of the year, and 16 foreshocks and aftershocks occurred in the sea near Donghae City, Gangwon Province.