Even ancient Koreans recorded seismic activity on the peninsula
“There was an earthquake in August,” states the “Samguk Sagi” or “History of the Three Kingdoms,” the oldest historical records that still exist in Korea. This account of an earthquake in the year 2 AD is the oldest historical record of an earthquake in Korea.
Twenty-five years later, during the reign of King Onjo of Baekje in the year 27 AD, the record says, “Many people died as their houses were destroyed.”
In March of 779 AD, the book says, “Houses collapsed and people died because of an earthquake in Gyeongju.” It is estimated that the magnitude of this earthquake was between 8.0 and 9.0. The magnitude here refers to the intensity of the quake that people feel, not the Richter scale that measures the size of quakes at their origin.
The “Annals of the Joseon Dynasty,” the written record of 472 years of the Joseon Dynasty (1392-1910), has a detailed record of the regions that were hit by earthquakes.
On May 9, 1430, 100 cities in the Gyeongsang and Jeolla provinces were listed as being affected by an earthquake, making it possible to detect the origin of the seismic center, which was Hamyang in South Gyeongsang.
During the 12th year of King Sejong’s reign, there were 10 earthquakes recorded in the book. This shows how detailed the record was, considering the number far exceeds today’s average of 7.1 earthquakes that people can feel per year since 1978, when earthquake detection technology was adopted in Korea.
So far, seismologists found 1,800 incidents of earthquakes by studying various historical records in Korea.
“Earthquakes were recorded with special attention during the era of kings because people thought national disasters were closely related to the reign of kings,” said Kyung Jae-bok, a professor of earth science education at Korea National University of Education.
“Calculations to estimate the magnitude in relation to the size of an area struck by an earthquake were developed then,” he added. “It seems that the scale of strong earthquakes ranged from 6.0 to 7.0. The strongest one seems to have been in the scale of 6.5.”
In contrast, Lee Kie-hwa, an emeritus professor of geophysics at Seoul National University’s School of Earth and Environmental Sciences, estimates that there have been a total of nine earthquakes of magnitude 6.7 or above across the peninsula, in regions such as Seoul, Gyeongju, Gangneung and Hamhung.
On Oct. 7, 1978, a 5.0-magnitude earthquake struck Hongseong-eup in South Chungcheong. Two people were injured, and 2,800 houses were damaged as a result. The incident led the government to implement earthquake-detection activities.
BY KANG CHAN-SU [email@example.com]