"Ten Years After the Gyeongju Earthquake"...Seeking Solutions to Korean Peninsula Seismic Hazards in Mongolian Faults

KIGAM and Mongolia's IAG launch five-year joint research
...building scientific evidence on long-period intraplate earthquakes

Ten years have passed since the magnitude 5.8 earthquake that struck Gyeongju, North Gyeongsang Province, on September 12, 2016. Researchers are now looking to faults in Mongolia for solutions to enhance the reliability of seismic hazard assessments for the Korean Peninsula. The Korea Institute of Geoscience and Mineral Resources (KIGAM) has joined forces with Mongolia, where paleoearthquake traces are well preserved, to identify the recurrence intervals of intraplate earthquakes.

The Korean Peninsula lies within the Eurasian Plate, where the recurrence interval of large earthquakes is long, and dense forest cover and urban development make it difficult to identify past earthquake traces at the surface. In contrast, Mongolia shares a similar intraplate crustal environment but, thanks to its arid climate and extensive exposed terrain, surface deformation caused by paleoearthquakes is relatively well preserved. This is why it is regarded as a "natural laboratory" where the characteristics of long-period intraplate earthquakes can be quantitatively analyzed.

In June of last year, a research team from the Active Tectonics Research Center at the Korea Institute of Geoscience and Mineral Resources (KIGAM) was conducting sampling for age dating on the Unekteu Fault in Mongolia. Provided by the Korea Institute of Geoscience and Mineral Resources (KIGAM).

On February 11, KIGAM signed a memorandum of understanding (MOU) in Ulaanbaatar, Mongolia, with the Institute of Astronomy and Geophysics (IAG) to strengthen cooperation in the field of earthquake science.

IAG is a government research institute under the Mongolian Academy of Sciences and Technology and is a key institution responsible for operating the nationwide seismic monitoring network in Mongolia, as well as conducting geological and geophysical research. The new agreement is intended to reaffirm the partnership established in 2019 and to reinforce the foundation for steadily promoting joint research on earthquakes and active faults over the next five years.

The two institutions will expand cooperation in areas such as: joint investigation and data sharing on major active faults in Mongolia; advancement of technologies for detecting and analyzing paleoearthquakes; training and development of specialists and technical training programs; and the organization of joint workshops and seminars. By combining Mongolia's extensive field data with KIGAM's high-precision analytical capabilities, they plan to identify the long-period behavior of intraplate earthquakes and build a scientific basis for seismic hazard assessment models for the Korean Peninsula.

The joint research is already producing results. In 2022, a multidisciplinary investigation was carried out on the Mogod Fault, where a magnitude 7.1 earthquake occurred in 1967, and it was determined that four strike-slip fault segments and one reverse-fault segment ruptured simultaneously. This was followed by trench investigations on the five fault segments to conduct parallel analyses of their recurrence intervals.

In 2023, at the Bulnai Fault, the team enhanced the technical completeness of reconstructing the fault activity history by adding lake and marsh sediment coring surveys to supplement existing trench investigations. Starting in 2025, they will launch investigations of the southern Omnogovi fault zone, and they plan to sequentially secure paleoearthquake information on major fault zones in East Asia, including China and Japan, in order to analyze correlations with seismic activity on the Korean Peninsula.

KIGAM is incorporating the results of paleoearthquake studies in Mongolia into its "Korean Peninsula Potential Earthquake Characterization Model" to improve the reliability of predictions of earthquake magnitudes and occurrence frequencies. By combining domestic observational data accumulated since the Gyeongju earthquake with overseas paleoearthquake data, the institute aims to support the scientific advancement of national earthquake disaster prevention policies and to help strengthen mid- to long-term earthquake preparedness systems.

Kwon Ikhyun, President of KIGAM, stated, "In intraplate earthquake research, the key is to secure accumulated international comparative data from a long-term perspective," adding, "We will continue to reinforce the scientific foundation of seismic assessments for the Korean Peninsula based on the paleoearthquake research outcomes obtained through our cooperation with Mongolia."

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