Tectonic Processes and Seismic Activity in the Korean Peninsula

The Korean Peninsula lies within a stable intraplate region yet exhibits a complex network of faults inherited from Mesozoic and Cenozoic events. Strain accumulates at low rates, driven by far-field interactions between the Pacific, Philippine Sea and Eurasian plates and by neotectonic processes in the East Sea back-arc. Major structures such as the Yangsan, Ulsan and Chugaryeong faults accommodate dextral and reverse strike-slip motion, with rupture behaviour modulated by fault geometry, lithology and depth-dependent stress fields. Although earthquakes in this region are moderate in magnitude, historical records and modern GPS measurements reveal episodic moderate events (ML 5.0–5.5) and associated ground deformation, including liquefaction and slope failures. Recent moderate shocks have perturbed the crustal stress state, increasing seismic hazard in densely populated areas. Advances in geodetic monitoring, high-resolution imaging and palaeoseismology have improved understanding of fault segmentation, rupture termination and the role of fault intersections. This body of work carries global significance for risk assessment in slowly deforming continental interiors.

Research from Nature Portfolio

Recent studies have shown that palaeoearthquake ruptures on the Yangsan Fault often terminate below the surface in unconsolidated sediments, controlled by inherited fault geometry, depth-dependent stress transitions and low cohesion in near-surface deposits. Multi-scale structural analysis revealed that rupture splays bifurcate where basement faults are unfavourably oriented, illuminating mechanisms of upward rupture arrest and distributed deformation. Other investigations demonstrate that the 2011 Tohoku-Oki megathrust earthquake induced stress perturbations across the peninsula, accelerating the occurrence of ML 5-level events. The rate of moderate shocks increased four-fold post-2011, leading to complex stress interactions and elevated seismic risk that may persist until crustal properties recover.

Tectonic Processes and Seismic Activity in the Korean Peninsula publication trend

The graph below shows the total number of articles in tectonic processes and seismic activity in the korean peninsula across all publications each year (not limited to Nature Index journals).

Technical terms

Intraplate seismicity: Earthquake activity occurring within the interior of a tectonic plate rather than at plate boundaries.

Strike-slip rupture: Horizontal displacement along a fault plane where two blocks move laterally past each other.

Fault scarp: A step or offset on the ground surface where one side of a fault has moved vertically relative to the other.

Liquefaction: Process by which water-saturated unconsolidated sediments temporarily lose strength and stiffness during seismic shaking.

Digital elevation model (DEM): A three-dimensional representation of a terrain’s surface generated from geospatial elevation data.

References

1. Geospatial data-driven assessment of earthquake-induced liquefaction impact mapping using classifier and cluster ensembles. Applied Soft Computing (2023).
2. Near-surface termination of upward-propagating strike-slip ruptures on the Yangsan Fault, Korea. Scientific Reports (2023).
3. Time-advanced occurrence of moderate-size earthquakes in a stable intraplate region after a megathrust earthquake and their seismic properties. Scientific Reports (2018).
4. Strain accumulation in South Korea inferred from GPS measurements. Earth, Planets and Space (2006).
5. Active tectonics, earthquakes and palaeoseismicity in slowly deforming continents. Geological Society London Special Publications (2016).
6. Transition from buckling to subduction on strike-slip continental margins: Evidence from the East Sea (Japan Sea). Geology (2018).
7. Fault intersections control short period intraplate start-stop seismicity in the Korean Peninsula. Tectonophysics (2022).
8. Active Fault Trace Identification Using a LiDAR High-Resolution DEM: A Case Study of the Central Yangsan Fault, Korea. Remote Sensing (2022).
9. Correlation of paleoearthquake records at multiple sites along the southern Yangsan Fault, Korea: Insights into rupture scenarios of intraplate strike-slip earthquakes. Tectonophysics (2023).