169-9 Segmentation of the Yangsan Fault System in a Slowly Deforming Region: Implications for Fault Model Development

Session: Advances and Challenges in Seismotectonic Studies in Slow-Deforming Regions

Presenting Author:

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Abstract:

The Yangsan Fault System (YFS) is the largest onshore strike-slip fault in the Korean Peninsula and is considered the most significant source of potential large earthquakes in the region. Despite the absence of historical surface-rupturing events, numerous paleoseismological and geomorphic studies demonstrate that the YFS has generated repeated large earthquakes during the late Quaternary. This study examines the segmentation and structural characteristics of the YFS in the context of seismic hazard assessment in slowly deforming tectonic environments. Fault segmentation is defined through integrated analyses of fault geometry, step-overs, and fault terminations, combined with paleoseismic trenching data and geomorphic indicators. These results suggest that the YFS is divided into multiple segments, and if paleoseismic histories are further incorporated for each segment, the proposed segmentation may be applied to developing fault models for seismic hazard assessment in slowly deforming regions lacking historical surface-rupturing earthquakes.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-11076

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