Crustal?Scale Fault Systems in the Korean Peninsula Unraveled by Reflection Seismic Data

An approximately 40-km long high-resolution reflection seismic profile (P3) was acquired in the metropolitan area of Seoul South Korea for purpose fault system imaging a highly noisy and challenging urban environment. Two 12t vibrators (mini-vibs) were used as source. Data recorded using dual element spread; 20 m spaced 421 wireless recorders connected to 10 Hz geophones micro-electro-mechanical-based landstreamer sensors (2 sensor spacing) attached one vibrators. The spread employed delineate both near-surface deep structures. processing results show good quality work complemented by different analysis further constraints geological interpretation. survey provide evidence 3D geometry three systems, including Chugaryeong, Pocheon, Wangsukcheon faults. A gently westerly dipping set reflectivity underlying dome-shaped package is interpreted fault, could project known surface position Pocheon fault. folded faulted dyke or sill systems. Downward continuation intersects sub-vertical Chugaryeong zone where current seismicity observed, suggesting that these two major systems may have jointly evolved form splay Reflections from are also present data dip 60° east, an opposite direction other