A high-resolution seismic reflection study in the Yangsan fault zone near Geongju, Korea

Abstract

Recent earthquakes near nuclear power plants in Korea have triggered public concerns about possible seismicity of the Yangsan fault zone in the southeastern part of the Korean peninsula. To reveal subsurface structures of this fault zone, high-resolution common- midpoint seismic reflection profiling was carried out near Gyeongju, Korea. The east bounding fault of the graben appears to be reactivated at least once after the formation of the graben. Some faults displacing the shallowest reflector within the overburden and depression of ground surface by 0.44 m above the central part of the graben may indicate that the Yangsan fault is active.