Site flatfile of Korea meteorological administration’s seismic stations in Korea

This study constructed a flatfile with the information useful to satisfy the site characterization requirements of Korea Meteorological Administration’s seismic network, which was expanded significantly to 265 seismic stations following the 2016 Gyeongju Earthquake and the 2017 Pohang Earthquake in South Korea. Seismic response parameters, including the average seismic shear-wave velocity from the surface to a depth of 30 m (V_S30), the depth of the engineering bedrock (H), and the mean V_S of soils above the engineering bedrock (V_S,Soil), were collected for each seismic station using existing available data and were obtained via direct in situ tests and explorations, including borehole drillings, downhole tests (DHTs), and surface seismic tests (multichannel analysis of surface waves [MASW]). To ensure the comprehensive coverage of all observation sites, terrain- and geological-map-based proxy techniques were applied to all stations. In addition to currently operational seismic stations, data on closed stations were collected and included as much as possible to enhance the accuracy of the seismic observational data at those points. For the 265 seismic stations, 28% of the representative V_S30 values were obtained from geophysical investigations, such as DHTs and MASW, whereas 60% were collected using geotechnical in situ methods, such as boring and standard penetration tests. Twelve percent of the representative V_S30 data were estimated using seismic records or proxy-based techniques. Finally, all observation sites were classified according to three engineering site classification systems: two internationally accepted V_S30-based National Earthquake Hazards Reduction Program codes and an H- and V_S,Soil-based Korean code.