STRATIGRAPHIC ANALYSIS AND GEOACOUSTIC MODEL AT THE YSDP-105 LONG-CORE SITE IN THE MID-EASTERN YELLOW SEA

In the mid-eastern part of the Yellow Sea, glacio-eustatic sea-level fluctuations and a regional tectonic subsidence have combined to represent an aggradational stacking pattern of sedimentary units during late Pleistocene-Holocene. The accumulated sediments are divisible into two-type units of Type-A and Type-B in high-resolution air-gun seismic profiles and a long core of 64 m at the YSDP-105 site. Type-A unit largely comprises clast-rich coarse-grained sediments of non-marine to paralic origin, whereas Type-B unit consists mostly of tidal fine-grained sediments. Based on the stratigraphic, core, and geoacoustic analyses, this study suggested a geoacoustic model of multi-layers at the YSDP-105, deep-drilled site of the mid-eastern Yellow Sea. The geoacoustic model of 64-m depth below the seafloor with four-layer geoacoustic units was reconstructed in continental shelf strata of 45 m in water depth. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the seafloor using the Hamilton modeling method. We suggest that the geoacoustic model will be used for geoacoustic and underwater acoustic experiments of mid-frequency reflecting on the deep bottom layers in the mid-eastern Yellow Sea.

Keywords: geoacoustic model, long core, YSDP-105, Yellow Sea

Acknowledgements: This work was supported by the Agency of Defense Development grant (UD170014DD) and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2019R1F1A1057715).