Velocity structure in the South Yellow Sea basin based on first-arrival tomography of wide-angle seismic data and its geological implications

• Published in: Acta oceanologica Sinica Vol. 42; no. 2; pp. 104 - 119
• Main Authors: Zhao, Weina, Wu, Zhiqiang, Hou, Fanghui, Zhang, Xunhua, Hao, Tianyao, Kim, Hanjoon, Zheng, Yanpeng, Chen, Shanshan, Wang, Huigang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-02-2023; Springer Nature B.V; Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China%Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266071,China%Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China%Marine Active Fault Research Group,Korea Institute of Ocean Science and Technology,Busan 49111,Republic of Korea%Key Laboratory of Marine Geology and Metallogeny,First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China%School of Marine Science and Technology,Northwestern Polytechnical University,Xi'an 710072,China; Qingdao Research Institute,Northwestern Polytechnical University,Xi'an 710072,China; Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences,Wuhan 430074,China
• Subjects: Anomalies; Cenozoic; Climatology; Compression; Compressive strength; Distribution; Drilling; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Geologic depressions; Geology; Gravity data; Lithology; Magnetic data; Marine & Freshwater Sciences; Marine sediments; Mesozoic; Multilayers; Ocean bottom; Ocean floor; Oceanic crust; Oceanography; Oceans; Palaeogene; Palaeozoic; Paleogene; Paleozoic; Sediment; Sediments; Seismic activity; Seismic analysis; Seismic data; Seismic profiles; Seismic tomography; Seismographs; Seismological data; Tectonics; Thickness; Tomography; Uplift; Velocity; Vertical velocities; Yellow Sea; strata velocity structure; ocean bottom seismograph; South Yellow Sea basin; wide-angle seismic data; CSDP-2
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-022-2028-y

The South Yellow Sea basin is filled with Mesozoic-Cenozoic continental sediments overlying pre-Palaeozoic and Mesozoic-Palaeozoic marine sediments. Conventional multi-channel seismic data cannot describe the velocity structure of the marine residual basin in detail, leading to the lack of a deeper understanding of the distribution and lithology owing to strong energy shielding on the top interface of marine sediments. In this study, we present seismic tomography data from ocean bottom seismographs that describe the NEE-trending velocity distributions of the basin. The results indicate that strong velocity variations occur at shallow crustal levels. Horizontal velocity bodies show good correlation with surface geological features, and multi-layer features exist in the vertical velocity framework (depth: 0–10 km). The analyses of the velocity model, gravity data, magnetic data, multichannel seismic profiles, and drilling data showed that high-velocity anomalies (>6.5 km/s) of small (thickness: 1–2 km) and large (thickness: >5 km) scales were caused by igneous complexes in the multi-layer structure, which were active during the Palaeogene. Possible locations of good Mesozoic and Palaeozoic marine strata are limited to the Central Uplift and the western part of the Northern Depression along the wide-angle ocean bottom seismograph array. Following the Indosinian movement, a strong compression existed in the Northern Depression during the extensional phase that caused the formation of folds in the middle of the survey line. This study is useful for reconstructing the regional tectonic evolution and delineating the distribution of the marine residual basin in the South Yellow Sea basin.