Ocean Bottom Seismometer data of a three-dimensional seismic survey in the northern South China Sea distal margin

This archive includes three-dimensional (3D) wide-angle seismic data from a network of 49 OBSs and 11 air-gun shooting lines in the northern South China Sea distal margin drilled by the IODP Expeditions 367/368/368X. Dataset was collected during May to July 2018, using R/V “Shiyan 2” that belongs to the South China Sea Institute of Oceanology, Chinese Academy of Sciences. The objective is to investigate the 3D deep crustal structure and to reveal the rift-to-drift process in the northern South China Sea distal margin. Fifty-two 4-component short-period (4.5-100 Hz) OBSs developed by the Institute of Geology and Geophysics, Chinese Academy of Sciences were deployed with instrument spacing varying from 7 to 10 km, covering a surface of ~30000 km2. The sampling rates were 4 ms and 10 ms for different instruments. The seismic source array with a total volume of 6000 in3 (98.32 L) was composed by four Bolt air-guns towed at a depth of ~10 m. The shooting interval was 90 s at a speed of ~4.5 knots, providing a seismic trace spacing of ~200 m. A total of 8,751 shots were fired along 11 shooting lines with a total length of ~1750 km. Forty-nine OBSs were finally recovered with effective recording data. The format of seismic data in this repository is SEGY recorded by the geophone vertical component. Meanwhile, the location file of OBS stations and the navigation file of shots have also been submitted in this repository.