Ocean Bottom Seismometer data of line OBS2017-2 in the South China Sea

This archive includes wide-angle seismic data from line OBS2017-2 collected in the South China Sea. Dataset line OBS2017-2 was collected in June 2017, using R/V “Shiyan 2” that belongs to the South China Sea Institute of Oceanology, CAS. The objective is to investigate the crustal structure of the Zhongsha Block and to characterize the architecture of the continent-ocean transition zone of the mid-northern South China Sea. The spacing of short period Ocean-Bottom-Seismometers (OBSs) was ~9.6 km. Thirty-seven 4-component short-period (4.5–100 Hz) OBSs and three long-period (0.03–50 Hz) OBSs (LOBSs) were deployed along a 400-km-long roughly N-S trending profile, spanning the Northwest Sub-basin, Zhongsha Trough, Zhongsha Atoll, and Southwest Sub-basin from north to south. Three instruments (OBS21, LOBS01, LOBS03) could not be recovered, and one instrument (OBS13) did not provide usable data for geophysical interpretation. The remaining thirty-five short-period OBSs and one LOBS are available for geophysical data analysis, providing record sections of excellent quality. The sample rates were 4 ms, 10 ms, and 20 ms for the different instruments. The seismic source consisted of an array of four BOLT air-guns with a total volume of 6,000 cubic inches and was towed at ~10 m depth below sea level. 1,767 shots had been fired along OBS2017-2 from south to north, and the shooting intervals were set at 80-110 s with a nominal ship speed of ~4.5 knots, resulting in a shooting interval of ~200 m on average. The format of seismic data in this repository is SEGY.