The process and Mechanism of Ridge Jump in the South China Sea: Insights from Deep Seismic Velocity Structure

This archive includes seismic data from a wide-angle seismic survey line OBS2021-1, transecting the position of fossil mid-ocean ridge which is extinced at 25 Ma. The dataset was acquired in May of 2021, based on R/V "SHIYAN2", which belongs to the South China Sea Institute of Oceanology, Chinese Academy of Sciences. This survey focus on the deep seismics velocity structure and mechanism of ridge jump in the South China Sea. This 290 km long survey line comprises 30 four-components short-period OBS stations (sampling frequency: 100-250 Hz) deployed at 10 km intervals. 26 OBSs provide the seismic data for geophysical analysis, while three OBSs were unfortunately unrecovered and one OBS’s data is abnormal. The seismic source consisted of an array of four BOLT air guns with a total volume of 6,000 cubic inches, positioned approximately 10 m below sea level. Shots interval was 90 s with the vessel maintaining a speed of 4–5 knots. The seismic data is about P-wave phases travel-time of 26 OBSs, after necessary correction works.