Raw 2-D multi-channel seismic shot gathers (SEG-D) collected at the Chain transform fault during the 2018 ILAB-SPARC cruise

The data consists of two seismic profiles totalling 112 km collected during the ILAB-SPARC cruise aboard R/V Pourquoi Pas? from July to October 2018 at the eastern ridge-transform intersection of the Chain transform fault in the equatorial Atlantic Ocean. The profiles sample an 80-km long transform-parallel median ridge. During the survey, shots at 10 m depth were fired at a regular distance interval of 75 m and the pressure returns were recorded with a 6 km-long streamer towed at a depth of 15 m behind the ship containing 960 hydrophones at a group interval of 6.25 m. This geometry provided 40-fold seismic coverage with a common midpoint (CMP) interval of 3.125 m. Record length was 11 seconds and the sample rate was 2 ms. The source consisted of 16 airguns representing a total volume of 4990 cubic inches at 140 bars. Depth sensors and hydrophones were placed on the source array, enabling a control on depth and an estimation of the near-field source signature in real time during the acquisition. Additional details about the seismic data acquisition may be found in the accompanying cruise report. The two profiles are: (1) 37 km-long ILAB-SP08 collected from North to South containing 491 shots and (2) A 75-km long section of a 147 km-long profile ILAB-SP05 containing 1000 shots. The raw 2-D MCS shot gathers are in SEG-D format, bundled as TAR files, one for each profile. The data was generated as part of the project called Imaging Lithosphere Asthenosphere Boundary–St. Paul, Romanche and Chain (ILAB-SPARC). The ILAB-SPARC cruise was funded by the European Research Council Advanced grant no. 339442 TransAtlanticILAB awarded to Dr. Satish Singh.