Three-dimensional four-component ocean bottom seismometer dataset acquired from an active fluid flow structure: Scanner pockmark, North Sea in 2017

The three-dimensional wide-angle active source seismic dataset was acquired during the CHIMNEY seagoing expedition (RRS James Cook – JC152 experiment; August – September 2017), at the Scanner pockmark, an active fluid flow structure in the North Sea. The aim of the data collection was to understand the structure and the physical properties below this methane-venting seafloor depression. The data were acquired using two GI-guns in harmonic mode (2x210 cu. in.) and 25 four-component Ocean Bottom Seismometers recording at a sampling rate of 4 kHz. The shooting interval was 8 s, equivalent to 18.5 m at the mean vessel speed of 4.5 kn. Additional seismic reflection data acquired during JC152 are used for comparison with the ocean bottom seismometer data. Three sub-bottom profiler profiles, one horizon surface (Base of the Witch Ground formation) and one multi-channel profile acquired with a surface sparker are used for comparison. The sub-bottom profiler data were acquired using a chirp sweep lasting 0.035 s, with a bandwidth of 2.8-6 kHz, and a central frequency of 4.4 kHz. These profiles have a trace spacing of 2.5 m and a vertical resolution of < 15 cm. The base of the Witch Ground formation is interpreted as a surface from over 100 SBP profiles and the surface attributes are used for comparison with OBS recordings. The Squid surface sparker data were acquired with a 80-1800 Hz source and 2 s shot interval (~4.6 m at 4.5 kn), and were recorded on a multi-channel streamer