Raw seafloor magnetotelluric, CSEM, and seismic data acquired over the Goban Spur, during James Cook cruise JC251 (2023)

These raw seafloor electric and magnetic field time series data files were acquired on RRS James Cook cruise JC251 in 2023 during a joint magnetotelluric, controlled-source EM, and active source seismic experiment near the Goban Spur (https://marineemlab.ucsd.edu/Projects/Goban/) in the northeastern Atlantic Ocean. They were collected using 34 SIO Mk III OBEM seafloor magnetotelluric/electromagnetic sensors navigated with LBL acoustics. The data files are in the Scripps EM data logger binary format with Ch1 = magnetometer coil, instrument N, Ch2 = magnetometer E, Ch3 = electric field N, Ch4 = electric field E, Ch5 = seismic hydrophone. The instruments, data format, and playback software are described at https://marineemlab.ucsd.edu/instruments/. The data set was generated as part of the joint NSF GEO-NERC project called Quantifying evolution of magmatism and serpentinisation during the onset of seafloor spreading. Funding was from NSF award OCE-2026866 and from the UK Natural Environment Research Council grants NE/T007419/1 and NE/T007192/1).