Three-dimensional electrical conductivity of the world ocean and seabed sediments: effect on EM induction responses

This work presents global 3-D electrical conductivity atlas of the world ocean and seabed sediments. Ocean salinity and temperature data were converted to electrical conductivity by solving a thermodynamic equation of state of seawater. A sediment compaction model was used to estimate the depth-dependent electrical conductivity of the seabed sediments. Electromagnetic responses in a wide period band, including typical ranges used in CSEM, MT and Global studies, are significantly affected by varying ocean and sediments conductivity. Incorporating this information in a model prior to inversion helps avoid artifacts and improve data fit. The atlas is openly available along with a concise and easy to use Python toolbox.