A New 1′ × 1′ Global Seafloor Topography Model Predicted from Satellite Altimetric Vertical Gravity Gradient Anomaly and Ship Soundings BATVGG2021

In this paper, we construct a new 1′ × 1′ global seafloor topography model, BATVGG2021, using the satellite altimetric vertical gravity gradient anomaly model (VGG), SIO curv₃0. 1. nc, and ship soundings. Approximately 74. 66 million single-beam depths and more than 180 GB of multibeam grids were downloaded and adopted from the National Centers for Environmental Information (NCEI), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), and Geosciences Australia (GA). The SIO curv₃0. 1. nc model was used to predict seafloor topography at 15~160 km wavelengths, and ship soundings were used to calibrate topography to VGG ratios. The accuracy of the new BATVGG2021 model was assessed by comparing it with ship soundings and existing models. The results indicate that the standard deviation of differences between the predicted model and ship soundings is about 40~80 m, and ~93% of the differences are within 100 m, similar to that of the SIO topo₂0. 1. nc model. The new BATVGG2021 model shows better accuracy than the DTU18BAT, ETOPO1, and GEBCO₀8 models, and has been improved significantly from our last model, BATVGG2014.