Fig. 2
a Track of a sea-surface platform of the observational data obtained at G20 on November 13, 2015 is shown by the cross symbols. The color represents the observational time. Gray triangles show the seafloor transponder positions. b Time series of the sea-surface platform positions shown in (a). c Estimated horizontal array displacements for individual acoustic shot groups using the observational data of a, b. The color represents the observational time. d Time series of the estimated horizontal array displacements and NTDs corresponding to the results of (c)