Figure F1. Bathymetric map of the Izu-Bonin-Mariana region color-contoured in shaded bathymetric relief. The two boxes show the locations of Figures F2 and F3 (map constructed using Generic Mapping Tools [GMT] software [
Data Processing and Plotting Using Generic Mapping Tools (GMT) Course – EarthByte
Illustration Gallery — GMT 6.5.0 documentation
shapefile - Fill color in polygons using attribute variable in GMT (Generic Mapping Tool) - Geographic Information Systems Stack Exchange