Mapping Submarine Geomorphology of the Philippine and Mariana Trenches By an Automated Approach Using GMT Scripts

This paper presents a geospatial analysis of two oceanic trenches using a GMT (Generic Mapping Tools) cartographic method that exploits the scripting approach to visualisation of their geometric shapes. To this end, the research applies the high-resolution datasets GEBCO and ETOPO1 and ETOPO5 for modelling of the submarine relief. This allows taking into account the 2D and 3D shape deviations in the geomorphology of the two selected segments of the trenches by transecting a series of the cross-section profiles. A scripting algorithm of spatial data processing based on the GMT techniques visualised the topography of the submarine objects in 2D and 3D forms and extracted the topographic data from raster grids for statistical analysis of depth using the cross-section transect profiles of both trenches. The bathymetry of the Mariana Trench was evaluated in the southern segment located near the Challenger Deep area, southwest of Guam Island, in comparison with the segment of the Philippine Trench, which was transected in the surroundings of Mindanao Island. The study presented a comparative submarine geomorphic modelling and spatial analysis of the Philippine Sea basin area. The bathymetric analysis of the relief in the Mariana and Philippine trenches showed effective performance of the GMT scripting toolset in advanced cartographic data analysis and visualisation.