Annals of Valahia University of Targoviste. Geographical Series (2019), 19(2): 73-94 DOI: 10.2478/avutgs-2019-0008 ISSN (Print): 2393-1485, ISSN (Online): 2393-1493 © Copyright by Department of Geography. Valahia University of Targoviste GEOPHYSICAL MODELLING OF THE MIDDLE AMERICA TRENCH USING GMT Polina LEMENKOVA Ocean University of China, College of Marine Geo-sciences. 238 Songling Rd. Laoshan, 266100, Qingdao, Shandong, PRC. Tel.: +86-1768-554-1605. email:
[email protected] Abstract The study is focused on the geomorphological analysis of the Guatemala Trench, East Pacific Ocean. Research goal is to find geometric variations in western and eastern flanks of the trench and correlation of the submarine geomorphology with geologic settings and seismicity through numerical and graphical modelling. Methods include GMT based analysis of the bathymetry, geomorphic shape and surface trends in topography and gravity grids. Dataset contains raster grids on bathymetry, gravity, geoid and geological layers. Technical workflow is following: 1) Bathymetric mapping by modules ('grdcut', 'grdimage'); 2) Datasets visualizing and analysis, 3) Topographic and gravimetric surface modelling by ASCII data; 4) Cartographic mapping ('psbasemap', 'psxy', 'grdcontour') 4) 3D-mesh modelling; 5) Automatically digitized orthogonal cross-stacked profiles (‘grdtrack’); 6) Visualizing curvature trends (‘trend1d’); 7) statistical histograms. Results reveal unevenness in the structure of the submarine landforms. Modelling cross-section profiles highlighted depth variation at different parts of the transects and seafloor segments. Geomorphic structure has straight shape form of the slopes with steep oceanward forearc. Its geometry has steep and strait shape which correlates with seismicity. Depth samples vary: -3000 to -6200 m, seafloor is 3-5 km wide.