Geomorphological Characterization of the Inner Platform of Baía Formosa - Eastern Coast of Rio Grande do Norte
Bathymetry; Sonography; Interferometric Sonar
Continental shelves, correspond to the continuation of the shallow and submerged extension of the continent. They are highly dynamic systems, which have morphological features, which allow inference about hydrodynamic conditions, sedimentation processes and still contain records that reveal the sea level changes. The eastern continental shelf of the state of Rio Grande do Norte is still little explored when compared to the northern sector. Considering the tourist and fishing importance of this area, this work aims to characterize the continental shelf adjacent to the municipality of Baía Formosa, regarding the morphological and sediment distribution aspects. In this sense, hydroacoustic methods (interferometric bathymetry and sonography) were applied, associated to seabed sediment sampling for the acoustic signal calibration. The results indicate that the study area has an average depth of 11.45 meters, ranging from a minimum of 3.06 meters to a maximum of 19.38 meters; the depth increases offshore, at an average inclination of 0.24o. Profiles perpendicular to the coastline show that the slope is smoother after 700 meters towards the coast. Additionally, the slope in the northern portion is more pronounced than in the southern one. Lines of beachrocks and rocky outcrops were identified through the integration of bathymetric data with sonographic data. Based on acoustic backscatter patterns, recognized by the contrast of gray levels and textures, morphological features were identified and 20 reflection patterns were classified. These reflection patterns will be associated with the type of material present on the seabed, for sedimentological characterization of the study area.