Utilização do modelo geopotencial SGG-UGM-2 para caracterização gravimétrica da elevação do Rio Grande

Abstract

Gravimetry is the branch of geophysics that uses the elements of the gravity field to study the Earth. The configuration of the gravity field results mainly from the density variations of the constituents of the Earth's interior. With technological advances, it is now possible to carry out gravimetric studies using satellite data in areas considered difficult to access. One such region that is increasingly attracting the interest of researchers is the Rio Grande Rise (ERG), which is located approximately 870 km off the southeast coast of Brazil. The structure of the ERG is composed of seamounts, guyots, aseismic ridges and morphological elevations formed from magmatic events, called volcanic buildings. Studies focused on investigating the geological formation of the ERG conducted in recent decades have indicated the existence of favorable and permissive areas for cobalt-rich crust formation, ferromanganese crusts, and manganese nodules. In this work, the geological features present in the ERG were investigated from air-gravity and Bouguer anomaly data calculated from the SGG- UGM-2 geopotential model. The enhancement filters First Vertical Derivative (1°DV), Analytical Signal Amplitude (ASA), Regional/Residual Separation and, directional cosine were applied to these data. The results obtained allowed locating and defining the geometries of volcanic buildings and gravimetric lineaments. Furthermore, it was possible to divide the identified volcanic buildings into three groups and associate these with the ERG formation stages. Furthermore, for specific portions of the ERG, for which a greater amount of geophysical and geological information is available, it was possible to indicate promising areas for further mineral prospecting studies.