Banca de QUALIFICAÇÃO: LAVINIA DA CRUZ BARBALHO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LAVINIA DA CRUZ BARBALHO
DATE: 21/05/2021
TIME: 08:30
LOCAL: Videoconferencia -
TITLE:

Seismic stratigraphic framework of the tidal channel system of the Parnaíba River Delta (Northeastern Brazil) as an indicator of variations in the Quaternary relative sea level

KEY WORDS:

Parnaíba River Delta; Holocene evolution; Tidal Channels; Remote Sensing; Seismic Stratigraphy; Depositional Systems Tracts

PAGES: 88
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The Parnaíba River Delta (PRD) is located in the Equatorial Margin of Brazil, approximately 1.100 km east of the Amazonas River and 1.200 km northwest of the São Francisco River. That delta is dominated by waves and influenced by tides, which is a rare example of a depositional system that keeps its features in a natural state. The data from remote sensing of satellites (Alos Palsar and Landsat 8 images) and high resolution seismic data, that are presented and interpreted for this study, helped both in the creation of a digital terrain model and a geomorphological map of the study area, as well as in the seismostratigraphic analysis of the western portion of the Parnaíba River Delta, specifically its tidal channel system. From the compilation of digital image processing procedures (altimetric correction and statistical analysis of spectral bands) and sequence stratigraphy concepts, based on the use of seismic stratigraphy, this study sought to expand our understanding of the Holocene evolution of that delta. The satellite data processing step involved the conversion of the ellipsoidal height to the orthometric height of the Alos Palsar scenes, as well as the identification, from the Landsat 8 scene, the most suitable RGB compositions for differentiating the features of the fluvio- lacustrine plains, paleo-dunes, mangroves, beaches and recent dunes in the region of interest. The other step, the analysis of the seismic section, covered the description and interpretation of the reflector patterns, the seismofacies, the types of secondary paleochannels and their filling patterns, the seismostratigraphic units and their boundary surfaces. From that, two stages in the curve of base level change were recognized, represented by the transgressive (TST) and high stand (HST) system tracts. The results tend to contribute to the debate about the lobe switching process in the PRD, as well as in the correlation between the evolution of that sector of the Brazilian coast and the fluctuations in the relative sea level that occurred during the Quaternary

BANKING MEMBERS:
Presidente - 2218779 - HELENICE VITAL
Externo à Instituição - Antônio Jorge Campos Magalhães
Externo à Instituição - JOSÉ MARIA LANDIM DOMINGUEZ - UFBA
Externo à Instituição - PAULO CÉSAR FONSECA GIANNINI - USP