Analysis of tectonic-controlled fluvial morphology and sedimentary processes of the western Amazon Basin: an approach using satellite images and digital elevation model
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Data
2007-12-01
Autores
Silva, Clauzionor L.
Morales, Norberto [UNESP]
Crósta, Alvaro P.
Costa, Solange S.
Jiménez-Rueda, Jairo R. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Academia Brasileira de Ciências
Resumo
Uma investigação do controle tectônico da morfologia fluvial e dos processos sedimentares de uma área localizada a sudoeste da cidade de Manaus, na Bacia do Amazonas, foi conduzida a partir do uso de dados de sensores remotos orbitais. Nessa região, o baixo gradiente topográfico representa o principal obstáculo para a análise morfotectônica usando métodos convencionais. O uso de dados de sensores remotos pode contribuir significativamente para superar essa limitação. Desse modo, dados de sensoriamento remoto, compreendendo modelo digital de elevação (DEM) obtido pelo Shuttle Radar Topographic Mission (SRTM) e imagens Landsat TM, foram utilizados para essa investigação. Técnicas avançadas de processamento de imagem foram empregadas para realce de imagens topográficas e sua elaboração tridimensional, permitindo desse modo, a interpretação dos elementos morfotectônicos. Isso permitiu o reconhecimento de principais compartimentos tectônicos, diversas feições morfoestruturais e formas de relevo relacionadas à evolução neotectônica dessa porção da Bacia do Amazonas. Feições como escarpas de falha, padrão anômalo na drenagem, alinhamentos de relevo, vales e divisores d'água foram realçados nas imagens como notáveis lineamentos ao longo das direções NE-SW, NW-SE, E-W e N-S. Essas feições foram associadas à geometria de estruturas do tipo horste e gráben alternados, este último preenchido por unidades sedimentares recentes. A interpretação morfotectônica usando essa técnica mostrou-se eficiente e permitiu o reconhecimento de novas feições tectônicas as quais foram denominadas de Gráben Assimétrico Ariaú, Bacia Romboédrica de Manacapuru e Gráben Castanho-Mamori.
An investigation of the tectonic controls of the fluvial morphology and sedimentary processes of an area located southwest of Manaus in the Amazon Basin was conducted using orbital remote sensing data. In this region, low topographic gradients represent a major obstacle for morphotectonic analysis using conventional methods. The use of remote sensing data can contribute significantly to overcome this limitation. In this instance, remote sensing data comprised digital elevation model (DEM) acquired by the Shuttle Radar Topographic Mission (SRTM) and Landsat Thematic Mapper images. Advanced image processing techniques were employed for enhancing the topographic textures and providing a three-dimensional visualization, hence allowing interpretation of the morphotectonic elements. This led to the recognition of main tectonic compartments and several morphostructural features and landforms related to the neotectonic evolution of this portion of the Amazon Basin. Features such as fault scarps, anomalous drainage patterns, aligned ridges, spurs and valleys, are expressed in the enhanced images as conspicuous lineaments along NE-SW, NW-SE, E-W and N-S directions. These features are associated to the geometry of alternated horst and graben structures, the latter filled by recent sedimentary units. Morphotectonic interpretation using this approach has proven to be efficient and permitted to recognize new tectonic features that were named Asymmetric Ariaú Graben, Rombohedral Manacapuru Basin and Castanho-Mamori Graben.
An investigation of the tectonic controls of the fluvial morphology and sedimentary processes of an area located southwest of Manaus in the Amazon Basin was conducted using orbital remote sensing data. In this region, low topographic gradients represent a major obstacle for morphotectonic analysis using conventional methods. The use of remote sensing data can contribute significantly to overcome this limitation. In this instance, remote sensing data comprised digital elevation model (DEM) acquired by the Shuttle Radar Topographic Mission (SRTM) and Landsat Thematic Mapper images. Advanced image processing techniques were employed for enhancing the topographic textures and providing a three-dimensional visualization, hence allowing interpretation of the morphotectonic elements. This led to the recognition of main tectonic compartments and several morphostructural features and landforms related to the neotectonic evolution of this portion of the Amazon Basin. Features such as fault scarps, anomalous drainage patterns, aligned ridges, spurs and valleys, are expressed in the enhanced images as conspicuous lineaments along NE-SW, NW-SE, E-W and N-S directions. These features are associated to the geometry of alternated horst and graben structures, the latter filled by recent sedimentary units. Morphotectonic interpretation using this approach has proven to be efficient and permitted to recognize new tectonic features that were named Asymmetric Ariaú Graben, Rombohedral Manacapuru Basin and Castanho-Mamori Graben.
Descrição
Palavras-chave
morfotectônica, morfoestrutura, neotectônica, Bacia do Amazonas, morphotectonics, morphostructural, neotectonics, Amazon Basin
Como citar
Anais da Academia Brasileira de Ciências. Academia Brasileira de Ciências, v. 79, n. 4, p. 693-711, 2007.