Applying SRTM digital elevation model to unravel Quaternary drainage in forested areas of Northeastern Amazonia

• Published in: Computers & geosciences Vol. 35; no. 12; pp. 2331 - 2337
• Main Authors: Mantelli, Luiz Rogério, Rossetti, Dilce de Fátima, Albuquerque, Paulo Gurgel, Valeriano, Márcio de Morisson
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2009; Elsevier
• Subjects: Applied geophysics; Earth sciences; Earth, ocean, space; Exact sciences and technology; Ilha do Marajó; Internal geophysics; Marine and continental quaternary; Northern Brazil; Paleochannels; Paleoenvironmental reconstruction; SRTM; Surficial geology; Topography; South America; Brazil; Amazonia; Marajo; Para Brazil; Brazil, Amazonia; USA, Connecticut, Hartford Basin, Newark Supergroup, Shuttle; Brazil, Para, Marajo I; Ilha do Marajó; Paleochannels; Paleoenvironmental reconstruction; Northern Brazil; Topography; SRTM; altitude; accuracy; reactivation; upper Quaternary; faults; Cenozoic; computers; Synthetic aperture radar; models; Quaternary; interferometry; Shuttle Imaging Radar; Space remote sensing; topography; data processing; digital elevation models; forests; floodplains; upper Pleistocene; channels; drainage; Phanerozoic; Holocene; radar methods; Pleistocene; meanders
• ISSN: 0098-3004; 1873-7803
• DOI: 10.1016/j.cageo.2009.04.011

There has been an increasing number of articles stressing the advantage of applying remote sensing products of synthetic aperture radar (SAR) and interferometric synthetic aperture radar (InSAR) for rapidly enhancing the volume of geological data in Amazonian areas, where forest cover is dense and high, clouds are abundant and accessibility is limited. The majority of these studies has emphasized geomorphology as a tool for both discussing tectonic reactivations during the Cenozoic and reconstructing Quaternary paleolandscapes. This work applies Digital Elevation Model (DEM) derived from the Shuttle Radar Topography Mission (SRTM) for delineating past morphological features under dense rainforest in an Amazonian lowland area. Previous use of this tool in southwestern Marajó Island (northern Brazil) helped to delineate, with exceptional precision, a paleochannel network hidden under the rainforest, which would be barely detected with other available remote sensing products. Fieldwork revealed that these paleochannels are related to palimpsest drainage systems developed mostly during the last 40,000 14C yr B.P. Measured altitudes acquired during topographic surveys attested that paleochannel areas are slightly higher than adjacent floodplains. This fact determined the successful application of SRTM–DEM for mapping paleochannels in Marajó Island. Integration of SRTM data with sedimentological information collected during fieldwork suggests paleoflows derived from continental areas located to south of the study area. This paleodrainage was active when the island was still connected to mainland. With island detachment due to reactivation of tectonic faults, the channels became abandoned and were progressively forested. The results obtained in the present study indicate that SRTM–DEM has high potential for unraveling similar morphological features from many other Amazonian areas with low topography and a dense forest cover.