Resumo

CUADRADO, Diana G; GOMEZ, Eduardo A  e  GINSBERG, S. Susana. Transverse bedforms in a mesotidal estuary. Rev. Asoc. Argent. Sedimentol. [online]. 2003, vol.10, n.2, pp.163-172. ISSN 1853-6360.

Large transverse bedforms occur on shallow continental shelves, tidal inlets and large estuaries as a result of the strong currents in water sufficiently deep. Although Bahía Blanca Estuary is not a large estuary, its topographical and hydrodynamical characteristics allow the development of a dune field including, among other bedforms, very large dunes. Such large bedforms are rare in this kind of estuary. Large, submerged dunes of Bahía Blanca Estuary were studied to acquire additional knowledge of the different morphologies found in nature, their relationships with the dynamics of the area and the mechanisms involved in their formation. To do this, the dunes field was surveyed in detailed and classified according to height, spacing, superposition, sediment characteristics, flow structure and history. Side scan sonar and echo-sounder records were used to analyze the height and spacing and shape of the dunes. The results of several current meters deployed in the study area were used to analyze the flow structure. The current velocities and the characteristics of the bottom sediments were related to the bedforms in order to understand the factors controlling their formation.

Palavras-chave : Subaqueous dunes; Side scan sonar; Tidal currents; Bottom sediments; Bahia Blanca Estuary.

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