Sediment bank contribution to form a vortex and a deep scour hole on tidal channel meander

MAVO MANSTRETTA, G.M.; ARENA, M.; PERILLO, G.M.E.; VITALE, A.J.; PAYARES PEÑA, N.B.; FERRONATO, C.; LEKANDA, A.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022 vol. 115

0895-9811

environments. Tidal channels can be subject to the most energetic processes. Therefore, changes in their geomorphologyrequire continuous updates. Through oceanographic surveys, were collected in situ hydrodynamic,bathymetric, and sedimentological data in a section of the Canal del Medio in the Bahia Blanca Estuary(southwest of the Buenos Aires Province, Argentina) to examine the possible effect that the presence of a sedimentbank can have on the tidal current pattern within a specific meander. An unusual elliptical deep scour holewas detected with a depth of 12.60 m in the thalweg of the meander (tidal range is about 3 m). Based on the data,it was found that the maintenance of the scour hole is possible because of a vortex forced by the presence of anelongated sandy bank connected to the tidal channel bank that acts as a hydrodynamic barrier to the currents,inducing the modification of the meander pattern.