Preliminary results of geomorphologic characterization in Bahía San Blas (Argentina)

BEIGT, D.; CUADRADO, D.G.; PICCOLO, M.C.

Bahía Blanca

Simposio; ECSA 44 Science and Management of Estuaries and Coasts: A tale of two hemispheres; 2008

Estuarine Coastal Science Association-Instituto Argentino de Oceanografía

At the south of Buenos Aires Province (Argentina) there is a coastal feature namedBahía Anegada, a bay which comprises several islands and shoals and a smaller bay(San Blas). San Blas is characterized by a 3-km wide and a 27-m deep tidal channel,which is bounded by a steep gravel beach on one side and a sandy island on the otherside. An island formed by gravel and coarse sand beach ridges which prograded to thecoast during the Holocene is located at the coast of San Blas bay. A strong oysteraquaculture activity was developed in the area since some years ago.The area presents different coastal scenarios in nearly 20 km of coast. Thus, from Southto North, coastal sand dunes, gravel beaches, salt marshes and wave cut platforms arepresent along the coast as a response to the coastal energy spatial variation, whichdiminishes towards the inner channel. A sand spit is present as a result of littoral drifttowards the channel mouth. Accretional and erosional zones are distinguished in thestudied area.The main processes that affect the area are caused by winds and waves. Therefore,meteorological data from a station located in the area and the results of a wavenumerical model (wave height and direction) provided by the National MeteorologicalService was analyzed during six month(s). A preliminary map showing the mainfeatures of the coastal geomorphology as well as preliminary results relating the littoraldynamics along the study area with its geomorphological features are presented.