Circulación de fondo inferida a partir de los patrones de distribución de sedimentos en el golfo San José, Patagonia

PEDRO BARON; AUGUSTO CÉSAR CRESPI-ABRIL; GASPAR SORIA; GABRIELA WILLIAMS; RODRIGO HERNADEZ-MORESINO

CBA

Jornada; Jornadas Ciencias del Mar; 2018

Sediment samples were collected in San José Gulf (SJG), PatagoniaArgentina, during seasonal water column stratification (spring 2016- summer2017). This semi-enclosed basin is mainly affected by tidal circulation thatprevent stratification of its western hydrographic domain (WHD) and resulting theformation of a thermal front between this and the stratified eastern hydrographicdomain (EHD). A conceptual model of bottom hydrodynamics was inferred based onsediment`s grain-size trends. Asymmetric dominant tidal currents affect bottomsediment distribution. A general northward transport is dominant at the WHD,while at the EHD there is a seasonal shift in the transport direction. There, anet northward transport with a counterclockwise gyre dominates bottomhydrodynamics at the end of the thermal front formation, conditioned byresidual currents. In contrast, a net southward circulation likely driven bystrong westerly winds throughout autumn and winter prevails at the beginning ofthe water column stratification. The inferred sediment transport suggests a netloss of material that has to be recovered by tidal currents entering throughthe mouth and coastal sources as runoff and/or aeolian dust.