Fig. 21

Influence of ocean currents on hyperpycnal plumes off the Río de la Plata Estuary. a Schematic representation of the depth-averaged current circulation in the southwestern Atlantic region. White circle = Estuary. The shelf (depths smaller than 200 m) is marked by white background. Ocean currents are primarily responsible for the dilution of sediment plumes at the mouth of the estuary (see Fig. 20c). From Matano et al. (2010); b Seasonal composites of chlorophyll-a concentration (mg⋅m^− 3) for the study area (white circles). Red pattern represents trends of plumes (arrows). Note heavy plume trending north during the winter season. The implication is that not all plumes routinely move offshore across the continental shelf and reach the deep sea. From Gonzalez-Silvera et al. (2006). Additional labels by G. Shanmugam