Advances of Submarine Groundwater Discharge Studies in South America

Submarine groundwater discharge (SGD) is the hidden portion of water that discharges into the ocean across the ocean-land interface, and it is considered one of the hydrological cycle's major components. Two decades ago, SGD in South America was undocumented, and significant advances on this field has occurred since then. This paper presents the results of SGD investigations, a compilation of the SGD estimations, and the areas lacking of data in South America. The compilation of observed SGD in South America shows that groundwater seepage from the land to the ocean occurs in many environments along the coast. Considering only the few regions for which the total SGD flux was estimated, the SGD flux (ca. 1.2 x 10(8) m(3) day(-1)) is equivalent in volume to almost 70% of Amazon River discharge. Although the study of SGD in South America has greatly advanced, many uninvestigated sites and key questions remain.