Oceanographic observations in Chilean coastal waters Between Valdiva and Concepcion

fshore. Currents and T/S fields were observed in an upwelling area off Southern Chile. The study, took place in December 1998 in the zone between Valdivia (39º48'S) and Concepción (36º48'S). Measurements included ADCP, vertical and horizontal T/S distributions, SST imaginery, and wind records. Upwelling favorable winds were observed during the study. SST images confirm the existence of upwelling processes near Mocha Island (38º22'S) and Punta Lavapié (37º08'S), where cold, salty and suboxic subsurface waters reached the mixed layer close to the coast. The semidiurnal tidal signal was separated from the ADCP records with least-squares harmonic analysis and spatial biharmonic splines. Results show spatial heterogeneity of coastal subtidal currents with upwelling processes dominating. The shallow platform inshore of Mocha Island combined with wind energy results in mixing and surfacing of the low oxygen, high nutrient water intruding from o