Abstract

Oceanographic stations in a 12 nm transect off the upwelling focus of Punta Lengua de Vaca and adyacent area were occupied using CTD and bottles to 350 m depth on August 10 to 17, 1990. The characteristics and dynamics of coastal and oceanic waters are analyzed and interpreted by means of T-S profiles and geostrophic speed estimates. The observational period coincided with a relaxation of the coastal wind followed by an upwelling-favorable wind event, as observed "in situ" by an automatic metereological station. Differences of the temperature and salinity behavior at the coastal stations with respect to the oceanic ones are explained by intrusion of oceanic water masses and the influence of internal gravity waves. Geostrophic estimates relative to the 300 db level indicate northward currents of the order of 10 cm*s-1 in the first 100 m depth layer and southward ones under that level, consistent with the classical coastal upwelling scheme. The influence of the upwelling focus on the Tongoy and Guanaquero bays located north of Punta Lengua de Vaca is analyzed.