Sea level variation from a remote river in the Gulf of Paria, Trinidad

Abstract

Short-term sea level variability is investigated by analytical methods to ascertain whether there is a link between peak tidal residuals in the Gulf of Paria (GoP), Trinidad, and peak river outflow from the Orinoco on the Venezuelan mainland. Analysis of tidal data suggests that although the Orinoco delta fronts the Atlantic ocean, significant volumes of this river runoff enter into the GoP and play a role in seasonal sea level variation on the western coastline of the southernmost Caribbean island of Trinidad. The indications from various statistical analyses including harmonic, spectral and time series analyses of tide gauge data are that mean seasonal variations in water level in the north of the GoP exhibit a positive temporal correlation between the tidal residuals and the peak river discharge associated with the Orinoco's seasonal cycle. The maximal de-tided residuals are strongly correlated with maximal values of the river runoff, as well as the discharge trend, with the residual values at initial average estimates of about 12–15 cm/year.