CONICET | Buscador de Institutos y Recursos Humanos

The narrow Beagle Channel in Tierra del Fuego, southernmost South America, is not included in global ocean tide models such as FES2004. Therefore, tide gauge observations in the channel are of particular value for the understanding of the tidal hydrodynamics between the Atlantic and Pacific oceans in this region. A pressure tide gauge was operated at Harberton on the northern shore of the Beagle Channel from February 2005 for almost one year. The instrument was moored on the sea floor in a depth of 10 m. Based on these data continuous sea-level record was derived with an estimated accuracy better than 1 cm for a single value. The tidal signal was extracted from the recorded sea-level by a harmonic analysis. As a result, the harmonic constants for 16 constituents were determined along with estimates of their accuracy. Two additional tide gauges were included in the analysis in order to obtain insights into the propagation of the tidal waves through the Beagle Channel. A tidal analysis of available tide gauge data from Ushuaia (Argentina) and Puerto Williams (Chile) yielded tidal parameters for both locations which are compared with the results for Harbenton. The consistency of the obtained picture of the tidal wave propagation with a global ocean tide model at either ends of the Beagle Channel is discussed. In addition to diurnal and semi-diurnal constituents, the occurrence of shallow-water tides is addressed. Non-tidal sea-level variations are investigated on the basis of the residual record from Harberton. The inverse barometer effect as the dominating form of atmospherically driven variations is quantified through the correlation of the sea-level changes with air pressure variations. Finally, the water temperature and salinity time series recorded by the Harberton tide gauge arepresented. A few geophysical and oceanographical implications of the obtained results are outlined.

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