Analysis of the Gravimetric Earth Tide at the San Juan Station (Argentina)

Gravity measurements at the San Juan station with a Scintrex Automated CG-5 gravity meter were analyzed in order to obtain the Earth tidal parameters of amplitude and phase-difference. The observations cover a total number of 35 days. This is the first tidal analysis based on gravity measurements for this location. The Tamura tidal development was used as normal tidal potential. Tidal parameters were estimated and analyzed with the focus on diurnal and semi-diurnal tidal waves. A root mean square error on the unit weight of 13.548 nm s⁻² was obtained as a result of the adjustment procedure taking into account the barometric pressure changes. The computed amplitude factors for the main wave constituents were compared with the corresponding parameters according to the response from the Dehant, Defraigne and Wahr (DDW) inelastic non hydrostatic Earth model. The computed local gravimetric factors differ by up to (2.7 per cent from the DDW model.

Keywords:
tidal parameters; gravity measurements