Improving corrections in microgravimetric surveys through modelling of ocean loading effects

The periodic movement of the oceanic waters due to tidal forces physically affects the Earth. Under this tidalloading of the oceans, the ground surface is displaced and the redistribution of mass perturbs the gravity field. Such space-time variations can attain several mierogals of amplitude. Usually, only the gravimetrie signal of the earth tide is corrected during microgravimetric campaigns, This correction is of the order of one hundred microgals. However modern gravimeters in current use have a sensitivity of 5 microgals, which is far below the amplitude of the solid tides. We propose to improve the corrections made to the measurements by taking into account the influence of the loading effect due to oceanic tides.