Gravimetry and GPS observations at Belgrano II station to test ocean tidal models.

Abstract

In the framework of a joint Argentine-German project gravimetric time series observations are being carried out at the Argentine Antarctic station Belgrano II. Two gravity meters were installed in the first half of February 2007. The set-up of the gravimeters as well as first results of the ongoing observations are discussed. Additionally, kinematic positions derived from a GPS-station at the Vahsel Bay glacier near Belgrano II can be used to get a first insight into the floating behavior of this glacier. The goal of these observations is to discriminate the effect of ocean tides and to test ocean tidal models. Since ocean tides are an important phenomenon that has to be considered in a variety of geoscientific investigations in polar regions, appropriate corrections have to be applied in the different analyses, e.g. to infer temporal mass variations from satellite data, to investigate ice-shelf dynamics and deformations, or to come up with precise station positions and velocities within a terrestrial reference system. However, the ocean tide models show larger uncertainties in the Antarctic seas and (moreover) at areas covered by ice shelves and, therefore, need to be improved. This joint Argentine-German project is a contribution to the International Polar Year 2007/2008 and its project POLENET. After completion of the recordings at Belgrano II by the end of 2007 it is planned to move the equipment to San Mart ín in order to get a second gravimetric time series during the year 2008.