Ten years' progress of Syowa Station, Antarctica, as a global geodesy network site

Progress of geodesy programs at Syowa Station since our former review in 1933 is summarized.As for Very Long Baseline Interferometry (VLBI),Global Positioning System (GPS),and Doppler Orbitography Radiopositioning Integrated by Satellites(DORIS),Syowa Station isa participating station in an international network and hasobtained an International Earth Rotation Service (IERS)dome number.Time series of about /years show change of position by plate motion. Detection of vertical motion by glacial isostatic adjustment is still under investigation. More than 20000 synthetic aperture radar (SAR) scenes have been received from the European Remote Sensing satellite-1 and -2 (ERS-1/-2) and the Japan Earth Resources satellite-1 (JERS-1) by the Syowa 11-m multipurpose antenna. Several case studies by interferometric SAR analyses have shown characteristic features of the ice grounding zones,ice dynamics and Digital Elevation Model (DEM)estimates.As for absolute gravimeter (AG) measurements, Syowa Station is registered as the International Absolute Gravity Basestation Network (IAGBN)0417 point. Observa tionswith an FG5 gravimeter were made for two summer seasons 5 years apart, and they showed consistent results within 2μGal difference. The superconducting gravimeter (SG) observations with a TT70 (#016 ) produced many scientific results in the two streamlines of tidal bands and normal mode bands.Especially, the first evidence of incessant excitation of the Earth 's free oscillations (background free oscillations)is noted as an important contribution from the Syowa SG observations.The Gravity Recovery And Climate Experiment (GRACE) satellite will bring an important advance for the study of ice-water-air mass circulation and its interaction with the solid-earth.The local potential fields calibrated by connecting to the station observatory data should give appropriate ground-truth information for the regional-scale satellite data,which reflects the continuing important role of Syowa