Abstract
Displacement of the fast sea ice was observed with differential kinematic GPS technique at Nisi-no-ura Cove in Lutzow-Holm Bay, Antarctica. The observations were carried out for eight months from April to December in 1998. The results were evaluated with bottom pressure gauge (BPG) measurements. Tidal displacements were obtained clearly for both measurements. From the difference between both measurements, the GPS vertical accuracy was estimated to be 1-1.5 cm. Tidal constituents derived from the GPS observations were consistent with those from the BPG observations; the “sensitivity ratios”, conversion coefficient from BPG output to sea level, derived for six major tidal components were around 0.98 and the phase lags for the major com ponents agreed within 1°. Horizontal motions on the tidal time scales were detected, but the motion is less than a few centi-meters and much less than that on the longer time scale. Thus, GPS has demonstrated the ability to monitor tides with sufficient accuracy.
