LONG-PERIOD GRAVITY TIDES AT THE SOUTH POLE

Gravity observtions obtained in 1970 at Amundsen-Scott station at the geographic South Pole by an electrostatically nulled LaCoste-Romberg gravitimeter have been analyzed for the long- period tides. Two records of lengths 50 and 57 days, separated by a large gap, were analyzed using a least squares method. Instrumental drift and a strong correlation with barometric pressure are identified to be the major sources of noise. Our results for the gravimetric factor and the phase lead of long-period tides are delta = 1.159 +- 0.010 and alpha = 0.0073 +- 0.0194 days. The largest constituent responsible for these values is the fortnightly tide Mf. Within conservative errors these numbers are consistent with seismological results and at most a small correction for ocean loading. -Authors