Broad-band and wide dynamic-range seismic observations with a Streckeisen Seismometer (STS) at Syowa Station, East Antarctica -JARE-33 status report (1992)-

Abstract

A three component Streckeisen Seismometer (STS) was tested during wintering of the 30th Japanese Antarctic Research Expedition (JARE-30,from April 1989) at Syowa Station (69°S, 39°E), East Antarctica. The broadband and wide dynamic-range digital seismic recording was started from May 1990 by JARE-31. During the wintering season of JARE-33 (from February 1992 to January 1993), both installation conditions and data-acquisition system were improved as follows : 1) BRB (Broad-Band) velocity output was monitored by thermal pen-recorders and the digital recording system. 2) Digital recording system of LP (Long-Period) acceleration output was started. 3) UT (Universal Time) system was replaced by GPS (Global Positioning System) satellites instead of NNSS (Navy Navigation Satellite System). 4) Relation between the drift of the pendulum and temperature change was investigated by monitoring POS (Position) output. 5) Comparison of two vertical sensors under different installation conditions revealed the nature of characteristic noises. In this paper, the results of JARE-33 observations are presented. Some problems concerning maintenance of the observation system remain unsolved.