Seismological observations by a three-component boadband digital seismograph at Syowa Station, Antarctica

A three-component broadband STS (Streckeisen seismometer) seismograph was installed at Syowa Station in 1989,to obtain precise (digital) seismic record for the study of the earth's interior and earthquakes. The STS observation system at Syowa Station is introduced and some examples of digital seismogram are shown in this paper. The STS system has two different outputs, BRB (Broad-Band : 0.1∿20s/0.1∿360s) and LP (Long-Period : longer than 20s), with a dynamic range of at least 120dB. Seismic signals are recorded in digital form together with analog seismogram for monitoring. The BRB output is currently recorded with a longterm thermal pen recorder and the digital recording system by use of personal computers, while the LP output is recorded with the pen recorder and the cassette logger. Well recorded events, most of these are large events, are compiled into floppy disks from the digital recording system approximately once a week. The digital records were transmitted successfully to National Institute of Polar Research, Japan via the satellite telecommunications system