Detection capability of teleseismic events recorded at Syowa Station, Antarctica: 1987-2007

Abstract

A phase identifying procedure for the teleseismic events at Syowa Station (69.0°S, 39.6°E), Antarctica has been carried out since 1967 by use of analog and digital records of short- and long-period seismometers. After the establishment of an INTELSAT telecommunication link, several kinds of digital data have been transmitted to the National Institute of Polar Research (NIPR) for the utilization of seismic phase identification. The arrival times of several phases, such as P, PKP, PP, S, SKS have been reported to the United States Geological Survey (USGS) and International Seismological Center (ISC), then published as the "JARE Data Reports (Seismology)". In this paper, hypocentral distribution and time variations for the detected earthquakes by monitoring observation at Syowa Station was studied in the 21 year period from 1987 to 2007 by using the published Data Reports. The epicental parameters were investigated in terms of focal depth dependency and seasonal trending in the threshold range of detectable magnitude. Moreover, the detection capability of teleseismic events in the southern hemisphere was discussed in comparison with global results derived from ISC data.