The Norwegian Seismic Array (NORSAR)

This report describes the operation, maintenance and research activities at the Norwegian Seismic Array NORSAR for the period 1 April to 30 September 1982. The uptime of the NORSAR online detection processor system has averaged 92.3, as compared to 91.9 for the previous period. Most of the downtime was caused by CPU and disk drive problems. The new DP system implemented on IBM 4331MODCOMP on 24 September is described in some detail in Section III. Section IV describes improvements, modifications and maintenance activity in connection with the NORSAR field instrumentation. The research activity is briefly described in Section VI. Subsection 1 discusses on-line event detection and location based on NORESS data. Subsection 2 presents the continuing extensive analysis of noise level variations at the NORESS stations. Subsection 3 gives some preliminary results from the Eastern Kazakh test site. Subsection 4 presents preliminary results for research into seismic energy and stress drop from moment tensor analysis. Subsection 5 presents the Global Digital Seismograph Network software package developed at NORSAR to provide seismic waveform data from SRO, ASRO and DWWSSN stations.