Semiannual Technical Summary, 1 April - 30 September 1989
Scientific summary rept.
ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
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This Semiannual Technical Summary describes the operation, maintenance and research activities at the Norwegian Seismic Array NORSAR, the Norwegian Regional Seismic Array NORESS and the Arctic Regional Seismic Array ARCESS. The NORSAR Detection Processing system has been operated throughout the period with an average uptime of 94.9 as compared to 98.2 for the previous reporting period. A total of 1908 seismic events have been reported in the NORSAR monthly seismic bulletin. The performance of the continuous alarm system and the automatic bulletin transfer by telex to AFTAC has been satisfactory. Processing of requests for full NORSTARNORESS data on magnetic tapes has progressed according to established schedules. The generalized beamforming method, which has been developed at NORSAR and represents a new approach to associate detected seismic phases from a regional or global network, has been further tested. A data base of 77 regional and local seismic events recorded by NORESS and ARCESS has been used, and the results have been compared to output of the Assess procedure in the Intelligent Monitoring System IMS. NORSAR RMS Lg magnitude measurements have been compared to yield data recently published by Soviet scientists for Shagan River explosions. The correspondence appears to be excellent, and considerably better than the correspondence between world-wide mb and these yield estimates. However, only a few large events have been available for this study and more data will be needed before firm conclusions may be drawn. jhd
- Seismic Detection and Detectors