Accession Number:

ADA171683

Title:

NORSAR Detection Processing System.

Descriptive Note:

Semiannual technical summary rept. 1 Oct 85-31 Mar 86,

Corporate Author:

ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER

Personal Author(s):

• Loughran,L. B.

Report Date:

1986-05-01

Pagination or Media Count:

99.0

Abstract:

This Semiannual Technical Summary describes the operation, maintenance and research activities at the Norwegian Seismic Array NORSAR for the period 1 October 1985 - 31 March 1986. The NORSAR Detection Processing system has been operated through the reporting period with an average uptime of 98.8 per cent. Most of the downtime has been caused by disk failure and schedule maintenance at the central recording computer. A total of 1931 seismic events have been reported by NORSAR in the period. the performance of the continuous alarm system and the automatic bulletin transfer by telex to AFTAC have been satisfactory. Regular transmission by telex to AFTAC of NORESS detection lists has been initiated. Processing of requests for full NORSARNORESS data on magnetic tape has progressed without problems. About 100 regional events recorded by the High Frequency Seismic Element HFSE at NORSAR have been analyzed with respect to spectral characteristics of recorded phases. For epicentral distances within about 500 km, the Pn and Sn phases consistently show extremely strong high frequency energy. Thus, the SNR shows no drop with increasing frequency within the recorded bandwidth up to 62.5 Hz.

Descriptors:

• *SEISMIC ARRAYS
• MAINTENANCE
• NETWORKS
• THRESHOLD EFFECTS
• MAXIMUM LIKELIHOOD ESTIMATION
• UNDERGROUND EXPLOSIONS
• SEISMIC DETECTION
• SENSITIVITY
• DATA REDUCTION
• COMPUTER APPLICATIONS
• RESEARCH MANAGEMENT
• EARTHQUAKES
• NORWAY

Subject Categories:

• Seismology
• Seismic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE