Advanced Regional Array Studies

• Main Author: Kvaerna, Tormod
• Other Authors: NORWEGIAN SEISMIC ARRAY (NORSAR) KJELLER
• Format: Text
• Language: English
• Published: 2001
• Subjects: Seismology; *SEISMOLOGY; SIGNAL PROCESSING; FREQUENCY; NUCLEAR EXPLOSIONS; SURFACE WAVES; DATA TRANSMISSION SYSTEMS; MONITORING; NETWORKS; SEISMIC DETECTION; SEISMIC WAVES; AMPLIFICATION; NORWAY; SEISMIC ARRAYS; FOREIGN REPORTS; Indian; Norway; Novaya Zemlya
• Online Access: http://www.dtic.mil/docs/citations/ADA400396; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA400396

We have addressed the problem of optimizing the site-specific seismic threshold monitoring method in order to achieve the highest possible automatic monitoring capability of particularly interesting areas, such as the Novaya Zemlya testing area, and the Indian and Pakistani test sites. For the Novaya Zemlya test site, where a regional monitoring network is available, we obtain a monitoring capability varying between m(sub b) 2.0 and 2.5 during normal noise conditions. Based on data from the teleseismic network observing the Indian and Pakistani tests of 1998, we obtain a monitoring capability in the range m(sub b) 2.8-3.0 for these test sites. In order to fully automate the site-specific threshold monitoring method, we have developed an automatic explanation facility for analysis of the threshold traces. In this way threshold peaks caused by events located outside the target region can be discarded from further analysis. We have also extended the site-specific threshold monitoring method to process surface waves. An important results of this study is the demonstration of the significant benefits of using a shorter period band (8.12 seconds) instead of the traditional processing band (17-24 seconds) for processing surface waves at regional disturbances during an aftershock sequence. --Original contains color plates: All DTIC reproductions will be in black and white.