Research in Regional Seismic Monitoring

• Main Authors: Ringdal, F., Kremenetskaya, E., Asming, V., Kvaerna, T., Schweitzer, J.
• Other Authors: NORWEGIAN SEISMIC ARRAY (NORSAR) KJELLER
• Format: Text
• Language: English
• Published: 2000
• Subjects: Seismology; *SEISMIC DATA; KARA SEA; DETECTION; ARRAYS; SENSITIVITY; BEAM FORMING; SEISMIC WAVES; RUSSIA; SEISMIC DISCRIMINATION; EARTHQUAKES; NORWAY; BARENTS SEA; ARCTIC REGIONS; GLOBAL COMMUNICATIONS; NORTHERN EUROPE; SYMPOSIA; SURFACE WAVES; FOREIGN REPORTS; SENSITIVE REGIONAL ARRAYS; GLOBAL SEISMIC MONITORING NETWORKS; GBR(GENERALIZED BEAMFORMING); GBR METHOD; SEISMIC EVENTS; WESTERN RUSSIA; NOVAYA ZEMLYA ARCHIPELAGO; EUROBRIDGE PROFILES; LOCATION; SCREENING; SEISMIC DATA ANALYSIS; Arctic; Barents Sea; Kara Sea; Norway; Orleans; Fennoscandia; Novaya Zemlya; Spitsbergen
• Online Access: http://www.dtic.mil/docs/citations/ADA526089; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA526089

During the last decades, a network of sensitive regional arrays has been installed in northern Europe in preparation for the global seismic monitoring network under the Comprehensive Nuclear-Test-Ban treaty (CTBT). This regional network, which comprises stations in Fennoscandia, Spitsbergen and NW Russia provides a detection capability for the European Arctic that is close to mb = 2.5, using the Generalized Beamforming (GBF) method for automatic phase association and initial location estimates. We have continued our studies to use data from the regional networks operated by the Kola Regional Seismological Centre (KRSC) and NORSAR to assess the seismicity and characteristics of regional phases of the Barents/Kara Sea region, as well as the application to seismic event screening. We have studied the seismicity (i.e. seismic events apart from confirmed nuclear explosions) of the Western Russia/Novaya Zemlya region for the past 25 years, and found an average of less than one seismic event per year exceeding mb 3.5. Thus, the event occurrence in this region is so low that no event of mb 3.5 and greater located in this region should be screened out in the IDC screening process. The same consideration could apply in some other regions of the world, and the study of detailed seismicity patterns is an important part of the further screening developments. In discrimination studies, our results for the European Arctic show that the P/S discriminant should be applied with great caution in this region, and further research is required. The regional MS:mb discriminant has considerable promise, and the shorter-period energy available in surface waves recorded at regional distances can be exploited in improving the monitoring capabilities during periods with strong interfering surface waves from large distant earthquakes. We recommend that the current efforts to improve mb determinations and to reconcile the current mb values with the "historic" magnitude scale be continued. Published in Proceedings of the Annual DoD/DOE Seismic Research Symposium: Planning for Verification of and Compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) (22nd), held in New Orleans, Louisiana on September 13-15, 2000, U.S. Government or Federal Rights. The original document contains color images.