Abstract
Generalized beamforming is an approach to multi-channel processing of data recorded by a network of seismic stations which represents an extension of the delay-and-sum beam-forming traditionally applied in array processing. A number of geographical beam-steering points are defined, and for each beam a set of time-aligned traces derived from the network of stations are processed together so as to extract, for each step in time, a set of features corresponding to that particular beam. Applying this approach to the various regional and global network configurations, we demonstrate its usefulness for associating phases detected at individual stations and originating from the same event. The method differs from traditional phase association techniques as it provides an exhaustive search algorithm that is computationally efficient and well suited for parallel processing. We also address the problem of using a network to continuously monitor the seismic noise field. The purpose here is to determine to what extent interfering events affect the monitoring of events within a target region. In this regard, we show that one can obtain, at a given confidence level, a continuous assessment of the upper limit of magnitudes of seismic events in the target region that would go undetected by such a network.
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Bache, T.C. (1987) A knowledge-based system for analyzing data from a network of NORESS-type arrays, Papers presented at the 9th DARPA/AFGL Research Symposium, 15 to 18 June, 167–172.
Bache, T.C., Bratt, S.R., Wang, J., Fung, R.M., Kobryn, C. and Given, J.W. (1990) The Intelligent Monitoring System, Bull. Seism. Soc. Am. 80, Part B, 1833–1851.
Baumgardt, D.R. (1987) Case-based reasoning applied to regional seismic event characterization, Papers presented at 9th DARPA/AFGL Research Symposium, 15 to 18 June, 173–178.
Bratt, S.R. and Bache, T.C. (1988) Locating events with a sparse network of regional arrays, Bull. Seism. Soc. Am. 78, 780–798.
Bratt, S.R., Swanger, H.J., Stead, R.J., Ryall, F. and Bache, T.C. (1990) Initial results from the Intelligent Monitoring System, Bull. Seism. Soc. Am. 80, Part B, 1852–1873.
Goncz, J.H. (1980) Present status and dynamic planning for automatic association programs, Teledyne Geotech Report SDAC-TR-80-2.
Korhonen, H., Pirhonen, S, Ringdal, F., Mykkeltveit, S., Kværna, T., Larsen, P.W. and Paulsen, R. (1987) The FINESA array and preliminary results of data analysis, Report 5–16, Inst. of Seismology, University of Helsinki, Finland.
Kværna, T. (1989) On exploitation of small-aperture NORESS type arrays for enhanced P-wave detectability, Bull. Seism. Soc. Am. 79, 888–900.
Kværna, T. (1990) Generalized beamforming using a network of four regional arrays, Semiann. Tech. Summary 1 April – 30 September 1990, NORSAR Sci. Rep. No. 1–90/91, Kjeller, Norway.
Kværna, T. (1992) Automatic phase association and event location using data from a network of seismic microarrays, Semiann. Tech. Summary 1 October 1991 – 31 March 1992, NORSAR Sci. Rep. No. 2–91/92, Kjeller, Norway.
Kværna, T. (1992) Initial results from Global Generalized Beamforming, Semiann. Tech. Summary 1 April – 30 September 1992, NORSAR Sci. Rep. No. 1–92/93, Kjeller, Norway.
Kværna, T. (1992) Two techniques for constructing a uniform grid system covering the Earth’s surface, Semiann. Tech. Summary 1 April – 30 September 1992, NORSAR Sci. Rep. No. 1–92/93, Kjeller, Norway.
Kværna, T. and Doornbos, D.J. (1986) An integrated approach to slowness analysis with arrays and three-component seismometers, Semiann. Tech. Summary 1 April -30 September 1986, NORSAR Sci. Rep. No. 2–85/86, Kjeller, Norway.
Mykkeltveit, S. and Ringdal, F. (1981) Phase identification and event location at regional distances using small-aperture array data, in Identification of Seismic Sources: Earthquake or Underground Explosion, Husebye, E.S. and Mykkeltveit, S. (Ed.), Reidel, Dordrecht, Holland, 467–481.
Mykkeltveit, S. and Bungum, H. (1984) Processing of seismic events using data from small-aperture arrays, Bull. Seism. Soc. Am. 74, 2313–2333.
Mykkeltveit, S., Ringdal, F., Fyen, J. and Kværna, T. (1987) Initial results from analysis of data recorded at the new regional array in Finnmark, Norway, Semiann. Tech. Summary 1 October 1987 – 31 March 1988, NORSAR Sci. Rep. No. 1–87/88, Kjeller, Norway.
Ringdal, F. and Kværna, T. (1989) A multichannel processing approach to real time network detection, phase association and threshold monitoring, Bull. Seism. Soc. Am. 79, 1927–1940.
Ringdal, F. and Kværna, T. (1992) Continuous seismic threshold monitoring, Geophys.J.Int. 111, 505–514.
Ringdal, F. and Kværna, T. (1993) Generalized Beamforming as a tool in IDC processing of large earthquake sequences, Semiann. Tech. Summary 1 April – 30 September 1993, NORSAR Sci. Rep. No. 2–92/93, Kjeller, Norway.
Slunga, R. (1980) International Seismological Data Center. An algorithm for associating reported arrivals to a global seismic network into groups defining events, FOA Report C 20386-T1, Stockholm, Sweden.
Taylor, D.W.A. and Leonard, S.K. (1992): Generalized beamforming for automatic association, in Papers presented at the 14th Annual PL/DARPA Seismic Research Symposium, 16-18 September 1992, Loews Ventana Canyon Resort, Tuscon, AZ, USA.
Vinje, V., Iversen, E., Gjøystdal, H. and Åstebøl, K. (1992) Traveltime and amplitude estimation using wavefront construction, Abstract of paper presented at the 54th Meeting and Technical Exhibition of the European Association of Exploration Geophysicists, Paris, France, 1–5 June 1992.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1996 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Kværna, T., Ringdal, F. (1996). Generalized Beamforming, Phase Association and Threshold Monitoring using a Global Seismic Network. In: Husebye, E.S., Dainty, A.M. (eds) Monitoring a Comprehensive Test Ban Treaty. NATO ASI Series, vol 303. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-0419-7_24
Download citation
DOI: https://doi.org/10.1007/978-94-011-0419-7_24
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-4187-4
Online ISBN: 978-94-011-0419-7
eBook Packages: Springer Book Archive