Abstract
Data recorded with the Bucovina Romanian Seismic Array (BURAR) seismic array between January 2005 and December 2008 were analyzed to verify the monitoring capabilities of regional and distant seismicity. For this time interval, nearly 35,000 events detected by BURAR and identified in seismic bulletins (Preliminary Determination of Epicenters and Romanian Earthquake Catalogue) were investigated using parameters as backazimuth, epicentral distance and magnitude. A remarkably detection capability is emphasized for teleseismic observations (Δ > 20°). BURAR onsets could be associated to almost 60% of all events in the teleseismic distance, with a magnitude detection threshold of 4.5 (mb). When no threshold magnitude is applied, the full detection capability of BURAR is in the same order as the performance of GERES array, which is one of the most sensitive stations in Central Europe. For regional events, detection capability decreases to about 16% of all events within regional distance range. The site conditions (crustal structure and high frequency cultural noise) as well as array dimension, affect the signal coherency and reduce the array detection capability for regional events. For both teleseismic and regional distances, a monthly variation of BURAR detection capabilities has been found; the number of events detected during the summer time is diminished by the specific seasonal human activity and atmospheric conditions (thunderstorms). To prove the good detection capability of the BURAR for teleseismic distances, a comparison with the observations of the Romanian Real Time Network in terms of magnitude and epicentral distance was carried out. The higher signal detection capability of BURAR is due to the array techniques applied in data processing, which enhance the signal-to-noise ratio. The monitoring performed by the BURAR seismic array provides a good azimuthal coverage of the regional and distant seismicity, in a large range of epicentral distances.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Borleanu F, Rogozea M, Ghica D, Popescu E, Popa M, Radulian M (2008) Romanian earthquakes analysis using BURAR seismic array. Rom Rep Phys 60(1):135–143
Fyen J (1989) Event processor program package. In: NORSAR semiannual technical summary, Scientific Report 2–88/89, 1 October 1988–31 March 1989, NORSAR, Kjeller, Norway
Fyen J (1990) Diurnal and seasonal variations in the microseismic noise level observed at the NORESS array. Phys Earth Planet Inter 60:252–268
Fyen J (2001) NORSAR seismic data processing—user guide and command reference. NORSAR (contribution 731) Kjeller, Norway
Ghica D, Schweitzer J (2007) Automatic data processing at BURAR seismic station. In: Proceedings of international symposium on strong Vrancea earthquakes and risk mitigation, 4–6 October 2007, Bucharest, pp 164–169
Ghica D, Radulian M, Popa M (2004) BURAR: detection and signal processing capabilities. Rom Rep Phys 56(4):777–799
Ghica D, Radulian M, Popa M (2005) Noise level analysis for BURAR seismic array, Romania. EGU General Assembly 2005, Austria, poster presentation EGU05-A-04100
Grigore A, Grecu B, Rizescu M, Ionescu C, Ghica D, Popa M (2004) A new seismic station in Romania: Bucovina seismic array. Rev Roum Géophys 48:69–72
Kennett BLN, Engdahl ER, Buland R (1995) Constraints on seismic velocities in the Earth from travel times. Geophys J Int 122:108–124
Mykkeltveit S, Bungum H (1984) Processing of regional seismic events using data from small-aperture arrays. Bull Seismol Soc Am 74:2313–2333
Posgay K, Takacs E, Szalay I, Bodoky T, Hegedus E, Kantor JI, Timar Z, Varga G, Berczi I, Szalay A, Nagy Z, Papa A, Hajnal Z, Reilkoff B, Mueller S, Ansorge J, De Iaco R, Asudeh I (1996) International deep reflection survey along the Hungarian Geotraverse. Geophysical Transactions 40(1–2):1–44
Radulian M, Mandrescu MN, Panza GF, Popescu E, Utale A (2000) Characterization of Seismogenic zones of Romania. Pure Appl Geophys 157:57–77
Schweitzer J (1992) The GERES contribution to the GSETT-2 experiment 1991. In: Advanced waveform research methods for GERES recordings. DARPA Annual Report No. AFOSR-90–0189 Scientific Report No. 2, PL-TR-92–2142, ADA253686, pp 25–49
Schweitzer J (2001) Slowness corrections—one way to improve IDC products. Pure Appl Geophys 158:375–396
Schweitzer J, Fyen J, Mykkeltveit S, Kværna T (2002) Seismic arrays. In: Bormann P (ed) New manual of seismological observatory practice, Potsdam. IASPEI, Boulder, p 51
Stec K (2007) Characteristics of seismic activity of the Upper Silesian Coal Basin in Poland. Geophys J Int 168:757–768
Wessel P, Smith WHF (1995) New version of the Generic Mapping Tool released. EOS Trans. AGU, p 329 (see also URL: gmt.soest.hawaii.edu)
Wiejacz P, Kowalski P (2007) Comparison of ISC seismic event locations with data of Polish mining industry. IUGG General Assembly, Italy, presentation
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ghica, D.V. Detection capabilities of the BURAR seismic array—contributions to the monitoring of regional and distant seismicity. J Seismol 15, 487–506 (2011). https://doi.org/10.1007/s10950-010-9204-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10950-010-9204-9