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Research: National Institute for Earth PhysicsNational Institute for Earth Physics · Seismological Research · Timisoara Seismological ObservatoryRomania · Timisoara
Babeș-Bolyai, UniversityGeology-Geophysics · Bs, MsRomania · Cluj-Napoca
Article: SEISMOLOGICAL DATABASE FOR BANAT SEISMIC REGION (ROMANIA)–PART 2: THE CATALOGUE OF THE FOCAL MECHANISM SOLUTIONS[show abstract] [hide abstract]
ABSTRACT: A high quality Catalogue of Focal Mechanism Solutions of the earthquakes occurred in the Banat Seismic Region (Romania) (CFMSBSR) is presented. It comprises focal mechanism solutions (FMS) for 140 events, spanning 47 years (1959–2006). CFMSB includes three kinds of the FMS: i) collected FMS with their original parameters, ii) compiled FMS with modified parameters, iii) new FMS.Journ. Phys. 10/2008; 53:7-8.
Conference Proceeding: The Study of the 20th Century Strong Romanian Earthquakes using Historical Iinstrumental Data – a Success of EUROSEISMOS 2002-2006 ProjectE. Oros, V. Oros[show abstract] [hide abstract]
ABSTRACT: In this paper we present the main results obtained from the study of several Romanian earthquakes using the data gathered into the framework of EUROSEISMOS 2002-2006 Project. The sources parameters of the earthquakes occurred in the western part of Romania (often called Banat Seismic Region, BSR) have been reappraised using original historical seismograms and bulletins. Thus, new locations, depths and magnitudes of the strongest events occurred at the beginning of 20 th Century were determined on instrumental data basis. Focal mechanisms solutions for two important earthquakes have been estimated, too. In addition, the new database recently elaborated for BSR (Oros et al., 2008) has a section that comprises all historical seismograms converted in digital format were obtained using Teseo software and a conversion routine. Many papers containing these results published and presented on last years. Materials and Methods The study of the strongest western Romanian earthquakes occurred in the first half of the 20 th Century used only historical instrumental data collected and scanned into the framework of EUROSEISMOS 2002-2006 Project: i) 209 seismograms scanned and archived at INGV Rome (Sismos facility); ii) seismic bulletins: the ISS seismic bulletins and the single stations, observatories and/or seismological network bulletins (www.storing.ingv.it /es_web). These materials and data were processed and analysed using IT technologies and modern methods following the next steps: i) collecting all the information about each event from the seismic bulletins: time arrivals of the seismic phases, amplitudes, waves periods, duration of the seismic signals, macroseismic data, etc.; ii) processing seismograms using the Teseo software (http://sismos.ingv.it/teseo/): vectorization and signal correction based of instrumental constants to obtain the digital seismograms; iii) developing computer programmes to correct and to convert the digital seismograms to Seisan waveform formats; iv) analysing the digital seismograms by Seisan software package to obtain the main focal parameters: origin time, geographical coordinates of the epicentres, focal depths, source characteristics (dimensions, stress drop), spectral parameters (corner frequency, omega zero), seismic moment and magnitudes (Mw) and focal mechanisms solutions (Fig. 1). All digital historical seismograms obtained for the earthquakes occurred into BSR through EUROSEISMOS project and other archives feed a new elaborated database (Oros et al., 2008a, 2008b) (Fig. 2).31 st General Assembly of the European Seismological Commission ESC 2008 Hersonissos, Crete, Greece, 7-12 September 2008, Hersonissos, Crete; 09/2008
Article: THE APRIL-AUGUST 2002 MOLDOVA NOUĂ EARTHQUAKES SEQUENCE AND ITS SEISMOTECTONIC SIGNIFICANCE *Eugen Oros[show abstract] [hide abstract]
ABSTRACT: Starting with 19 April 2002, a series of crustal earthquakes occurred near the Romanian – Serbian border, South of the Banat seismic region, into the Danube seismogenic zone. Until the end of August 2002, the stations of the Banat seismic network recorded 70 earthquakes (1.8 ≤ M D ≤ 4.8) with the epicenters clustered within a small area, elongated in North-South direction and located near the town of Moldova Nouă. In this time interval, two main-shocks occurred, on 24 May 2002 (M D = 4.8) and on 2 August 2002 (M D = 4.6). Significant damages (Io = VI-VII MSK) were reported in the epicentral (Moldova Nouă) area. Temporal distribution of the earthquakes indicates at least three stages of strain release. The focal mechanisms derived from P first-motion polarities, obtained for the first time for the Moldova Nouă area, exhibit: i) a dominant normal faulting (23 May 2002, M D = 3.8) and ii) a strike-slip faulting with a large normal component (for the two largest events). The fault plane oriented N–S and dipping around 60º to the West is practically identical for all three events. The sequence appears to have occurred on the southern segment of the Oraviţa Fault.Revue roumaine de geophysique. 03/2004; 48:49-68.
Eugen OrosStudii si Cercetari de Geofizica. 03/2003; 41:111-125.
Conference Proceeding: The M6.4, 26th January, 1916 Earthquake under Review: ew Data on the Seismicity of Fagaras Seismogenic Region (Romania)[show abstract] [hide abstract]
ABSTRACT: This paper presents an instrumental review of the strongest crustal Romanian earthquake occurred last Century, namely the M6.4, 26 th January, 1916 event. The earthquake occurred in Fagaras Seismogenic Zone that lies in the central part of South Carpathians. The maximum intensity reported by different authors for this event is Imax=9MM (Atanasiu, 1961) or Imax=8MSK (Oncescu et al., 1999; Shebalin et al., 1998). The data obtained from the historical seismograms and bulletins were used to re-determine its main focal parameters using modern methods. Thus, new geographical coordinates of the epicenter, focal depth, magnitudes and focal mechanism solution have been derived by processing the data using Seisan Software package (Havskov and Ottemoler, 2004). In comparison with previous parameters, our results bring some new information very useful for the local and regional seismicity analysis and modeling Materials and Methods The data used in the paper derived from: i) 42 digitized historical seismograms recorded by 15 European seismic stations (Figure 1 and Figure 2); ii) Bulletins (arrival times of P, S and R/L phases, coda, amplitudes and periods). All these materials were obtained into the framework of EUROSEISMOS 2002-2006 Project (www.storing.ingv.it/ es_web).31 st General Assembly of the European Seismological Commission ESC 2008 Hersonissos, Crete, Greece, 7-12 September 2008, Hersonissos, Crete; 09/2008