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– Map of epicenters for PECBSR (1443–2006). Magnitudes are in M D . Dashed line bounds Banat Seismic Region. The continuous line limits the critical area around BSR (details in text).
Source publication
The most comprehensive Seismological Database for Banat Seismic Region
has been achieved. This paper refers to the essential characteristics of the first
component of this database, namely the Parametric Earthquakes Catalogue for the
Banat Seismic Region (PECBSR). PECBSR comprises 7783 crustal earthquakes
(3 ≤h ≤25 km) with 0.4 ≤Mi ≥5.6 (Mi is ML,...
Context in source publication
Context 1
... catalogue finally comprises 7783 earthquakes. Magnitudes and intensities range between 0.2 ≤ Mi ≥ 5.6 (Mi are magnitudes collected from original sources and may be M D , M L , M S , M W , mb) and 2.0 ≤ Ii ≥ 9.0, respectively (Ii is maximum observed or epicentral intensity). Fig. 1 displays a map of earthquake epicenters (locations obtained using minimum three stations arrival times, explosions have been excluded as far as possible). Their distribution show many clusters of epicenters related with areas of high seismic activity and with destructive potential historicaly confirmed (I O = VIII O EMS) [10]. Two ...
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Citations
... The seismicity of Banat area is a moderate one, with earthquakes of crustal type [7]. The magnitudes in the area are between MW = 0.2 ÷ 5.6 [8], as presented in Table 1 [9], and according to the Romanian Design Code, the peak ground acceleration for Timisoara is PGA = 0.20g [10]. Following the considered PGA, there was determined the most probable macroseismic intensity, based on Equation 1 [5], which is IX EMS-98, as presented in Figure 4 [11]. ...
... The most active seismogenic region in the crustal domain is the Banat zone and is located at the contact area between the Pannonian Depression and the Carpathian Orogen. The seismicity of the Banat area is significant, earthquakes occurring in the upper crust (85% up to 15 km depth; Oros et al., 2008) often exceed the moment magnitude 5.0 and are followed by long sequences of aftershocks. The strongest event with a magnitude of 6 belongs to the historical part of the catalog August 4, 1444 and had an epicentral intensity of VII MSK (Oncescu et al., 1999). ...
In the current context of rapid urban growth, a substantial impact on the evaluation of seismic hazard and risk is given by the regional and local ground motion variability. In this paper, a review of up-to-date seismic hazard studies is envisaged with emphasis on the complex physics-based waveform modeling method neo-deterministic seismic hazard analysis (NDSHA) application at national and local scales to deliver a powerful input to risk analyses for Romania. Applied at a national scale, NDSHA realistically reproduces the macroseismic field of Vrancea intermediate-depth events while at the local scale, the observed and the synthetic signals display similar features. The local site amplification was computed for Bucharest city, and it provides very useful quantities to study the local effects in the frequency domain. In the context of Vrancea seismicity, the innovative NDSHA has proved to be very efficient and provides a consistent estimate for engineering design and risk assessment.
... We use 93 earthquakes (Fig. 4) with fault plane solutions in terms of nodal planes to describe the faults from a seismological point of view. The fault plane solutions have been obtained as in [11], from [14,18,19]. The earthquakes catalogue used is the Romplus catalogue [20] and a local catalog with earthquakes from south-west Romania [19]. ...
... The fault plane solutions have been obtained as in [11], from [14,18,19]. The earthquakes catalogue used is the Romplus catalogue [20] and a local catalog with earthquakes from south-west Romania [19]. ...
The main target of this paper is to established a correlation between the seismicity of the Western part of Southern Carpathians (Romania) and the active tectonic (faults systems) of the area, the second target is to create a specific database of the faults (ROmanian DAtabase of SEismogenic Faults-RODASEF) in SHARE manner, for seismic hazard assessment process. In the studied area, we highlit the main faults form Hateg Basin, Moldova Noua-Oravita Basin, Caransebes-Orsova basin (Teregova) and Orsova-Mehadia-Cornereva faults system, which generate seismic sequences such as:
... Generally, impulsive phenomena (compatible with the crustal systems present in the seismic region of Banat, Romania) are characterized by high vertical accelerations in short periods, releasing all the energy content [52], [53]. ...
... As proposed by [53], the Seismological Database for Banat Seismic Region, SDBSR, is a useful tool for quantifying the seismic hazard of the area to guarantee accurate forecasting of seismic risk mitigation plans. ...
... In particular, the SDBSR database has been developed in detail since Romania is a border territory, the local seismic risk is influenced by earthquakes generated in neighbouring areas such as Hungary, Serbia, and Bulgaria, and also in the Romanian provinces, i. e Transylvania and Western Muntenia as well. Thus, the database consists mainly of two main parts, the first, essentially related to the number of earthquakes generated in the Banat region according to the Parametric Earthquakes Catalogue for BSR, PECBSR, the second one, take into consideration the extent of the focal mechanisms that generated the reference events in a given period referred to the Catalogue of Focal Mechanism Solutions for BSR, CFMSBSR [53]. ...
... Studiul nostru s-a bazat pe două compilații, respectiv un catalog parametric al cutremurelor de pamânt și un catalog al mecanismelor focale. Compilațiile au fost elaborate folosind următoarele surse de date: i) catalogul parametric de cutremure elaborat în cadrul proiectului PN 09 30 01 06 (Oros et al., 2008;Oros, 2011), catalogul național Romplus (Oncescu et al, 1999) Secvența seismică din 1991 a fost monitorizata cu o rețea locală alcatuită din stații fixe (TIM, SSR, BZS, GZR) și stații temporare (BANLOC, DETA, GHILAD, SOCA, FOLEA, OFSENIȚA). Au fost relocalizate 120 de evenimente produse în perioada Iulie-Decembrie 1991 aplicând metoda JHD (Pujol, 2000) și un nou model de viteze, simplu stratificat, cu limitele Moho la 31 km (vPn=7,98 km/s) și respectiv Conrad la 20 km (vPb=6,503 km/s), viteza undelor directe vPg=5,582 km/s si raportul vP/vS=1,74 (Oros, 2011). ...
Modelling the causal relationship between the stress field specific to a complex geological environment as structure and composition and how it reacts and manifests itself through specific, observable and measurable deformations (fracturing and propagation of fractures, seismic faults, seismicity), is the key to understanding seismogenic processes in a seismic cycle defined simplistically by accumulation and release of seismic energy and is, implicitly, the necessary scientific support for the realistic assessment of seismic hazard and risk. We investigated this relationship in the area of the Banloc-Voiteg seismogenic structure, one of the most important sources of seismic hazard associated with crustal earthquakes in our country. The seismic activity of the Banloc-Voiteg structure, a well-defined structure in the space of the Banat seismogenic zone (Radulian et al., 2000), is marked by two major seismic sequences (Imax = VIII0MSK). The first sequence, documented based on a small number of macroseismic and instrumental data (Oros and Oros, 2009; Oros, 2011), occurred in 1915 with the mainshock of 19.10.1915 (Mw = 5.3)preceded by two shocks produced in a few minutes with Mw = 5.1 (09.10.1915, Ho = 21: 24: 59.3) and Mw = 4.7 (09.10.1915, Ho = 21: 31: 19.2). ) (Oros and Oros, 2009). The second sequence, with a particularly complex evolution in space and time, instrumentally monitored with temporary stations and studied macroseismic in detail (Oros et al., 1994) is characterized by two distinct phases defined by two strong earthquakes produced on 12.07.1991 (Mw = 5.6, Imax = VIII0MSK) and respectively on 02.12.1991 (Mw = 5.5, Imax = VIII0MSK). Studies conducted so far on Western Romania have focused on seismicity, tectonics and stress field (example: Bălă et al., 2015; Bălă and Răileanu, 2017; Oros, 2011; Polonic, 1985; Radulian et al., 2000), investigation fractal characteristics of source parameters (example: Popescu and Radulian, 2001), modelling of active tectonics and seismic hazard (ex Oros and Oros, 2009; Oros, 2011; Oros et al., 2018; Polonic, 1985; Polonic and Malița, 1997). In this chapter, we present a detailed analysis of the Banloc-Voiteg area, focused on the 1991–1992 seismic sequence, seismicity and crustal stress field, contemporary in their relationship with local and regional tectonics and geology. The priority goal is to develop a realistic seismotectonic model and to evaluate the reactivation potential of all faulted structures identified under the action of a particular stress field defined by the stress tensor, SHmax orientation and tectonic regime.
... Fig. 1 -a) Seismological and tectonic features of the South Carpathians [11,12]. Seismicity after [13,14] and this study. b) Profile 1-1' ...
... For the epicentral distance De = 142 km to Berzovia calculated with the new epicenter results the intensity, Io = IX 0 MSK, Ms = 6.0 [33] and h_instr = 18.9 km we obtain intensity I = V-VI 0 MSK. For the Timisoara location (De = 112 km) results Ii computed = V-VI 0 MSK, a value comparable to that in his catalogue [14] where Iobs = V 0 MSK. The same result is obtained for the earthquake of 12.08.1924 ...
The paper presents a seismotectonic model of the Southern Carpathians obtained from the analysis of the seismicity-stress field-geology and tectonics relationship. The seismicity model is based on a revised earthquake catalogue. The distribution of b-values in the 3D space facilitated the identification of stressed areas and asperities with reactivation potential and their correlation with geological structures. The stress field has been modelled using the parameters of the stress tensor calculated by the formal inversion of the focal mechanisms. The reactivation potential of geological structures was estimated depending on the relationship between the fault planes geometry and the principal stress axes.
... Only a couple events with magnitudes larger than 6 Mw were recorded in the historical catalog. Two large events with magnitude of 5.6 and 6.4 Mw and with observed macroseismic intensity I of VIII-IX EMS were reported in this region [9][10]. ...
In this study, we investigate how the recorded seismic ground
motion is influenced by the local/regional geological structure for sites located in the centre and western Romania. The Horizontal-to-Vertical Spectral Ratio (HVSR) technique was applied for 3.1–5.7 Mw events, to extract characteristics of the seismic wavefield and to evaluate the predominant frequency of resonance (fpred). The amplitudes of the HVSR curves computed for the events located along the Carpathian arc are strongly reduced by back-arc attenuation while no effects were observed for the others. The fpred matches relatively well the fundamental frequency at sites deployed on a superficial layer of sediments while a migration to higher frequencies were observed for complex sedimentary structures.
... The western part of Romania is the second seismic area of the country regarding the seismic intensity [13] but is mainly influenced by rather shallow earthquakes, which are only producing significant damage starting with 8 kilometres around the epicentre [14]. 94 seismic events with a seismic intensity between V and VIII on the Mercalli scale were recorded in the region [15,16]. ...
... Thus, it can be seen from Fig. 1b: 1) clusters associated with the seismic sequences from July-August 1991 and from 1998-1999 located on CJFS, with a main shocks on 18.07.1991 (M w =5.7) and 10.01.1998 (M w = 3.9), respectively [2,10]; 2) clusters from the Caransebes-Mehadia Depression produced WNW-ESE alignments during 31. 10.2014-20.02.2015, 23.11.2015-28. ...
... 10.2014-20.02.2015, 23.11.2015-28. 12.2015 and 27.07.2016-28.08.2016 [6]; 3) clusters on OMNFS [1,2,3]. The strongest earthquakes occurred at Moldova Noua (10.10.1879, ...
... M w = 5.3 and 18.07.1991, M w = 5.7) [1,2,10]. The maximum horizontal stress (Shmax) in the region has NE general direction and the tectonic regime vary from extensive in the West to transtensive in the East and transpresive in the NE [3,7,10,17]. ...
We present the study of the earthquakes sequence from 25 June to 6 July 2020 occurred in the western South Carpathians. The main shock had Io= VMSK, Mw= 4.1, occurred at h= 16 km, was preceded by a foreshock (Mw= 3.2) and has 16 after-shocks (Mw= 1.6–4.1) concentrated in the depth range 14–21 km. The focal mechanisms are characterized by strike-slip faults and P axes oriented N76E. The causative fault is dextral strike-slip oriented NE-SW, known as Cerna–Jiu Fault. The macroseismic data partially match the intensities attenuation and conversion accelerationintensity relationships.
... The seismic region is located in the western and southwestern part of the country, with five distinctive area of high seismic potential, such as Banloc, Herculane, Moldova Noua, Voiteg and Sag-Parta [183]. The registrations illustrate earthquakes with magnitudes ranging between 0.2 MW and 5.6 MW [186]. A detailed map, with the surroundings of Timisoara is illustrated in Figure 3.36. ...
... As previously presented, in the area of Timisoara, there were registered earthquakes with magnitudes between MW = 0.2 ÷5.6 [186] and the peak ground acceleration is considered to be ag = 0.20g in Timisoara city and ag = 0.25g in Banloc area, according to the Romanian design code [179]. ...
Doctoral thesis in the field of seismic vulnerability assessment of historical urban centers
