Eugen Oros

National Institute for Earth Physics · Laboratory of Seismological Research

Articol publicat in revista Academiei Romaniei, Institutul de Geodinamica Saba S Stefanescu, Studii si Cercetari de Geofizica

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 seis...

We present a study of the strongest historical earthquakes (Mw > 5.0) occurred in West Romania between 1900 and 1980 conducted to review and homogenize the Romanian Earthquakes and Focal Mechanisms Catalogues on instrumental data basis. New hypocenters relocation, moment magnitudes, Mw and focal mechanisms solutions are obtained on historical instr...

A collection of 431 historical seismograms obtained from 4 Romanian seismic stations (TIM, SSR, GZR, BZS) that recorded the strongest Euro-Mediterranean earthquakes is presented. These seismograms were scanned by the SISMOS Group of INGV Rome as part of the EUROSEISMOS 2002-2007 Project supported by the European Seismological Commission. They are a...

A digital waveform collection from analog seismograms scanned within the EUROSEISMOS 2002-2007 Project is presented. These are recordings of the strongest historical earthquakes produced in the western part of Romania where Romania's most important seismotectonic risk zone with crustal earthquakes is located. Romania was an active partner throughou...

The seismograms are obtained as part of the collaborations carried out through the participation of the main author, Eugen Oros, as a representative from Romania in the EUROSEISMOS 2002-2007 project of the European Seismological Commission. The participation situation is highlighted in the following links: https://storing.ingv.it/es_web/Data/Collec...

The database contains macroseismic intensities obtained for two groups of earthquakes used for the calibration of the Bakun-Wentworth method of localization and estimation of the Mw magnitude using macroseismic data, respectively the group of earthquakes used to calibrate the attenuation relationship and the group of earthquakes used for its valida...

We present a refined and the most complete catalogue of the focal mechanisms for the Intra-Carpathian region of Romania. It contains the high-quality solutions computed for 1217 earthquakes recorded between 1909 and 2018. Primary data gathered from the original seismograms and seismic bulletins have been used to compute the source parameters and fo...

The Catalogue is a compilation containing 1299 events (Mw≥3.0) that occurred between 08.01.1223 and 31.12.1989 within the Intra-Carpathians Region of Romania. It can be accessed and downloaded at: Mendeley Data, doi: 10.17632/p8rgkfhjbz.2 The focal parameters of imported earthquakes have been revised using all primary data collected from the ava...

Text integral (full text) online pe site-ul editurii: http://lectura.bibliotecadigitala.ro/?s=Cercet%C4%83ri+privind+hazardul+seismic+pentru+Banat Si in "librăriascriitorilor.ro": http://librariascriitorilor.ro/Lectura/Cercetari%20privind%20hazardul%20seismic%20pentru%20Banat/index.html

This database was published in two papers: 1. E. OROS, M. POPA, I. A. MOLDOVAN (2008). SEISMOLOGICAL DATABASE FOR BANAT SEISMIC REGION (ROMANIA) - PART 1: THE PARAMETRIC EARTHQUAKE CATALOG. Romanian Journal of Physics 53 (7-8): 955-964 2. E. OROS, M. POPA, E. POPESCU, I. A. MOLDOVAN (2008). SEISMOLOGICAL DATABASE FOR BANAT SEISMIC REGION (ROMANIA)...

Tectonic stresses in the lithosphere are the key to understanding geodynamic processes in general and seismogenesis in particular, being observed during their release by tectonic earthquakes. The relationships of the stress field with tectonics and the structure of the upper lithosphere are complex and controlled by both regional and local factors....

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 assess...

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...

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 reactiv...

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-sli...

The paper represents a multidisciplinary investigation of the relation between seismicity, active stress field and geological structure for the West of Romania. The study is based on revised and updated catalogues of earthquakes (3572 events) and focal mechanisms (89 solutions). The large spatio-temporal variations of the stress tensor parameters,...

In this paper, we have studied the seismic activity in relation with geology, and tectonics in order to highlight seismogenic processes recorded in Danubian area and Hateg-Strei Basin. The Danubian seismogene area presents a complex geological structure, being characterized by the following tectonic units: Median Dacides (Getic and Supra-Getic napp...

The purpose of the present study is to elaborate a new model of the macroseismic intensity attenuation using all observed intensities data for the crustal earthquakes in Romania and then, based on this relationship, to calibrate the Bakun-Wentworth method, one of the modern methods most used to estimate the parameters of the historical earthquakes...

Intra-Carpathian Region of Romania experienced strong earthquakes as it is mentioned in the national and international databases, e.g. November 26, 1829 (Ms = 6.4), October 10, 1834 (Ms = 6.3), January 26, 1916 (Ms = 6.4), July 12, 1991 (Mw = 5.7). The paper focuses on calibration and validation of MEEP method (Macroseismic Estimation of Earthquake...

Active tectonic deformation is continuously shaping the landscape in the Alpine Orogenic system. Earthquakes are clear proves of neotectonic deformation process. In the Romanian Carpathians the most active deformation is recorded in the South Eastern Carpathian Bend Zone. Nevertheless, seismicity associated to latest orogenic stage of active deform...

The paper presents a detailed analysis of the seismic activity recorded in the Banloc-Voiteg seismogenic structure (Romania) located on the southeastern border of the Pannonian Depression which is characterized by pre-Alpine and Alpine structures belonging to Tisa-Dacia Microplate and, particularly by the tectonic contact between two main geodynami...

The study region is the most important seismic region of Romania when we refer to the crustal seismicity as a source of seismic hazard. So far there have been recorded 91 seismic events that produced significant effect in buildings (Io ≥ 6 EMS), some of them resulting in severe damage and even casualties (Io ≥ 7 EMS). In this paper we modelled the...

The main task of the presented study is to elaborate a set of relations of mutual conversion macroseismic intensity - magnitude, necessary for the calibration of the historical crustal earthquakes produced in the Intra - Carpathian region of Romania, as a prerequisite for homogenization of the parametric catalogue of Romanian earthquakes. To achiev...

The inner part of the Carpathians in Romania belongs to the Carpathians-Pannonian system bordered by the Eastern Carpathians to the north and east, Southern Carpathians to the south and Pannonian Basin to the west. It is a complex tectonic region with differential folding mechanisms, post-collisional kinematics, rheology and thermal properties, inc...

The paper highlights the seismicity of the Strei-Hateg depressionary system. This system is situated in the western part of the Southern Carpathians, and consists of two intermountain, post orogenic basins, Hateg basin and Strei basin. These two basins are separated by a threshold. The seismicity is characterized by moderate magnitude with a maximu...

The active stress pattern in the Apuseni Mts area is investigated and studied in relation to the local seismicity and geology. Our analysis is based on several high quality and resolution data bases obtained recently in the context of national and international projects and which refers to digital seismograms recorded by dense networks, parametric...

The active stress pattern in the Apuseni Mts area is investigated and studied in relation to the local seismicity and geology. Our analysis is based on several high quality and resolution data bases obtained recently in the context of national and international projects and which refers to digital seismograms recorded by dense networks, parametric...

The Romanian Intra-Carpathian Region is located on the eastern half of Tisa-Dacia geodynamic block from the Neogene Carpathian-Pannonian Basin. The distribution of seismicity displays clear clusters and narrower zones with seismogenic potential confirmed by the damaging earthquakes recoded in the region, e.g. July 01, 1829 (Mw=6.2), October 10, 183...

Romania has a long tradition in observing, recording and studying historical earthquakes using both the macroseismic methods and instrumental techniques. Beginning with the first instruments mounted in Bucharest by Hepites in 1895 (Tacchini Guzzanti micro-seismoscope and a Tacchini pendulum) a large number of stations and seismological observatorie...

We propose to investigate the local seismic events in the western part of Romania using data from the SCP experiment, a joint project between University of Leeds, UK and National Institute for Earth Physics, Romania (South Carpathian Project – SCP), using 33 broadband seismic stations autonomously that operated in the western part of the country an...

An earthquake swarm of 940 events with ML magnitude between 0.1 and 4.0 and the depth no more than 25 km occurred during three months in the SouthEastern Carpathians foredeep, in an area of around 200 km2, at 27 km northeast of the Galati city. JHD relocation highlights a rupture area steeply dipping down to 15 km depth along a NE­SW alignment. Alt...

An earthquake swarm of 940 events with ML magnitude between 0.1 and 4.0 and the depth no more than 25 km occurred during three months in the South-Eastern Carpathians foredeep, in an area of around 200 km2, at 27 km north-east of the Galati city. JHD relocation highlights a rupture area steeply dipping down to 15 km depth along a NE-SW alignment. A...

The macroseismic effects of three major events recorded in historical time (1738, 1802, 1838) are re-evaluated and compared with three major events recorded in the 20th century in the Vrancea subcrustal source (1940, 1977, 1986). The purpose of the paper is to detect characteristic resemblances and differences in the macroseismic distributions amon...

The Earthquake Catalogues (EqC) represent the most important product of the Observational Seismology. To reflect as good as possible the seismicity and seismotectonics and to be an available database for the seismic hazard studies, the Earthquake Catalogues have to be representative, complete and homogenous. These databases have a number of peculia...

The Vrancea major earthquake of 10 November 1940 (Mw 7.7) is the largest instrumentally recorded earthquake in Romania. It was preceded and followed by several months of enhanced seismicity with several events of magnitude above 5 and 6. The largest preshock (Mw 6.5) occurred on 22 October 1940, while the largest aftershock (Mw 5.9) occurred one da...

As a result of the deployment of the permanent Romanian broadband stations in the last 10 years, valuable data for seismicity and crustal structure studies in Romania has become available. Complementary to this dataset, during a joint project between University of Leeds, UK and National Institute for Earth Physics, Romania (South Carpathian Project...

The present day seismic activity from a region reflects the active tectonics and can confirm the seismic potential of the seismogenic sources as they are modelled using the historical seismicity. This paper makes a comparative analysis of the last decade seismicity recorded in the Banat Seismic Region (western part of Romania) and the historical se...

The paper makes a comparative analysis of recent seismicity (last decade) recorded in Banat Seismic Region (western part of Romania) and the historical seismicity of the region (Mw≥4.0). Four significant earthquake sequences have been, recently localized in the region, three of them nearby city of Timisoara (2012 and 2013) and fourth within Hateg B...

We analyze the seismic activity recorded between January and March 2012 near the city of Timisoara. We identified two earthquake sequences during this time interval: one started on 07.01.2012 at a few kilometers SW of the city (N = 3 events, Depic = 1-7 km, Mwmin = 2.1, Mwmax = 3.1, hmin = 7.1±1.6 km, hmax = 9.8±1.0 km), the other with the main eve...

Timişoara city area develops within Banat Seismic Region, the most crustal seismic active regions of Romania (focal depths less then 30 km). The city of Timişoara and its neighbouring localities historically experienced more strong earthquakes (Mw>=5.4). The seismicity is characterized by groups of epicenters well correlated with a complex geologic...

Prezentarea tezei de doctorat

We determine crust and upper mantle structure in the western part of Romania using regional seismicity recorded on a combined temporary and permanent network (station spacing ∼ 50 km). The area is characterized by shallow seismic activity of moderate magnitude (ML < 6) with frequent clusters of events. Tectonically, the region is divided into block...

The main goal of this study is to investigate the crustal structure in the western part of Romania, in Banat seismic area. The seismicity in this area is characterized by shallow activity of moderate magnitude (magnitude below 6) with frequent multiple sequences. The region is divided in many tectonic blocks bordered by intracrustal faults and with...

Macroseismic intensities (EMS98), instrumental moment magnitude, Mw and hypocenter locations of eleven crustal earthquakes (4.0≤Mw≤5.6) were used to calibrate a new macroseismic intensity attenuation model for the Western part of Romania (South-Eastern Border Of Pannonian Depression). Using data obtained for seven well located local earthquakes (4....

The paper is a synthesis of the newest results of the seismological researches obtained for the western part of Romania using new data bases. The western part of Romania (often called Banat Seismic Region, BSR) is the most important crustal seismogenic zone of Romania. The newest Earthquake Catalogue comprises more than 8000 entries with magnitude...

Local seismic hazard sources for the western and south-western territory of Romania (usually called as Banat Seismic Region, BSR) are localized and characterized using new data and information about the local seismicity and seismotectonics. Using the most recent and comprehensive Parametric Earthquake (over 8000 entries, 0.4<M<5.7, 2.0<h<35 km) and...

The investigation of the site-effects using spectral ratio methods in the city of Timisoara is presented. A non-reference-site technique, often called Nakamura's method is used to determine the resonance frequencies, fr, of the uppermost sedimentary layers. The method was applied on i) seismic noise time-series (HVSRN); ii) earthquakes waveforms re...

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 modi...

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, 1...

The western part of Romania, where the most important crustal seismogenic zone is lying, experienced last two centuries many damaging local earthquakes (M>5.0). The following types of sequences were identified: MS-type (main shock-aftershocks), FMA-type (foreshock(s)-main shock-aftershocks) and S-type (swarms). Many events also occurred solely. The...

The main purpose of the paper is to offer an overview of the situation existing in Banat county, regarding crustal deformation and propose solutions for future monitoring. Taking into consideration the history of the field movements in this area, causes, intensity, propagation, it would be interesting to establish a permanent solution for their eva...

The seismicity of the western and southwestern territory of Romania, called in this paper Banat Seismic Region (BSR) is analyzed for the historical period using a new regional Parameter Earthquakes Catalogue (Oros et al. 2007). The catalogue comprises a number of 709 earthquakes occurred between 1443 and 1970, the 269 of which being new recorded ev...

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,...

Historical earthquakes data represent a wealth of potential information on long time seismicity. Its knowledge has crucial significance for any detailed study of seismicity, seismotetconics and hazard assessment. The first information about the earthquakes occurred in the western-southwestern part of Romania, also called Banat Seismic Region (BSR)...

The main goal of this posterr is rating all dams from Banat region - western part of Romania into seismic risk classes. Dam owners and regulators must ensure that dams are safely operated and present no risk to the public in case of an earthquake. While most old or new dams in recognized seismic regions have been evaluated and analyzed for seismic...

The paper is a contribution to EUROSEISMOS project that begun two years ago, at ESC2002 in Genoa. Ioan Curea was a famous Professor at Cluj and Timisoara universities and a devoted scientist with significant results on mathematic, astronomic and seismologic topics. He founded and managed the Cluj and Timisoara seismic stations and he organized the...

The seismicity of the Banat Seismic Region (BSR) is analyzed in this paper based on a recent comprehensive database (Regional Earthquake Catalog, REC) cataloging 890 seismic events occurred between 1444 and 2006 (I≥V MSK / Mw3.0). The catalog has two different main parts: i) the macroseismic catalog (242 events occurred between 1444 and 1979, I≥V M...

Profesorul Ioan Curea reprezintă pentru Seismologia românească şi europeană un nume de referinţă. Principalele sale realizări constau, în primul rând, în construcţia unor importante staţii seismice performante, care au jucat un rol relevant în dezvoltarea cercetării seismologice la nivel naţional şi internaţional (Radu 1997, Radu şi Toro, 1997). St...

The state of the art on the several earthquakes that affected the western Romania during the first part of the last century is mainly based from macroseismic data with very uncertain intensity data points. Sometimes magnitude and epicentral coordinates have been obtained from historical catalogs (e. g. Karnik, 1968; Radu, 1974). The main events tha...

Ioan Curea (1901-1977), mathematician and Honored Professor at Cluj and Timisoara universities, has dedicated a long part of his life to Seismology. Knowing the history of the seismic instrumental observations made at the beginning of the XX century in Timisoara and Cluj (1901-1919), Ioan Curea succeeded, in spite of the difficulties, to re-establi...

One of the first problems which must be solved by geo-scientific communities refers at natural hazard. There are a number of methods for seismic hazard assessment. Deterministic seismic hazard is the first method to go beyond observations of effects and look at the causes of seismicity. The first stage in the method is to find the nearest active fa...

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...

The seismic hazard assessment in dense ­populated areas and the strategic objectives design are based on the study of seismicity of the seismic sources (which can have an effect at the site above a specified minimum level that is considered risky) and the attenuation between focus and site. The purpose of this paper is to provide a complete set of...

Detection of precursory phenomena is essential for earthquake prediction purposes. The coseismic signals are also useful for clarifying the mechanism of these phenomena. The variations of some geochemical parameters obtained from three mineral water wells from Buzias Spa (HCO3, CO2 dissolved, Fe), their temperatures and flows are all correlated wit...

The "TIMISOARA SEISMIC STATION" was founded on 15.11.1942. "De facto" it is the descendent of the Seismological Observatory developed at the end of the XIX century and the beginning of the XX century under the Austrian-Hungarian administration. Since 1977, the TIMISOARA SEISMOLOGICAL OBSERVATORY belongs to the National Institute for Earth Physics R...

Timisoara is a great Romanian town (about four thousands people) placed in the Western Plain of Romania, on the southeastern border of Pannonian Basin. The seismicity of the region is moderate, with strong but rare earthquakes (Mmax = 6.5, Imax observed = 9 MSK degrees - for 1440 ­ 2001 period). For Timisoara city, maximum expected intensity is 7.5...

The paper presents some results of the seismological research of the Western Zone of Romania (WZR), one of the most active seismic regions of the country. For 984 - present day period, 65 earthquakes with Imax.obs >= VI MSK degree are documented. On the seismicity basis the hazard seismic sources from WZR - historical and contemporary confirmed - a...

The paper presents the main characteristics of the earthquakes occurred in the Banat Seismic Region of Romania between 1766-2000, that have significant impact on the seismic hazard assessment. The most important features are emphasized: i) the spatial and time distribution of the epicenters and the regional seismotectonics, ii) the temporal evoluti...

It is presented a Visual Basic program which allows the quickly determination of the main parameters for a near earthquake (dist.<1000 km): origin time, geographical coordinates, focal depth, magnitude and epicentral intensity (Io). The program allows easely the insert and the change of the input data (seismic waves, travel times, seismic stations...

The seismicity of the West part of Romanian territory is analysed in the paper. The crystalline bedrock bottom of the old Pannonian hollow, the variable and small thickness of the sediment layer, the actual tectonic movement of the crust are involved for the current shallow quakes that occur in the region. The energetic assessment, the frequency co...

The paper presents a well documented seismotectonic map for the western territory of Romania, named as Banat Seismic Region (Banat and Danube Seismogenic Zones). The map was constructed using a modern smoothed seismicity model and its correlation with tectonic and geology (faults, nappes, neotectonic structures like grabens and highs). The seismic...

This work answers to many questions requested by people who experienced the 1991 earthquake crisis from Banat (Romania, West territory): 1. What are the earthquakes, why, where and when they can occure? 2. Can be predicted the earthqaukes? 3. The earthqaukes occurred in the Banat Plain of Romania 4.Geological structure if the Banat Plain of Romania...

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Berriasian-Valanginian deposits which crop out south of Ilidia, on the western border of the central part of the Resita zone, are characterized by the presence of frequent intercalations of allodapic limestones. Microfacial study of theses intercalations pointed out the existence of some interesting micropaleontological associations. Besides microf...