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Copyright of Revista de Silvicultură şi Cinegetică is the property of Societatea Progresul Silvic / Forest Progress Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This short paper focuses on the evaluation of the ground motions levels likely experienced in ten cities seriously damaged during the November 1940 intermediate-depth Vrancea (Romania) earthquake ( M = 7.7). In the first step of the analysis, the ground motion levels are evaluated using a recently developed ground motion model (Vacareanu et al. in J Earthq Eng 19(3):535-562, ) for the Vrancea intermediate-depth seismic source. Next, the stochastic method of simulation (Boore in Pure App Geophys 160:635-676, ) is employed in the same purpose. In order to include the nonlinear soil effects into the results of the stochastic simulations, a dedicated amplification function is derived from the ground motions recorded during two large magnitude Vrancea earthquakes in 1986 and 1990. The results obtained for the November 1940 Vrancea earthquake show that the largest spectral ordinates are obtained when the nonlinear soil effects are taken into consideration, while the peak ground accelerations are in almost all cases in excess of 0.15 g. In addition, the results for Bucharest are validated through a site-specific response analysis performed using a soil profile from the literature. This site response analysis for the 1940 seismic event reveals long-period spectral amplitudes, similar to the ones observed in Bucharest during the Vrancea 1977 earthquake. [ABSTRACT FROM AUTHOR]

The Vrancea subcrustal seismic source is characterized by large magnitude ( $$M_{W} \ge 7$$ M W ≥ 7 ) intermediate-depth earthquakes that occur two or three times during a century on average. In this study several procedures are used to grade four candidate ground motion prediction equations proposed for Vrancea source in the SHARE project. In the work of Delavaud et al. (J Seismol 16(3):451–473, 2012 ) four ground motion prediction models developed for subduction zones (Zhao et al. in Bull Seism Soc Am 96(3):898–913, 2006 ; Atkinson and Boore in Bull Seism Soc Am 93(4):1703–1729, 2003 ; Youngs et al. in Seism Res Lett 68(1):58–73, 1997 ; Lin and Lee in Bull Seism Soc Am 98(1):220–240, 2008 ) are suggested as suitable for Vrancea subcrustal seismic source. The paper presents the appropriateness analysis of the four suggested ground motion prediction equations done using a dataset of 109 triaxial accelerograms recorded during seven Vrancea seismic events with moment magnitude $$M_{W}$$ M W between 5.4 and 7.4, occurred in the past 35 years. The strong ground motions were recorded in Romania, as well as in Bulgaria, Republic of Moldova and Serbia. Based on the ground motion dataset several goodness-of-fit measures are used in order to quantify how well the selected models match with the recorded data. The compatibility of the four ground motion prediction models with respect to magnitude scaling and distance scaling implied by strong ground motion dataset is investigated as well. The analyses show that the Youngs et al. (Seism Res Lett 68(1):58–73, 1997 ) and Zhao et al. (Bull Seism Soc Am 96(3):898–913, 2006 ) ground motion prediction models have a better fit with the data and can be candidate models for Probabilistic Seismic Hazard Assessment. [ABSTRACT FROM AUTHOR]

Due to the subcrustal earthquakes located at the sharp bend of the Southeast Carpathians, Vrancea zone in Romania has a high potential seismic hazard in Europe. Among several seismic precursors, radon anomalies in air, ground, and groundwater in the epicentral areas can be associated with the strain stress changes that occurred before and after earthquakes. In order to support this theoretical view, the main aim of this paper was to investigate temporal variations of radon concentration levels in air near the ground and in ground air by the use of solid state nuclear track detectors CR-39 and LR-115 in relation with some seismic events at two seismic stations Vrancioaia and Plostina, located in Vrancea active region. This paper reports essentially the observation of radon concentration levels in the air near the ground at 1 m height for the earthquakes that occurred during the period of November 2010-October 2011 and moment magnitudes M in the range of $$ 2.0 \le M_{\text{w}} \le 4.9 $$. The average radon concentration in air above the ground measured with CR-39 detectors recorded for 1 year period in Vrancea area was 1,094.58 ± 150.3 Bq/m and 10 days fluctuations were placed in the range of 129 ± 40 Bq/m and 5,888 ± 700 Bq/m. Also have been reported measurements of in soil radon concentrations in drill holes at 0.5 m depths during period of March 1977-October 1980, just after 4 March 1977, M 7.4 Vrancea earthquake. The knowledge of air-ground-gas Rn anomalies is very important for earthquake pre-signals assessment as well as for precisely location of geologic active faults. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Polytechnic Institute of Iasi - Construction & Architecture Section is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

If we follow the opinions expressed by the most recent studies and concerns in the field, but also our own observations accumulated during our career, we find that in the last two decades the geomorphological mapping as a scientific discipline came under a shadow cone. The reasons are several, but we selected two in particular: (1) the geomorphological mapping is an expensive and time-consuming activity and (2) the geomorphological mapping has focused more on themes and applications than on complex maps with a holistic approach. It is surprising that the decline of the geomorphological mapping coincides with the powerful development of GIS techniques; the geomorphological maps based on the traditional mapping began to be overlooked in exchange for opportunities to combine with the GIS database. In this paper we propose to draw attention to the fact that by neglecting the mapping of the lanforms it happened to arrive to mediocre mapping achievements pompously titled geomorphological maps. Even if the maps are using the traditional method of symbolic representation of landforms, or software of the GIS platform, the result shows that there isn't a knowledge of the methodological norms for the preparation of geomorphological maps. We usually learn them during the university training. We have several examples in this regard. In the second part of the work we plan to offer a model of geomorphological mapping using the modern techniques we have today, but with a very careful observance of the criteria for mapping the landforms. We will try to give an answer to the question whether the GIS software platform is feasible for constructing a general geomorphological map. For this we will present a practical application on a sector of the Putna valley from Vrancea county. The final comments and discussions on applications will help in finding the most appropriate graphic expression of the distribution of landforms, so that the geomorphological mapping could be widely used by young researchers. [ABSTRACT FROM AUTHOR]

In Romania there is one of most powerful seismic activity region from Europe, known as Vrancea. In the past 300 years, a single major seismic event occurred with an epicenter outside this area (1916). This paper starts from going over all major seismic events, with a magnitude of over 6 degrees on Richter's scale, which were documented. Was tested the most plausible statistic behavioral model and was determined the probabilities for future large scale earthquakes, by different time horizons. [ABSTRACT FROM AUTHOR]

The paper is intended to summarize the most important instrumental data of direct relevance for engineering activities, obtained in connection with the strong Vrancea earthquakes of 4 March 1977, 30 August 1986, 30 May 1990, and 31 May 1990, and to point out some significant consequences and conclusions derived on this basis. Two main objectives of this analysis may be emphasized: (a) in-depth analysis of the radiation pattern; and (b) analysis of the spectral contents of ground motion in connection with the features of local conditions, and with the intention of assessing the relative importance of two main factors: source mechanism and long-distance wave propagation, versus features of local geological conditions. Some specific methodological developments used in this context may be mentioned: (a) use of a new approach to the quantification of ground motion intensity on the basis of instrumental (accelerographic) information; (b) analysis of radiation pattern in spectral and directivity terms; (c) parametric analysis of site-specific transfer functions for the local sequences of geological layers; and (d) a critical view on the outcome of post-earthquake survey techniques, keeping in view the implications of the spectral features of ground motion. The main results obtained are related to: (a) ground motion radiation features that have to be taken into account in connection with the data on the source mechanisms of the successive events dealt with; (b) expected spectral features of future strong ground motion at different sites; (c) methodological developments proposed for the assessment of local transfer functions; and (d) implications for microzonation activities. [ABSTRACT FROM AUTHOR]

Abstract: The Vrancea region of the southeastern Carpathians is one of the most active seismic zones in Europe and it is well-known for its strong intermediate depth earthquakes. Seismic tomography had revealed a high-velocity body beneath Vrancea and the Moesian platform that extends to a depth of at least 350 km and can be interpreted as descending lithosphere. The strong earthquakes occur within the northeastern part of this high-velocity body, in a very limited seismogenic volume at intermediate depth (70–180 km). Several geodynamic models have been proposed for this area. They can be split into two main categories, in terms of the nature of the high-velocity anomaly, which may (a) be associated with descending relic oceanic lithosphere beneath the bending zone of the SE-Carpathians, either attached or already detached from the continental crust; or (b) it may represent continental lithosphere that has been delaminated, after continental collision and orogenic thickening. Based on currently available information, it appears difficult to distinguish between these two types of models. In this paper we attempt to shed more light on the nature of the seismic anomaly, as well as that of the origin of the intermediate depth seismicity in the Vrancea zone, by investigating the waveform character of P-waves excited by local earthquakes beneath this area, and in particular the dependence of group arrival times on frequency. We present observations of such a dispersion from stations situated at the bending zone of the SE-Carpathians. On the other hand, signals from the same earthquakes, but observed at reference stations outside of the anomalous zone do not show that frequency dependence. A natural explanation for these observations is that it is caused by the presence of a low-velocity channel at the top of the seismic anomaly, which is too thin to be resolved by classical seismic tomographic techniques. Similar observations of dispersed first-arriving P-waves have been made above subduction zones around the world, in which low-velocity layers with a thickness of several kilometers are known to exist. This suggests that a tabular slab of subducted oceanic crust is present within the seismic anomaly under the Vrancea region, and that the anomaly consists of subducted oceanic lithosphere rather than continental lithosphere, at least at depths shallower than the seismically active zone. [Copyright &y& Elsevier]

On October 27, 2004, a moderate size earthquake occurred in the Vrancea seismogenic region (Romania). The Vrancea seismic zone is an area of concentrated seismicity at intermediate depths beneath the bending area of the southeastern Carpathians. The 2004 M = 6 Vrancea subcrustal earthquake is the largest seismic event recorded in Romania since the 1990 earthquakes. With a maximum macroseismic intensity of VII Medvedev-Sponheuer-Kárník (MSK-64) scale, the seismic event was felt to a distance of 600 km from the epicentre. This earthquake caused no serious damage and human injuries. The main purpose of this paper is to present the macroseismic map of the earthquake based on the MSK-64 intensity scale. After the evaluation of the macroseismic effects of this earthquake, an intensity dataset has been obtained for 475 sites in the Romanian territory. Also, the maximum horizontal accelerations recorded in the area by the K2 network are compared to the intensity values. [ABSTRACT FROM AUTHOR]

This paper is focused on a specific methodology able to emphasize the correlation between anomalous behaviour of electromagnetic normalized functions and intermediate depth seismic events which have occurred in the Vrancea zone and pointing out the main constraints related to them. The lithospheric conductivity changes produced prior to and during an earthquake, as a sequence of the dehydration of the rocks, associated with rupturing processes and fluid migration through faulting systems developed inside and close vicinity to foci, could be detected by means of the peculiar features of the electromagnetic normalized functions taken throughout the frequency range DC-10-2 Hz. Some experiments have been dedicated to assess the robustness of a methodology using electromagnetic data acquired over a span of several years. It means that the real-time selected electromagnetic normalized functions complying with temporal invariability criterion for a 2D geoelectric structure in non-seismic condition have been analysed taking into consideration just their daily mean distribution versus seismic events recorded simultaneously. As this methodology emphasizes the conductivity changes prior to a seismic event, it becomes an interesting subject for studying anomalous behaviour of electromagnetic normalized functions against their normal variation as possible precursors of earthquakes triggered in the Vrancea zone. [ABSTRACT FROM AUTHOR]

Consumers, regulators, and the food industry increasingly require that foods comply not only with the label descriptions of food content, but also with information regarding the food origin. For example, the wine industry has a long history of labelling wines based on varietal, regional, or age (vintage) - related properties. However, regulatory agencies are now beginning to require methods to confirm this label information. Wine retailers are also facing voluntary or mandatory labelling requirements that will indicate regional or country-of-origin, species and/or varietal information. As a result, development of reliable analytical methods to confirm the authenticity of the label information is needed. The adulteration of wine is usually accomplished by addition of alcohol, water, dyes and aromas to wine of minor commercial value. As these wines are usually produced with inadequate conditions of hygiene, they become of high risk for the human health. Another risk for the consumer of adulterated wines is the ingestion of products elaborated of raw materials not under control evidence. The aim of this study was to identify the adulterated wines obtained in vineyards of Vrancea County by the private and local producers during the time period of 2006-2008. From the 913 wine samples analysed it was noticed that the cheap wines are frequently adulterated. The trend of wine adulterations from Vrancea County had a decreasing value from 2006 (70.3%) to 2008 (35.1%). The decreasing of the adulterated wines from 2006 to 2008 is probably due to the application of Romanian legislative regulations on wine quality level. [ABSTRACT FROM AUTHOR]

Vrancea, Eastern Romania, presents a significant intermediate-depth seismicity, between 60 and 170 km depth, i.e. pressures from 2 to 6.5 GPa. A debate has been lasting for decades regarding the nature of the seismic volume, which could correspond to the remnant of a subducted slab of Tethyan lithosphere or a delamination of the Carpathians lithosphere. Here we compile the entire seismicity dataset (≈ 10,000 events with 2 ≤ Mw ≤ 7.9) beneath Vrancea for P > 0.55 GPa (> 20 km) since 1940 and estimate the pressure and temperature associated with each hypocenter. We infer the pressure and temperature, respectively, from a depth-pressure conversion and from the most recent tomography-based thermal model. Pressure–temperature diagrams show to what extent these hypocentral conditions match the thermodynamic stability limits for minerals typical of the uppermost mantle, oceanic crust and lower continental crust. The stability limits of lawsonite, chloritoid, serpentine and talc minerals show particularly good correlations. Overall, the destabilization of both mantle and crustal minerals could participate in explaining the observed seismicity, but mantle minerals appear more likely with more convincing correlations. Most hypocentral conditions match relatively well antigorite dehydration between 2 and 4.5 GPa; at higher pressures, the dehydration of the 10-Å phase provides the best fit. We demonstrate that the Vrancea intermediate-depth seismicity is evidence of the current dehydration of an oceanic slab beneath Romania. Our results are consistent with a recent rollback of a W-dipping oceanic slab, whose current location is explained by limited delamination of the continental Moesian lithosphere between the Tethyan suture zone and Vrancea. [ABSTRACT FROM AUTHOR]

On a population of 1520 Brown cows, from 15 farms located in Vrancea County were evaluated the main reproductive indicators on the basis of data from official control in farms. Were evaluated the following indicators: rank of lactation, age at first calving (AFC), serviceperiod (SP), dry period (DP), calving interval (CI)and number of artificial inseminations for one gestation (IA). From analysis of mean values could be observed that average age at first calving was of approximately 33 month ranking between 29 and 35 month, the analysed population having precocity under the standard of Brown breed. Number of inseminations for one gestation was 2.09, at the farms level being recorded a poor management of frozen seminal material. Reproduction indicators had means values which prove that reproduction function was poor technically managed. [ABSTRACT FROM AUTHOR]

Fault plane solutions for earthquakes recorded in Romania (1929–2012) are analysed on three depth levels: crust (0–50 km), upper (50–110 km) and lower segment (110–201 km). For the Vrancea intermediate-depth source reverse faulting is predominant. However, local-scale variations occur at the upper and lower limits of the active volume: normal faulting (upper side) and strike-slip with normal faulting (lower side). These edge effects are probably caused by the interaction of cold descending lithosphere with hot surrounding asthenosphere acting there. Fault plane solutions of crustal earthquakes reflect complicated patterns associated to local stress sources perturbing the regional field. One important result of our analysis is the delimitation of specific active alignments in North Dobrogea Orogen, Bârlad Depression, Danubian and Banat zones, while seismicity is diffuse and close to random distribution in the other seismogenic zones. The polar diagrams for azimuthal and dip angle distributions and the ternary diagrams for P, T and B axes show prevalence of reverse faulting in Vrancea intermediate-depth source, strike-slip in combination with normal faulting in South Carpathians and Banat region and a deficit of strike-slip faulting south-east of Carpathians. Lack of strike-slip component makes us believe that the deformation field is controlled in the Carpathians Foredeep not by transcurrent deformation along the major faults crossing the region, but rather by subsidence and folding processes as stress release mechanisms in the crust in response to the intense tectonic processes beneath Vrancea region. [ABSTRACT FROM AUTHOR]

An inversion scheme using only few good quality high-frequency local waveforms was previously applied to estimate the source mechanism for a pilot set of crustal earthquakes with local magnitudes less than 4, from the bend of the South-eastern Carpathians. Taking advantage of the improved velocity and attenuation models recently determined for the study region, we reevaluate the focal mechanism of a couple of low-magnitude events (local magnitude ≥ 3), and assess the uncertainty of the fault plane solutions. The results evidence the increased reliability of the retrieved mechanisms and emphasize the capability of the approach to provide satisfactorily constrained fault plane solutions for the weak-to-moderate earthquakes in the study region. [ABSTRACT FROM AUTHOR]

We estimated the parameters of strong motion generation areas and simulated broadband ground motions for the moderate October 27, 2004 ( M 5.8) and damaging March 4, 1977 ( M 7.4) Vrancea (Romania) intermediate-depth subduction earthquakes using the empirical Green's function method. The method allows the simulation of ground motions in a broadband frequency range by summing up the subevent records, corresponding to small magnitude events in the near-source areas, which are assumed to follow the source-scaling relationship and the omega-square source spectral model. We first estimated the strong motion generation area that reproduces near-source ground motions in a broadband frequency range of 0.3-10 Hz for the 2004 earthquake, by fitting the synthetic acceleration, velocity, and displacement waveforms to the observed data. The source properties of the obtained strong motion generation area are in agreement with the predictions made using an empirical source scaling relationship for crustal earthquakes, implying a stress drop of approximately 10 MPa for the 2004 earthquake. We then modeled the strong motion generation area for the 1977 damaging earthquake using the 2004 earthquake as an empirical Green's function and constructing a source model based on its estimated source parameters. To simulate the unique record at Bucharest, capital city of Romania, the rupture was assumed to have propagated from the northeast bottom of the strong motion generation area having a stress drop of 50 MPa. Broadband ground motion simulations were further compared in terms of the modified Mercalli intensity values, calculated from the peak ground accelerations and peak ground velocities of synthetic waveforms, with the observed Medvedev-Sponheuer-Karnik intensity values. Our estimates of the source properties for the 2004 and 1977 Vrancea intermediate-depth earthquakes support the size-dependent stress drop. [ABSTRACT FROM AUTHOR]

The structure of tourism movement in Vrancea County during 2011-2015, indicate a low rate of foreigner tourists (5.70%) from the total entrances in the county, number of days/tourist for foreigner tourists have also a low rate (6.41%), and evolution of tourists, foreigners and Romanians, had fluctuations during analysed period The mean level of tourists recorded 39.7338 thousands persons. The mean level of number days/tourist recorded a value of 64.6384 thousands persons. Average duration of the sojourn had also fluctuations during analysed period (2011-2015) being of 1.84 days for Romanian tourists and of 1.61 days for the foreigner ones. Gross utilization rate of touristy accommodation capacity recorded fluctuant values in those 5 analysed years (2011-2015), in 2015 being recorded the highest value 17.54%. From the analysis of touristy movement could be observed an oscillator evolution of dynamic rate for tourists' number, even if per total mean dynamic rate show an increase, in average, with 3.96. Absolute average modification of tourists' number recorded 0.41 thousands persons. Average dynamic rhythm for tourists' number was 296.00%. [ABSTRACT FROM AUTHOR]

The need for evaluation of a sound earthquake disaster mitigation and critical assessment of the detailed cumulative seismic energy dissipated in the Vrancea Region in Romania is required to identify the active seismogenic activity for the last 12 years associated within the seismotectonic zone of Vrancea Region of Romania. The seismogenic behaviour observed by the recent strain energy release from2004 to 2016 in Vrancea by processing the energy bulletin of the seismic energy discontinuity gives new results. Vrancea is the most critical seismo-tectonic region in Eastern Europe prone to earthquakes and suffer seismic energy variations that can be linearly approximated due to the constant rate of earthquake occurrences. This allows to forecast the magnitude using iso-contour plotting and analysis of the energy-magnitude relationship. The study shows that there is an immediate need to diagnose for a unifying slip-dependent law determined from strain energy bearing capacity of the region. In this study, the average moment release rate and strain release pattern within time frame 2004-2016 for the region have been examined by analysing the updated Romplus Catalog from the Vrancea region of Romania. The study shows that if strain energy released by a tectonic block is large it might affect the stress building process in the rocks of adjacent tectonic blocks. Azone of future earthquake activity in the Vrancea based on the study is also identified and an integrated functional block diagrams as part of the activity in any geotectonic region incorporating pre-earthquake parameter assessment is developed. [ABSTRACT FROM AUTHOR]

"Let us begin with the obvious. he Agrarian Question is also the Question of Nature, and, therefore, it is also the Question of Ecological Crises in the modern world" (Moore 2008, 57). But it is not because it is obvious that the ecological dimension of the agrarian question has been omitted in the literature until now. he focus on the political role of peasantry and on the emergence of new class struggles as capitalism made its way in the rural concealed the ecology from 'he Agrarian Question'. his study traces the ecological implications of the development of capitalism in Vrancea region, Romania, from mid-18th century until the present day. It shows that the capitalist transition in the countryside also means a change of socio-ecological relations, namely a change of the social representation of Nature, a change of the modes of appropriating Nature, and a change of the institutions that govern economic action in the natural environment. All these changes are visible in the dynamics of the common property regime in Vrancea as market relations changed in the region. he study concludes that the ecological consequences of an agrarian question can be addressed systematically following the dynamics in the property regimes. Such a systematic analysis can help to better fathom transnational politics for agriculture and their implications for the natural environment in world-wide capitalism. [ABSTRACT FROM AUTHOR]

The August 30, 1986 (MW = 7.1) and May 30, 1990 (MW = 6.9) Vrancea intermediate-depth earthquakes, despite their almost similar magnitudes, have produced very different spectral contents as shown by the strong ground motions recorded in Bucharest and its surroundings. The differences can be attributed to different epicentral distances and to different values of the stress drop. The characteristics of the seismic ground motions recorded in Bucharest area in the 1986 and 1990 seismic events are discussed in the context of (a) the source characteristics of the two earthquakes and (b) the local soil conditions in Bucharest. Furthermore, an attempt is made to determine the soil factorsSdefined in EN 1998-1 for the Bucharest area, based on the strong ground motion dataset recorded during the two seismic events. [ABSTRACT FROM AUTHOR]

A study has been performed on the Cretaceous to Early Miocene succession of the Vrancea Nappe (Outer Carpathians, Romania), based on field reconstruction of the stratigraphic record, mineralogical-petrographic and geochemical analyses. Extra-basinal clastic supply and intra-basinal autochthonous deposits have been differentiated, appearing laterally inter-fingered and/or interbedded. The main clastic petrofacies consist of calcarenites, sub-litharenites, quartzarenites, sub-arkoses, and polygenic conglomerates derived from extra-basinal margins. An alternate internal and external provenance of the different supplies is the result of the paleogeographic re-organization of the basin/margins system due to tectonic activation and exhumation of rising areas. The intra-basinal deposits consist of black shales and siliceous sediments (silexites and cherty beds), evidencing major environmental changes in the Moldavidian Basin. Organic-matter-rich black shales were deposited during anoxic episodes related to sediment starvation and high nutrient influx due to paleogeographic isolation of the basin caused by plate drifting. The black shales display relatively high contents in sub-mature to mature, Type II lipidic organic matter (good oil and gas-prone source rocks) constituting a potentially active petroleum system. The intra-basinal siliceous sediments are related to oxic pelagic or hemipelagic environments under tectonic quiescence conditions although its increase in the Oligocene part of the succession can be correlated with volcanic supplies. The integration of all the data in the 'progressive reorientation of convergence direction' Carpathian model, and their consideration in the framework of a foreland basin, led to propose some constrains on the paleogeographic-geodynamic evolutionary model of the Moldavidian Basin from the Late Cretaceous to the Burdigalian. [ABSTRACT FROM AUTHOR]

The crustal and sub-crustal seismicity that occurred in the Vrancea area from 1978 to 2008 is investigated. Due to quarry blast contamination, the analysis of the crustal seismicity was restricted to events that occurred between 20 km and 60 km, considering sub-crustal events as all those that occurred at depths larger than 60 km. The completeness magnitude was estimated between 2.3 and 2.5 for the crustal seismicity and between 2.9 and 3.1 for the sub-crustal one. The Gutenberg-Richter b-values show clear differences between crustal and sub-crustal seismicity, with values around 0.9 and 1.3--1.4, respectively. The analysis performed in this study represents a preliminary issue for the seismic hazard assessment of surrounding regions like Moldova, for which the earthquakes generated in Vrancea represent an important threat. [ABSTRACT FROM AUTHOR]

The fault plane solutions (FPS) of 247 seismic events were used for stress field investigation of the region. The eigenvectors t,p,b, and moment tensor M components for each FPS were defined and computed numerically. The obtained results confirm the hypothesis of subduction-type intermediate depth earthquakes for the Vrancea seismic region and this may be considered the first approximation of the stress field for the whole of the Vrancea (intermediate depth) region. [ABSTRACT FROM AUTHOR]

The analysis of time-clustering behaviour of the sub-crustal seismicity (depth larger than 60 km) of the Vrancea region has been performed. The time span of the analyzed catalogue is from 1978 to 2008, and only the events with a magnitude of Mw ≥ 3 have been considered. The analysis, carried out on the full and aftershock-depleted catalogues, was performed using the Allan Factor (AF) that allows the identification and quantification of correlated temporal structures in temporal point processes. Our results, whose significance was analysed by means of two methods of generation of surrogate series, reveal the presence of time-clustering behaviour in the temporal distribution of seismicity data of the full catalogue. The analysis performed on the aftershock-depleted catalogue indicates that the time-clustering is associated mainly to the aftershocks generated by the two largest events occurred on 30 August 1986 (Mw =7.1) and 30 May 1990 (Mw =6.9). [ABSTRACT FROM AUTHOR]

A six year-long hydrochemical monitoring operation was conducted in Vrancea seismic zone (Romania), addressing a saline spring that proved to be suitable for Na- K-Mg geothermometry diagnosis. During the considered time-interval (2003-2009), only one important earthquake (mb=5.8) occurred in Vrancea region, this circumstance providing an unambiguous reference-moment between preseismic and post-seismic periods. On occurrence of that earthquake, an anomalous fluctuation of the Na-K temperature was detected - a result largely similar to previous ones recorded worldwide (California, southwest Egypt, northeast India). Yet such fluctuations may not necessarily be induced by earthquake-associated processes: they can occur also "routinely", possibly reflecting some environmental, meteorologically-induced "noise". It was therefore important to examine whether the variations observed in the data values could be plausibly related to a seismogenesis process. By additionally investigating (in a "scattterplot" diagram) the correlation between the Na-K temperatures and the values of a so-called "maturity index", a specific pattern emerged, with pre-seismic data-points plotting in a distinct domain of the diagram; moreover, those data-points appeared to describe a "drift away" pathway with respect to the remaining data-points "cluster", recorded during the subsequent 4 years of post-seismic monitoring. The "drift away" pattern persistently evolved for at least 18 months, ending just before the mb=5.8 earthquake and consequently suggesting the existence of some kind of long-term precursory phenomenon. [ABSTRACT FROM AUTHOR]