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5th Congress of Balkan Geophysical Society
- Conference date: 10 May 2009 - 16 May 2009
- Location: Belgrade, Serbia
- Published: 10 May 2009
81 - 100 of 134 results
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Use PNN tool for revealing and definition of polluting zones on example from Zeitz und Bitterfeld in Germany.
Authors P. Buckup, P. Dietrich and K. BuckupThe pulse-neutron-neutron (PNN) technology offers new perspectives for pollution control. In case studies polluting components of different character are detected and quantified. By mean of several measurements the changings of pollution are monitored real time in control wells under in-situ conditions.
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Seismic magnitude of lithomedia and seismic effect due to blasting explosions
More LessWith „seismic magnitude of lithomedia” is defined the maximal possible (source) amplitude of a monolith from a lithomedium. The generation of seismic effect due to blastic explosions follows the process of „crack-like deformation of the blasted monolith”, with the following regularities: each (monolith of) lithomedia has a „characteristic boundary particule velocity of seismic vibration”, below which there is no plastic deformation and above which there is no elastic transfer of stress waves. The boundary particule velocity of seismic vibration is the strength characteristic of lithomedium. It is not depend from the power of the generator of seismic effect (earthquake, explosition, blows,...), and can be defined in dependance to the lithomedia. Analogously with expression of the destructiveness of hard rocks with blasting, it is also suitable to express the seismic magnitude of a lithomedium in correlation with the seismoacoustic impendance of the blasted lithomedium. With establishment of a „correlative relationship” between seismic magnitudes of lithomedia and acoustic impedances of the sames lithomedia on upgrade the defining and operating with distribution of seismic effect due to blasting.
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Earthquake scenarios: cases study for the cities of Ruse and Vratsa
Authors D. Solakov, S. Simeonova, I. Alexandrova, I. Popova and G. GeorgievaThe present study deals with deterministic seismic scenario generation based on macroseimic intensities, generated by damaging, real earthquakes of the past. The both cities scenarios are representation of the severity of ground shaking over an urban area. The work on scenarios was guided by the perception that usable and realistic ground motion maps had to be produced for urban areas. The differences in local geological and geotechnical characteristics, and urban features of the cities has made it necessary to apply different alternative of the approach sufficiently flexible to account for the basic factors in the different situations. Such scenarios are intended as a basic input for developing detailed earthquake damage scenarios for the cities and can be used in earthquake-safe town and infrastructure planning.
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Influence of Renewable Energy Sources on Community Development, Politics and Aims
By M. PetrovicEndanger of an environment is permanent process that causes far reaching consequences, and at the same time is the generator of economic, sanitarian, psychological and physiological problems of the modern World. Frame of the sustainable development is more modern approach to the consideration of ecological problems. At that, organizations should be dealing with those activities that synchronize nature of the activity with nature laws, all with an aim to preserve natural resources, i.e. environment. Main idea of writing this paper is to stimulate greater use of renewable sources in Serbia (energy potential of over 3,0 M t en per year with potential of small hydroelectric power stations of more than 0,4 M t en) and to highlight importance of sustainable development concept, that would indulge modern needs, in favor of the needs of the future. Application of renewable energy sources reduces use of fossil fuels, and can be very favorable for the reduction of undesirable impacts on the environment. Total energy consumption World wide is over 14 terawatts per year, and from that amount renewable energy sources make 14% of energy supply in the World which is not enough but is necessary condition for sustainable energy development.
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Integrated geophysical investigations in the area of Bulgarian Antactic Base at the Livingston Island
Authors P. Stavrev, N. Krastev, R. Raditchev, V. Stanchev and G. SchwambornResults from geophysical measurements in Hurd Peninsula of Livingston Island are presented along with an analysis and interpretation of the data acquired. The geophysical complex includes electromagnetic sounding (EMs), gravimetry, magnitometry and magnetic gradiometry. These methods are applied in an area between the sea coast and hills around, where metasedimentary complex of the Mауers Bluff formation outcrops, crossed by dykes and in part of the terrain covered by snow and thick ice layer. Useful methodical experience and interesting field data are obtained from the carried out geophysical works. They contribute significantly to a fast distant bedrock mapping and deep geologic structures investigations in the severe Antarctic conditions.
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Schematic map of volcanic centres and intrusive bodies in Eastern Srednogorie and Eastern Rhodopes
Authors A. Tsvetkov and H. TzankovOn the base of integrated geophysical data a scheme of the gravity and magnetic anomalies of the volcanic centres and intrusive bodies in the Srednogorie and Rhodope eastern parts in 1:500 000 scale is created. The outcrops of the magmatic bodies according to the Geological Map of Bulgaria and other data are shown on the scheme. The magmatic bodies for which quantitative interpretation, according to magnetic and gravity data, has been performed are illustrated and the calculated parameters – depths towards upper surface and lower limit or depths towards centre of mass are shown. The geological and geophysical information used for the above-mentioned regions allows a number of volcanic-plutonic, volcanic and plutonic centres and bodies to be determined. Some of these structures, better pronounced in the geophysical fields, are characterized.
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Complex investigation of the recent geodynamics in the region of Krupnik-Kresna
Authors G. Georgieva, I. Radev, I. Popova, E. Mihaylov, G. Marinov, M. Ilieva, K. Matev and M. AtanassovaThe region of Krupnik and Kresna is situated in seismic active part of Bulgaria. The present activity is proved during the earthquake in 1904 and up to now the region is the most active in the territory of Bulgaria. The strongest earthquakes in Europe occurred in April 1904 with magnitude about 7,8. It was preceded from a strong foreshock with magnitude 7,1. In 2006 started a Young Scientist Project “Complex investigation of the recent geodynamics in the region of Krupnik-Kresna”. During the project there were made some seismic and gravimetric measurements in the region.
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Sofia's Palaeomagnetic laboratory achievements in archaeomagnetism
By M. KovachevaThe paper represents the results of longstanding archaeomagnetic studies in the Palaeomagnetic laboratory of Geophysical Institute, BAS. These studies are the only way of discovering the past geomagnetic field behaviour and they play an important role for contemporary geomagnetic field models. Revealing the geomagnetic secular variations and their spatial distribution over the Earth’s globe is also of interest for the dynamics of geomagnetic field. The searched characteristics are: declination (D) and inclination (I) given in degrees and the absolute value of the geomagnetic field intensity F, given in μT. The Bulgarian data set covers mostly fully the last 8000 years and represents the longest set of archaeomagnetic determinations in the world. The accumulation of data is a long process requiring the addition of new sites, revision and refinement. We have sampled also some archaeological sites from former Yugoslavia, the data of which are included in our database. These data are the result of a fruitful collaboration between Geomagnetic Institute in Grocka and the Geophysical Institute in Sofia in the area of paleo- and archaeomagnetism some 40 years ago. The highest achievement of the study is that it is brought to practical application for dating in archaeology. Example is given.
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Spatial variations of seismicity rate precursor to the Erzurum (Turkey) earthquake sequences on March 25 and 28, 2004
More LessWe focused in this study on the detection of seismic quiescence situation prior to the Erzurum (Turkey) earthquake sequences. We used the instrumental catalogue of KOERI from 1970 up to 2005 for the region 38.8º-41.0ºN and 40.2º-43.2ºE. The catalogue includes 1481 crustal events of MD magnitude equal and greater than 2.2, with depths less than 70 km. The completeness magnitude for Erzurum region is 3.0 and the number of events exceeding this magnitude level is 1000. In the first step, we declustered the catalogue using the Reasenberg algorithm. 28 % of the events were removed and the number of these events was reduced to 719. Spatial variation of statistical Z-value is mapped with gridding method at the nodes of a 0.02º grid spacing for every one year between 1995 and 2001 by ZMAP software. We found that the MW=5.5 Erzurum earthquakes on March 25 (at 21:30:50 UTC) and 28 (06:51:09 UTC), 2004 followed an outstanding seismic quiescence with a decrease of the seismicity rate, Zmax=4.0 level at 1999.2, starting 5.04 years before the main shocks near the earthquake regions.
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Aftershock probability evaluation for recent Turkey earthquakes based on Gutenberg-Richter and Modified Omori Formulae
More LessA statistical model of aftershock occurrence probability based on the combination of Gutenberg-Richter and modified Omori formulae is used in this study in order to predict how many large aftershocks should follow small main shocks and in order to evaluate aftershock probability that a randomly chosen earthquake is greater than or equal to a certain magnitude of aftershock. For this purpose, we made an application using eleven aftershock sequences in which occurred Turkey between 2003 and 2005.
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Regional set of dislocations in the Earth's crust of Bulgaria according to gravity data
Authors P. Stavrev, D. Solakov, S. Simeonova and P. TrifonovaRegional set of dislocation in the Earth’s crust is outlined using the magnitude of total horizontal gradient calculated from the new rectified Bouguer gravity grid of 1x1 km along the territory of Bulgaria. The constructed map of steep gradient anomalies serves as a basis in more detailed analysis and interpretation of faults, flexures, thrust and block structures in cooperation with geological, seismological and other geophysical data. Many of these structures cross the state boundaries so a gravity-gradient-map compilation along the territory of Balkans may improve interpretation results in a regional scale.
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Stability Investigations of Rock Slopes in the Sumela Monastery (Maçka-Trabzon, Northeastern Turkey)
Authors K. Gelisli and A.E. BabacanThe Sumela Monastery was established on a cliff at the foots of Karadağ dominating Altındere valley in the county of Maçka in Trabzon, northeastern Turkey. With its great historical and touristic importance, the monastery is visited by approximately 180.000 local and foreign tourists every year. Mass movement on form rock fall occurred in 2001 on the south slope and some social facilities of the monastery and communication roads were damaged. The geological and geotechnical characteristics of the rock slope were investigated and rock fall hazard analyzed. In the rock samples obtained from the study area, uniaxial compressive strength and point load strength were calculated in the laboratory and, by using the scanline survey method in the site, discontinuity and rock mass characteristics were determined. In situ compressional wave velocities were determined by using the seismic refraction method and ultrasonic wave velocities were measured in laboratory on the rock samples. Rock classifications were made, which helped to find the weathering degree, Q index, Rock Quality Designation (RQD) values and Rock Mass Rating System (RMR) values for the Sumela Monastery rock slope.
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Importance of Geovalidation: A Case Study of Choka area (Northern Banat)
Authors D. Radivojevic and R. PesaljIn this paper it will be shown the importance of geovalidation for interpretation of seismic data. The procedure was performed on the territory of Choka (northern Banat). Well shoot surveys were not obtained at any well on Choka area. Synthetic seismogram is done based up on measuring of acoustic log, density log, and borehole velocities obtained from checkshot measurements on well CBj-1. Besides direct evidence of stratigraphy, electric log markers were also used for age determination. Electric log marker X has a very characteristic well log values in all wells. Electric log marker X is a very imposing on the most seismic section and allows very easy tracking in the area. This feature is used for interpretation of Pannonian that in this area is not distinguishable. Pannonian physical properties as well as the manner in which this horizon were interpreted are known as interpretation of "phantom" horizon. Without proceedings of geovalidation it would be impossible to do the exact interpretation of top of Pannonian sediments. These sediments represent the main source rocks in Vojvodina. Additionally, they sometimes can be presented with reservoir rocks. The importance of knowing their distribution is priceless in aspect of hydrocarbons evaluation.
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Some Application of Wavelet Transform In Seismic Data Processing
Authors T. Sretenovic, M. Cvetkovic, K.J. Marfurt, N. Pralica and S. Chávez-PérezGround-roll, swell noise, guided waves and random noise are just some of most persistent types of noise in land, marine and OBC data and can be hard to remove with traditional methods. Many different techniques based on Fourier transforms are used to suppress noise in exploration seismology. Wavelet Transform presents a new tool to aid seismic processing and they have been successfully applied for compressing and de-noising purposes. For pre-stack filtering, 1D and 2D Wavelet Transform-based filters have been proposed by Deigahn and Watts (1998), Yu et al. (2002), Yu and Garossino (2005) and Abdul-Jauward and Khene (2000). In this paper we reproduce some of the algorithms used in the research community, and further test and develop them. We use both 1D and 2D Stationary Wavelet Transform-based filters to suppress ground-roll, acquisition footprints and random noise. We also consider resolution enhancement in wavelet transform domain, with some observations and preliminary results. Because most of these techniques are applied on post-migration data they present very inexpensive and computationally efficient solutions. Any new information about structures and subtle geological information that can be derived after application of this type of technique can lead to new discoveries (Countiss, 2002).
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Application of Passeis: an open-source seismic data processing package
By H. ZhengAs an in-house, free of charge and open-source processing and visualization package focusing on passive seismic data, Passeis is developed based on the Matlab Graphical User Interface (GUI). The software package can be employed by both academic and industry environments due to its flexibility. It can be executed by running Matlab 7.5.0 (2007b) or higher versions under both Linux and Windows operating systems. A total of 63 modules have been integrated into the current version, which can be roughly casted into the following 10 module-groups: Input and Output, Traces, Data, Frequency, Correlation, Source, Model, Modeling, Coordinate and Interpretation. Although Passeis initially has been designed to handle the long-recorded passive seismic data (especially within the low frequency range), it is still applicable for any kind of seismic data. The key power of Passeis is its robust core and open environment which permits the user to easily and quickly build his/her own modules into Passeis by using the module template. These features are very important when developing software tailored for passive seismic data processing and visualization because most of present methods or ideas for handling such data are basically immature. A numerical experiment of combining seismic interferometry with time-reversal modeling (TRM) to image (actually is locating) the possible low-frequency underground noise burst associated with a reservoir, has been addressed in this paper as an application of Passeis
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Monitoring of CO2 sequestration in ultrasonic laboratory
Authors D. Sijacic, K.H.A.A. Wolf, R. Arts, K.H.A.A. Wolf and R. ArtsPotential of time-lapse crosswell tomography in monitoring CO2 underground storage is tested in a case of specific geological setting – thin coalbed seams. In contrast to tick reservoirs of sandstone aquifers, thin coal seams are difficult to image. In first European pilot project of CO2 injection in thin coal seams (RECOPOL) seismic monitoring was not successful. In laboratory, using ultrasonic measurements we investigate possible reasons and main problems. Furthermore, we test two different theories (ray and finite-frequency wave theory) underlying imaging method and their performance in monitoring of CO2 injection.
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A Wireless Sensor Network for Seismic Activity Registration
More LessThe scientific requirements for reliable data collection and precision event detection are the main features of the geophysical monitoring. The main contribution of this paper is an evaluation of the Wireless Sensor Network as a scientific instrument, bringing it up to the standards of existing instrumentation in terms of the quality and accuracy of the recorded signals and quantity of the captured data. We perform a detailed study of the sensor network's data using a direct comparison to a standalone data logger, as well as an investigation of seismic and acoustic wave data pass through the the network.
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Migration of Material in the Tectonosphere and Riftgene Structure of the Lithosphere
More LessThe tectonic processes in the lithosphere can be considered within the "system of migration of the material into the tectonosphere ". These processes go on in a complex “closed circle” in which the following 3 general processes of migration of material in the tectonosphere are differentiated: • Migration of "the mantle in the lithosphere" (upwards migration); • Migration of "the lithosphere in the lithosphere" (horizontal migration); • Migration of "the lithosphere in the mantle: (downwards migration). The cycle of migration of material is closed by "migration of the mantle in the mantle", which is carried out within the convection flows in the mantle. The migration of the material results in "structuring of the lithosphere" from a finite number of rift-systems, equal to the number of rifts in the lithosphere". The evolution of a rift-system includes a magmatic cycle (from basic plutonites to finishing acidic magmatism), syngene and orogene processes and subsequent sedimentation.
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Determination of the Groundwater-Surface Water Relationship by Using Electrical Resistivity Tests at Develi Closed Basin
By F.E. YildizDeveli Closed Basin is located at the southern of Kayseri City in Turkey. Develi Closed Basin is the sub-basin of Kızılırmak Basin. Generally flood irrigation has been used in this basin, surface water resources are not sufficient to cover irrigation water requirement so groundwater is used for the irrigation. There is excess groundwater abstraction at this basin. If there is any relation between groundwater and surface water of Sultansazligi then this cause water scarcity at the wetland so this study introduces the studies about the determination of surface water groundwater intrusion
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Granite and granodiorite identification using spectral unmixing techniques
Authors D. Borisova, B. Banushev and H. NikolovThe development of efficient technologies for data analysis is one of the most challenging issues that the remote sensing community is facing. Matters of data reduction, processing algorithms accuracy, information amount, cost and time saving determines the efficiency of data analysis. The importance of this issue is directly connected with the ever-increasing quantity of data provided by numerous airborne, field and laboratory operated sensors, with their synergistic use as well as with the accuracy of data processing algorithms and results verification. We present here some results from a study of different spectral unmixing techniques over two similar rock types such as granite and granodiorite in relation to objects type and proportions determination. Experimental data from field and laboratory spectral reflectance measurements in the visible and near infrared band are used. Various decomposition methods (linear unmixing, clustering) are applied and evaluated. Spectral linear unmixing is efficient approach to the spectral decomposition of multichannel remotely sensed data. A main problem to its process is that the number of spectral components (has to be correctly distinguished. Therefore, the evaluating of the possibility of using spectral mixture decomposition in relation to their type and proportion determination for subpixel identification is described.
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