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7th Congress of the Balkan Geophysical Society
- Conference date: 07 Oct 2013 - 10 Oct 2013
- Location: Tirana, Albania
- ISBN: 978-90-73834-55-2
- Published: 07 October 2013
1 - 100 of 110 results
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Detection of Fractures Stoneley Waves - Application - Example on a Oil Sinks in Algerian Sahara
By D. MabroukIn this paper, it is applied to acoustic data processing to study the fracturing tank oil on a well drilled horizontally using Stoneley waves the different stages of treatment allowed to detect, in a first step, areas of high attenuation energy .. The study of the Stoneley wave reflections has finally detect the fracture zones of the reservoir
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Gravity and Geo-Electric
More LessThere are so many complex geological appearances having been discovered by professional Geoscientist in Bayat. This research aims to investigate the contact of igneous rock and metamorphic rock.
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Geo Electric Three-Dimension Surveys for Detection of Subsurface Structures
More LessResistivity electrical changes in vertical, horizontal and in the direction that is perpendicular to the survey line, is measured in 3D surveys. 3D electric data illustrate a 3D image from subsurface layers, therefore combination of3D electric results and surface geology is appreciated as helpful technique in electric data interpretation. What Is carried out for performing a 3D survey is as follows: first a 2D survey is carried out in the survey field and then collected data are interpretated. When the subsurface layers are defined clearly, an area is selected and a suitablegrid for 3D survey is designed. After data acquisition, by using a 3D interpretation software, data points areinterpretated. Finally, the results are compared with the result of 2D configuration. In this study, the mainobjective is the detection of a fault trend by using pole–pole electrode array which is commonly used for 3Dsurveys. This survey method by using a 3D interpretation model gives accurate results of subsurface structures. In order to confirm the abilities of this method for fault detection, after checking the final results of 2D Shlumbergerarray on a fault trend in Anarak area in Esfehan province, an square grid with a 60 meters long, .
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Investigation of Sabalan Geothermal Field Structure Magnetotelluric Method(MT)
More LessSabalan geothermal field is a high potential geothermal system in Ardebil province N-W of Iran that is now under investigation for the electricity power generation .In this paper the fourteen MT stations of 1998 MT data set were used along a profile perpendicular to the main geological structures in order to assess the three main elements of Sabalan geothermal field namely cap-rock, reservoir and heat source. TE and TM mode data and skew parameter show that the earth dimensionality differs from site to site, so we examine the joint 2D inversion along the profile. The two-dimensional inversion has been done by using a code from Siripunvaraporn and Egbert (2000).The resulting model show a pattern of high–very low–low resistivity with depth. The high resistive layer at the surface is governed to a great extent by basalt, andesitic and old trachyandesitic flows and other impermeable rocks that have thermal conduction and acts as the cap-rock of the system. The second layer is a very conductive layer and interpreted as the reservoir with thermal convection and hot fluids contained in its fractured and pores.
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Geophysical Overview on Contact between the African and Eurasian Plates Transverse Folded Belt of the Albanides
Authors A. Frashëri, S. Bushati, N. Frashëri and S. DemaThe article presents an attempt to generalize the integrated geophysical data: Gravity, Magnetic, Paleomagnetic, Geothermal, Seismological and Remote Sensing images of zone, where it crosses the deep transversal fracture Shkodër – Pejë. Analyses of the geophysical data are based on regional geological setting data of Shkodër-Pejë sector of Mediterranean Alpine Folded Belt, which presents the existence of important disjunctive deep tectonics element. Shkodër-Pejë tranversal fracture represent the contact between the African and Eauasian plates contact transverse territory of folded belt of the Albanides. The geological mapping at the scale 1:25.000 up to regional ones at the scale 1:200.000, does not have traced at the Earth’s surface the outcrop of this thrust. Consequently, have brought about the different concepts on it, from “scharung” (1901) to “transform transversal fault” (1970-2012), and to silence about its existence, even to denial of its presence. These changes in the course of a century, not just in terms of use, were related to different geological schools over the geological setting of the Albanides. The integrated geophysical information has cast light on the depth of the area, where it crosses the transverse Shkodër-Pejë that represent a deep transverse vertical fracture, which affects the Moho Discontinuity.
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Geosciences - The Contest Has Change
Authors G. Kallfa, J. Hinzer and L. KapllaniA nation's prosperity will be enhanced by the discovery and exploitation of economically viable natural resources within its borders; processes that are more than ever subject of rapid changes and increasingly dependent to the political, financial and marketing factors. In the last two decades the natural resources industry worldwide experienced dramatic irreversible changes. In the oil and metallic ores sector, countries, including Eastern Europe, emerged in global financial and economic markets. The big state-owned mining companies collapsed and/or transformed into private companies, many mines were closed. On the other hand, private sector is talking over the financial part of managing, developing and exploiting natural resources, consequently the new emerging in market countries have to compete in order to attract the attention of major financial institution and companies. The scope of presentation is to explain some of major changes in natural resources industry last decades that directly influenced or will influence the future of geosciences and business models in emerging markets. The authors, based on their long international experience in mining sector, will try to identify some of most influential factors and how the geoscientists must respond to the new era of managing, developing and marketing countries’ natural resources.
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Time-dependent Aftershock Seismicity Patterns and Their Propagation - The Van Earthquake (7.2), 23 Oct. 2011, E-Anatolia
By M. TokerThe Van earthquake (ML 7.2, 23 October 2011) occurred in E-Turkey, typically “intraplate” earthquake. Aftershock seismicity pattern of the Van earthquake indicates the most prominent type of compound-complex earthquakes due to its multifractal dynamic complexity and uneven compressional nature, ever seen all over Turkey. Aftershock seismicity of the Van earthquake can’t be explained with linearly uniform, elastic fracture mechanics, because the time delays between the observed individual clusters are too long to result from elastic processes. The Van earthquake dynamically loads the surrounding volcanic region, such a compound earthquake can result from viscoelastic relaxation in the immediate postseismic period, resulting in nonlinear and heterogeneous redistribution of loads. Van earthquake as a composite system has input parameters more than one and strongly characterized by composite sequences of event instabilities. This brings an idea that is intraplate seismicity of accretions, giving a possibility of the extensive investigation of post-collisional rheology of accretionary complexes. We conclude that, in Lake Van, the deep-reaching zones of weakness allow magmatic intrusions into upper crustal layers, where magma-fluids or unstable fluctuations of the magma chambers themselves may cause the generation of unstable evolution and propagation of earthquake sequences.
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Petrology of the Eastern Taurus Ophiolite (Turkey)
Authors A.F. Bingol and M. BeyarslanThere are many ophiolitic massifs, situated either northern or southern flank of the EW-trending Pütürge-Bitlis Metamorphic units, that they inform a good tectono-magmatic model for the Neotethyan ocean during Mesozoic in Taurus Oriental. They are, from west to east, Kızıldag, Koçali, Göksun, İspendere, Guleman and Gevaş. They consist of mantle peridotites, oceanic crust units, such as mafic cumulats, isotropic gabbros, sheeted dyke complex which are covered by the basaltic pillow, massive lavaş, and isolated diabase dykes. Some ophiolitic massifs as Koçali, Göksun, and Gevaş and tectonically overlying metamorphic units were intruded by tonalitic and granodioritic intrusions. The mantle peridotites are generally harzburgite and less lherzolite, mafic rocks consist of layered and isotropic gabbros cutting by wehrlitic intrusions. Geochemical data indicate the presence of two different types of volcanics, MORB and suprasubduction. The age of the volcanic rocks have been assigned to Late Triassic-Upper Cretaceous based on the radiolarian data from the associated pelagic rocks units. On the basis of petrography, geochemistry andage data, we conclude that the evolution of the eastern Taurus ophiolites involved at least two stage episodes. The first stage is presented by MOR type rocks and the second stage is characterized by SSZ type rocks.
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Thin Bed Contourite Seismic Imaging
By S. SunjayWavelet (Mathematical Microscope) analysis of seismic data is made fashionable for thin bed precise subsurface imaging and interpretation. 3D seismic data interpretation for subsurface imaging of thin bed contourite systems is integral part of research work . Seismic expression of bottom current deposits from that of other related deepwater sediments (turbidites, hemipelagites, debrites, etc.), and to maximising the information that can be derived from seismic data. A wide variety of seismic facies are common in contourites, most of which are equally present in turbidite systems. Seismic facies associations that may be typical of contourites are still to be defined. Seismic characteristics also depend very closely on the methods of seismic acquisition and processing. Sediment waves and channels are very common both in contourite and turbidite systems, and not specifically diagnostic of either system. Slope deformation, sediment creep, and large-scale water-escape may cause a hummocky seismic facies that can be misinterpreted as sediment waves. The identification of hydrocarbon reservoirs from seismic data is a key issue in the oil industry. Texture Segmentation of a 3D Seismic Section with Wavelet Transform is employed for pattern recognition.
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The Use of ERT, Magnetic and EM High Resolution Methods in Archeological Sites - A Case Study in Apollonia, Albania
Authors H. Reci, I. Jata, S. Bushati and M. HaxhimihaliDuring the period 2011-2012, high resolution geoelectric surveys using Electrical Resistance Tomography (ERT), Magnetic and Electromagnetic surveys, has been carried on three archeological sites of Bylis, Apollonia and Tirana Castle, Albania. The geoelectric surveys of squares, was carried out with 2D ERT parallel profiles with distance between them 1.5m or 2m and the distance between electrodes 1m where a multicore cable with 30 takeouts was used. The squares have been surveyed using two geometric configurations, Wenner and Schlumberger arrays. The EM survey grid is 1x 0.5m, whereas the magnetic grid is 1x1m. A 3D interpretation of resistivity profiles has been carried out and the resistivity distribution maps of different depths have been taken. At the same time the 2D map of magnetic anomalies is taken after the appropriate diurnal corrections. The EM 3D maps, show the ground scanning of the conductivity of the underground. From this study we conclude that the ERT method delineates very well the thickness of cultural layer and the buried archaeological objects inside it where the anomalies taken correspond with magnetic anomalies, whereas the EM method delineates very well the conductive clays from the other surrounding formations.
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Radioactivity of Phosphorites and Some Opinions on Their Genesis
By A. SerjaniAbstract In Albania there are discovered phosphorite mineralization of the Upper Cretaceous (Coniacian) and Middle Jurassic. The application of radioactive methods have had concrete results and have solved concrete problems (Dafa F., Serjani A., 1994): theoretical solving of the character of distribution of useful components U and P2O5; determination of the mutual correlations between U, P, F and Gamma intensity, discovering the coefficients for the main chemical and radio metrical constituents etc. The differences of the uranium content between Coniacian Phosphate Horizon and Middle Jurassic uranium-bearing mineralization can be explained by their differences in genetically aspect. The formation of phosphate-carbonate-siliceous horizon happened into the pelagic, deep sea, reduced environment of Ionian Trough, where the clastic, terrigenous matter is totally missing, and phosphate beds are very clean, constituted only by phosphate and calcite minerals. Middle Jurassic uranium-bearing phosphorites were formed in photic zone, in shallow water environment, on submarine mountains (high parts) of break in sedimentation. Phosphate mineralization is accompanied by high content of organic matter, dolomite, pyrite, quartz and some other detritus minerals. The high content of uranium can be explained due to above mentioned accompanied constituents and by the absorption during digenetic processes.
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Sunspot-dependence of the Geomagnetic Daily Variation in Turkey
Authors C. Celik, E. Tolak-Ciftci, M. Zobu, H. Ozener, S.B. Tank, A. Kizmaz and N. SarikayaIn this study the hourly mean values of the geomagnetic data available in Turkey are analyzed to determine principal harmonics of the solar daily geomagnetic variations. Available data are grouped according to sunspot relative number to determine and analyzed for solar and lunar harmonics. The most disturbed five calendar days of the each month are removed in order to minimize the effect of current systems in the outer magnetosphere regions. Very good sunspot dependence found between solar harmonics and sunspot number.
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Assessment of the Seismic Impact from Grouped Quarry Blast Using Standard Seismic Survey Equipment
Authors S.B. Shanov and M. IsaevThe study presents a methodology for using standard seismic survey equipment for assessment of the impact of grouped blasts from quarries. Example from а limestone quarry situated at more than 1.5 km from the thermal spring “Merichlery” in South Bulgaria is discussed. After the two strong earthquakes from 14.04.1928 (М=6.8, Chirpan Earthquake) and from 18.04.1928 (М=7.0, Popovitsa Earthquake) the water from the spring disappeared. A survey was executed for assessing the impact of the blasts on the houses and the discharge of the mineral water from the exploitation borehole. The results are compared to the national and international criteria for the safety limits of accelerations and velocities of the ground in relation to the seismic frequencies. Reference to the maximum expected ground accelerations from earthquakes on the concerned site is also presented. The maximum vertical acceleration from the quarry blasts was calculated to be between 32.81 and 57.62 cm/s2, and the horizontal one – between 37.51 and 233.95 cm/s2 (single high frequency picks). These results indicate that no one record overpasses the normative level of accelerations from earthquakes for the area - 0.27 g (265 cm/s2). In average the recorded accelerations were 2.5 times lower than the normative.
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Pre-stack Depth Migration (PSDM) Using Tomography Based Velocity Model
More LessNowadays, the requirements for obtaining high resolution seismic sections lead to searching different approaches to processing and interpretation of the data. Creating depth sections by Pre-Stack Depth Migration (PSDM) is a key issue for obtaining more reliable and informative seismic sections, which in turn enable more confident and more reliable interpretation of seismic data. Depth imaging of seismic data is used to map the complex subsurface geology in areas that have steeply dipping structures, faults or in any areas with a rapidly changing geological environment. The main aspect for achieving high quality depth imaging is the ability to build detailed and accurate velocity model. The model building process involves making an initial estimate of interval velocities for each layer in the model, followed by iterative refinement of the model velocities and layer thicknesses until residual moveout has been minimized on depth migrated gathers. Accurate velocity estimation and depth imaging provides the key to understanding the subsurface.
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Detection of Zones Characterized by Different Degree of Water-saturation and Mapping of Landslide Surfaces by Application
Authors S. Dimovski, N. Stoyanov, A. Kisyov and M. YankovaGenerally, the landslides study is aimed towards determination of their physical- geological characteristics and the peculiarities of their structure. The main tasks are detection of zones characterized by different degree of water-saturation, mapping of landslide surfaces and contact zones, along which is performed the rock mass movement, determination of the shape, the dimensions, and the spatial situation of the landslide body. The possibilities, provided by the non-invasive geophysical methods, for solving the above-defined problems depend mostly on the landslide physical-geological model. Usually the geo¬logical section of a landslide site is well differentiated according to electrical resistivity. For this reason geoelectrical techniques applied for obtaining high-resolution images of the underground resistivity have leading role in geophysical investigations of landscapes. In this study are presented results obtained from the application of electrical tomography for investigation of a landslide site on the territory of Bulgaria - near the town of Varna.
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An Overview of Eastern Black Sea Crust Using Single Station Fundamental Mode Surface Wave Method
More LessIn this case study, crustal structure of the Eastern Black Sea (EBS) have been investigated by calculating and inverting group-velocity dispersion data of fundamental mode surface waves (Love and Rayleigh) using single-station method between the periods 4-40 seconds. For this purpose, we have used broad band (BB) recordings of three earthquakes recently occurred easternmost EBS recorded on KOERI (Kandilli Observatory and Earthquake Research Institute) BB stations (BZK, DIKM, KVT, SNOP). Computer Programs in Seismology package version 3.30 (Hermann, 2002) were used to both calculate observed fundamental mode group velocity dispersion curves and inversion of these curves to determine 1D shear wave crustal structure of the region. We have statistically averaged the group velocity dispersion curves for Love and Rayleigh waves. Then, mean dispersion curve of these waves has been inverted to determine 1D shear wave structure represents the region. Consequently, we have determined that there is a low-velocity zone in the upper crust corresponds to Maikop formation. The lower crust consists of oceanic/semi oceanic thickened crust. Moho depth is 31 km.
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Integration of Geophysical Studies in Near Coastal Lowland of Albania with Technology Gis
Authors F.V. Vinçani, P.L. Leka, P.K. Kosho and P.N. NaçoDuring the period of 20 years in near coastal Lowland of Albania, many geophysical studies have been carried out with Electrometric, Magnetometric, Gravimetric and Radiometric methods. Important place in these studies has taken Electrometry, mainly the method of resistivity. Results obtained in the most important regions of near coastal Lowland provide the supporting basis for all infrastructure projects and major works. Geophysical studies have provided research-scientific information to the surface and in depth, helping in solving geological, geoenvironmental, civil geology, geological-sedimentological, geological-engineering, hydrogeological and archaeological tasks in varying degrees. To standardize the information collected over the years, to coordinate and to annex it to any other type of support information for performing processing, further riinterpretations, it was necessary to use technology GIS (International Geographical System) in order to integrate them. Geological-geophysical studies included in these region resolved tasks: determining of the thickness of Quaternary deposits, the study of land for social buildings, exploration of minerals, researchs for waterbearing and the microzone of some regions. Based on existing technology (hard-software) was achieved to build GIS for geophysical studies at this region of Albania. Process has passed some phases like as: data preparation, informatization and processing etc.,
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Determination of the Neotectonic Movements through Geophysical Methods in the Elbasani-Kruja-Lezhe Region
Authors P.L. Leka, P.N. Naço, F.V. Vinçani and P.K. KoshoThe article presents the analyze of geophysical surveys: Geoelectric, Seismic for the determination of the neotectonic movements in the Elbasani-Kruja-Lezhe region. 2-D geoelectrical image of the profile “Vidhas-Gjergjan”, related to the neotectonic system of faults is characterized complicated, creating graben structure in the central part of this profile due to the normal slides situated with neotectonic system of faults in the valley of Shkumbini’s River time to time. 2-D geoelectrical image of the profile “Krastë-Shushicë” related with extensional neotectonic regime.The separation of geoelectrical layers of Mirdita’s zone with sub-zone Krasta and aftermost with Kruja’s zone represents the extensional neotectonics of these zones with different dip from the upper part to the depth. Obtained data from the interpretation of seismic profile have helped in the conception of geotectonic model of Elbasan’s water basin. In such conditions is formed graben or cumulative depression of Elbasan, also expressed through seismic facies 0.6 to 0.2 sec. Geophysical-engineering study in Kruja region has identified the sliding plan and their active areas, helping in the selecting of construction sites. Active areas of the sliding are located usually in parts with steep terrain and this phenomenon is distinctly observed in the eastern part of neighborhood Kasme.
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Fracture Detection and Determination Its Orientation Using Different Geoelectric Null-arrays
More LessA comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-g null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode is presented. The term “geoelectric null-array” is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space.The main objective is to determine which array(s) best localise vertical structures or best identify their orientation. Forward modelling of the three null-arrays revealed that the Wenner-g and Schlumberger null-arrays localise vertical fractures the most accurately, while the midpoint null-array combined with the Schlumberger null-array allows accurate orientation of a fracture. Field test measurements were carried out to verify the theoretical results above a quarry in Les Breuleux with the three null arrays and many classical arrays. The results were cross-validated with quarry-wall geological mapping. In real field circumstances, the Wenner-g null-array showed to be the most efficient and accurate in localising fractures. The orientations of the fractures in accordance with the numerical results, were most efficiently determined with midpoint null-array, however Schlumberger null-array adds accuracy to the results. This study shows that geoelectrical null-arrays are better than classical arrays for the characterisation of fracture geometry.
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Seeing Deeper by ERT Measurements
Authors S. Szalai, A. Novák and K. SzokoliDepth of investigation is studied here, because nowadays more and more research should be carried out in built-up areas where space is limited, that is this question becomes more and more important. Since we think that the depth of investigation is basically determined by the detectability of small-size inhomogeneities, the so-called depth of detectability (DD) values, this parameter is investigated in this presentation for the 2D ERT. In the case of the studied prism and dyke models the not-yet investigated g11n arrays gave systematically higher DD values than the pole-dipole and dipole axial arrays which were the best conventional arrays from this point of view. This makes possible to obtain useful information even where the measuring area is limited, eg. in settlements, in less time and from greater depth. Moreover, due to the imaging properties of arrays having larger DD values are generally better it is easily possible that these arrays have also better imaging properties than those of the traditional arrays.
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New Arrays in the Geoelectric Prospection
Authors S. Szalai and K. SzokoliThe g11n arrays, which were until now outside of the interest of the geophysicists will be introduced. These so called quasi null arrays can be more effective in detection and characterisation of anomalies have just a small impact on the potential (due to their small size, resistivity contrast to the host rock, and/or their large depth) than the traditional arrays. In many investigations they proved to be even better than the Stummer array which was constructed by an optimisation procedure from the set of the traditional arrays. The g11n arrays proved to be moreover significantly better in horizontal and vertical resolution investigations and in some more models, as well, than even the optimised array. According to our theoretical and numerical investigations the usefulness of these arrays can be expected in numerous other geophysical research areas, as well. It is however already seen that the g11n arrays can be valuable tools for solution of many problems similar to the investigated one, like e.g.: in the research of tunnels, caves, cables, abandoned riverbeds, or discontinuities in the clay layer below a waste deposit. The applications of these arrays require moreover less time to carry out the measurements than those of the traditional arrays.
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Applying Edge Mapping Functions to the Magnetic Anomaly of the Philippi Granitoid in N. Greece
Authors G.N. Tsokas, A. Stampolidis, P.I. Tsourlos and G. VargemezisAirborne magnetic surveys provide a cost effective, quick and accurate way to map the subsurface distribution of magnetization for large, usually inaccessible, areas. Differences in magnetization of rock units are related with differences in the content of magnetic minerals within rock units (i.e. their magnetic susceptibility) and their remanent magnetization. Assuming that these properties are discernible between the various rock units, magnetic field anomalies could provide valuable information for the texture of lithological units and even be correlated with distinct lithologies. Here, we evaluate a number of edge mapping techniques applied on a part of the magnetic map of Macedonia and Thrace (N. Greece) in order to delineate the edges of the magnetic sources. The magnetic field anomaly which is studied is created by the so called Philippi granitoid. The mappers used comprise functions of the anomaly and its derivatives. The aimed in locating the lateral limits of subsurface magnetized granitoid.
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Some Main Aspects and Features of Seismic Activity in Albania During 2012
By Rr. OrmeniAlbania is characterized by intense microseismic activity and small and medium-size earthquakes and only seldom by large event. We present here the results of the analysis in parameters of events and some features of Seismicity that have occurred in the Albania and surrounding area during 2012 year. On that territory 39°00’-43°00’ N and 18°50’-21°50’E there are 869 located earthquakes with magnitude M≥1.5 (Richter), 196 with magnitude M≥3.0, 19 with magnitude M≥4.0. The most of local earthquakes about 92% are distributed in depth between 0 and 25 km, with maximum concentration between 4 and 12 km. The earthquake foci are concentrated mostly along the some active faults: 1) In the Vlora-Elbasan-Dibra transversal fault zone. In the vicinity of Fieri was registered a small series of earthquakes that have the same level of of magnitude and supposed to be an inducted seismicity. 2) In The Korca-Leskovik seismogenetic zone. 3) In the Ionian seismogenic zone. 4) In the Lezha-Ulqini seismogenic zone. Increased seismic activity was registered on the Greece territory, nearby of southern Albania.
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Crust and Upper-mantle Structure in Anatolia from Analysis of Love Wave Group Velocity
By N. SayilThe environmental noise, the noise related to signal, the equal sharing of seismic energy between the components and the other factors effect discrimination of surface waves forms on seismograms. The differences between polarization properties of surface waves and microseismic noise permit to filtering a desired surface waves kinds on three components records. Dispersion property of surface waves, i.e. changes in seismic velocities and absorption as depending on frequency, has been used to investigate the Earth crust and upper mantle structure. In order to investigation of the Anatolian crust structure, it has been selected the profiles across east-west trending the Anatolia. To create these profiles, long period three component digital records at six stations (YLVX, MRMX, MLSB, ISP, ISK,EDRB) of KOERI network having about 10 epicentral distance of an earthquake (EZM) were taken. Surface wave discrimination filter based on the polarization has been applied to three component records of all stations for making more convenient the surface wave records. Multiple filter technique has been applied to discriminated surface waves and detected the group velocities. A five layered crustal model having total thickness of 38-40 km and Pn-wave velocity of 8.00 km/sec in the upper-mantle have been determined by inversion process.
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Determination of the Site Characteristics from Mictroremor Measurements in Gumushane Campus Area
More LessMicrotremor method used for engineering seismology is very important for determining of dynamic ground parameters and its variations. Method based on frequency of horizontal and vertical component microtremor records provides to quick and economical estimation of dynamic ground parameters. Most important advantage of Nakamura method defined as single station method isn’t required reference point and it can be applied easily in the area with low seismic density and without base rock. In this study, Nakamura (H/V) method has been applied to microtremor records taken with CMG-6TD three component broad band velocity seismometers in 6 profiles and 40 points with the aim of determining ground predominant period and magnification parameters of the Gumushane University and its surrounding area located in Northeast of Turkey. Maps of magnification, predominant frequency and ground classification (Z2 and Z3) according to the predominant period are created by derived values.
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Contribution of the Seismic Method in Structural Modeling of Albanides
Authors P.N. Naço, P.L. Leka, J.S. Skrame, F.V. Vinçani and V.D. Dodaod will illustrate its results in different regions. The studies carried out by seismic method in terms of depth has could to outline the transgressive boundaries, overthrusting tectonic contacts, backthrusting tectonic boundaries, possible structures for petroleum exploration, the new tectonic movements etc., specifically in structural determination of Tirana syncline, outlining of Preza-Ishmi overthrust, which is active to this day, outlining in depth of the contact that separates the tectonic Kruja zone with tectonic Ionian zone. It will also be presented the possible structures for petroleum exploration, outlining in depth the oil-gas –bearing deposits.
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Effects of the Borealis Impact on the Thermal Evolution of Mars
Authors A. Fazelvalipour, Y. Vejdani, E. Fazelvalipour and M. BakhshimazdeThe near hemispheric dichotomy of Mars is attributed to a giant impact called Borealis impact[Andrews-Hanna et al., 2008]. In this work, we investigate the effect of Borealis impact ,happened 4.5 Gyr ago, on the thermal evolution of the Martian planet. We show that the impact increases the rate of crustal production for a period of about 50 m.y. after the impact, reduce score mantle boundary heat flux significantly for a period of less than 5 m.y. after the impact but does not change significantly the total volume of melt production of the Mars. We discuss implications of our results on the postulated equivocal theories on the demise of Martian dynamo and conclude that none of them is capable to explain the demise of the Mars magnetic filed happened about 4 Gyr ago
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Assessing the Seismic Hazard for some parts in Hormozgan Province, Southern Iran
Authors A. Fazelvalipour, Y. Vejdani, E. Fazelvalipour and M. BakhshimazdeAn epicentral map of the region with magnitude 3 till 7 for the period 1930 – 2007 showsthat the region to the Hormozgan Province , Southern Iran (52º 30’ - 59º E, 25º –29º N) is one of themost active region in Iran. In this paper a method is developed to produce for the engineer thedesired relationships between such ground motion parameters as Modified Mercalli Intensity (MMI)and their average return period for some parts (Bandarabbas Zone, Hajiaba Zone and Minab Zone)of that province. In addition we have calculated a relationship between return period and MMI for three parts of Hormozgan province, Southern Iran.
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THERMTEC - Thermal-tectonic Modelling of Orogenetic Processes in the Eastern Alps
Authors S. Hoyer, F. Zekiri, G. Goetzl, M. Bottig, M. Fuchsluger, M. Rockenschaub and N. GegenhuberThe scope of the project THERMTEC is to model thermal-tectonic orogenetic processes in the Eastern Alps. Regional geothermal regimes are influenced by tectonically induced processes in terms of uplift or depression, which in combination with exogene processes like erosion and sedimentation lead to significant geothermal anomalies. This study aims to investigate the influence of two antithetic tectonic processes on the recent geothermal regime for the Tauern Window in order to detect possible zones of positive and negative heat flux anomalies. Geophysical, geochronological and petrophysical investigations as well as 3D geological modeling (using GocadTM) are part of the research. Using the software package COMSOL MultiphysicsTM coupled thermal-tectonic modeling will be carried out during several steps focusing on a regional scale geometric 3D model covering the whole Tauern Window. Starting with a conductive, steady-state model and leading to more complex simulations (transient advection and mass movement). Results will be compared with observed recent terrestrial heat fluxes, palaeothermal conditions gained from geochronological data.
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The Use of Resitivity Methods for the Exploration of Water-bearing Stratums in the the Quaternary Deposits
More LessThis study presents examples of Vertical Electrical Sounding (VES) resistivity methods used for hydro-geological exploration in Albania. There are given examples of VES method, for the exploration of water-bearing reservoirs in Vjosa river valley in Llakatund area. It is presented the geometry of the aquifer in the area according to resistivity data and the correlation between hydrogeological and resistivity data. Also, it is given the geoelectrical cross-section along the Mati River, which gives the opportunity for the study of the water-bearing deposits in all the quaternary deposits of this river.
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Indoor Radon Concentration to Different Lithological Conditions in Shkodra Area, Albania
Authors S. Dogjani, I. Jata, I. Milushi and H. ReciThe studied area is located in the north-west of Albania in urban areas of that area. Radon activity in indoor air was measured by passive and active detectors. Radon concentration survey has been carried out in schools and kindergartens. Depending on the detectors used in measurements, the long term and in a few cases is the use short term methods have been applied. In this research, it is included the results taken only for the 26passive and 15active detectors in schools and kindergartens. In addition, the results of the other 25 detectors are in the procedure of analyzing. The choice of the measured areas is related to the different geological formations. The investigation area shows low- medium – high radon indoor concentration. Keywords: radon, indoor air, soil, red clay, permeability, terra rossa.
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Engineering Geology Mapping for Seismic Microzoning Purpose in Lezha Town Area, Albania
More Lessnds in northwest of Albania, closed to Adriatic Sea. Mostly of the Lezha town is built on flat area on both site of Drini River that are consisted of soils with low geotechnical properties. The other part of town is built on hill’s slopes, which are characterize by unstable state. Also, the Lezha area was defined a high hazardous area in Albania related to seismicity. For that, was carried out the engineering geological mapping on scale 1: 10 000 for seismic microzoning purpose and urban area development. The engineering geological mapping were based on geofactors are lithology, morphology, hydrogeology, geodynamics phenomena and physical-mechanical properties of soils and rocks.
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Pseudo-random Sweep Optimisation for Broadband Vibratory Seismic Measurements
By P. ScholtzBroadband vibratory seismic measurements are suited for deep signal penetration, improving reflector continuity and inversion. Seismic vibrators have serious mechanic and hydraulic limitations in emitting very low frequencies, hence special low-dwell non-linear sweeps are the most common drive signals, but pseudo-random sweeps are also considered to achieve satisfactory results. In this study a global optimisation technique used tailored to include several optimisation targets concurrently to reach a workable solution. Since a simple random sweep generated by vibrator manufacturers’ software has serious disadvantages, our optimisation minimises amplitude fluctuations in frequency domain, correlation side-lobe amplitudes and maximises total seismic energy of the sweep. By controlling maximum amplitudes below a certain vibrator specific lower frequency and by minimising instantaneous frequency changes vibrator mechanic and hydraulic limitations are taken into account. The resulting optimised pseudo-random sweeps have much better correlation and spectral properties than a simple random sweep. Also sweep length could be reduced substantially compared to a simple random sweep and a typical non-linear broadband sweep due to the increased total seismic energy achieved by the optimisation process. As a consequence optimum pseudo-random sweeps could be used in high productivity broadband seismic acquisition where resonance effect reductions are important, too.
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Advanced R&D of Geosciences on Synergy of Multidimensional RS-EO, Cosmical Geophysics & Space Sciences
By Z.D. AndonovThis research represents advanced 6D R&D paradigms for evolution of Geosciences up to Space Sciences on fundamental synergy of multidimensional RS-EO (Remote Sensing – Earth Observation), Cosmical Geophysics and Space Physics in the light of actual “Public domains of the Geosciences & Space Sciences”, especially: Global Changes of Environment & Climate Stratigraphy; Planetary Geodynamics; Catastrophic Earthquakes and Volcanoes; 6nD Computational Tomography; Development of Multidimensional Exploration Geophysics for Strategic Energetic and Advanced Earth&Cosmos Technology; Development of Multidimensional 6D-6C RS-EO, Cosmical Geophysics & Space Physics to the 6D-6C (6-Dimensions – 6-Components) and 6nD Synergetical Paradigms for Earth & Space Sciences & Technology… Advanced paradigms of Multidimensional 6D-6nD Space-Time Strategy are aimed to innovative S&T objectives included new 6D R&D aspects, covered: 1. Innovative 6D S-T Coordinate System & Methodology adaptive for multi-waved transitions from 4D-4C to 6D-6C Methodology&Systems. 2. Innovative Multidimensional 6D Space-Time Strategy for Earth-Sun Structure and 6D Geo-Sun Dynamics, 6D S-T Transferences and 6D Turbullences using 6nD Synergy of Earth & Cosmos, 6D Kolmogorov’ Turbullentce and 6D Kalman Space-Time States; 3. Multidimensional & Multitemporal 6D-6nD Synergy Research on Earth&Cosmos Evolution - Fundamental for 6nD System of all Earth&Space Sciences & Technology Systems…
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3D Velocity Structure of the Albania Region Obtained by Inversion of Local Earthquake Data
By Rr. OrmeniThe ‘minimum 1-D’ velocity model (Ormeni 2011) was used as initial model and, therefore, a reliable velocity model for the region was derived. Interesting features and details of the Albania upper and middle crust can be recognized in the final tomographic images. The results show that the velocity distribution is influenced from the geology and the seismotectonic regime of the region. At shallow depths (less than 4 km) the velocity increases gradually with respect to the depth without any sharp variation. On the contrary, the lateral variation of velocity seems to be affected from the geological regime of the region. Our new velocity model solving low-velocity features at shallow depths in the basins and some high-velocity features in the uppercrust.
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Application of Coda Q Method on Broad Band Recordings, from Local Earthquakes, in Albania
By E DushiInterpretation of the high-frequency part in seismograms of local micro to moderate earthquakes can provide a wealth of information about the earth structure within a region.First to draw attention, to these continuous wave trains in the tail portion of seismograms, was Aki (1969). These waves appear immediately after the direct seismic phase arrivals and are termed “Coda”. The cause of their appearance is the superposition of the incoherent scattered phases from random heterogeneity within the Earth’s lithosphere (Aki, 1969, 1980; Aki and Chouet, 1975; Roecker W. S., et al, 1982; Chung, et al. 2009). It has been observed that the decay of coda wave amplitudes, of a local earthquake with time, can provide a quantitative estimate of the attenuation. The method based on this observation is widely referred to as Coda Q (QC). Aki and Chouet (1975) assumed coda waves to be single back-scattered S waves. Based on this model and using CodaQ routine in Seisan v. 1.9.1, (Havskov, et al., 2012) we have analyzed 55 earthquakes recoded by broadband seismological sensors of the Albanian Seismological Network (ASN). Dataset contains mainly local earthquakes and several regional ones. Taking into account vertical as well as horizontal components, secondary body waves S (Sg/Sn) are processed, which dominates expressing higher amplitudes. We determined parameters in the expression, , where in this frequency dependent model of the attenuation properties in the medium, express the quality factor determined for the characteristic frequency of 1 Hz, and α is the frequency term of the model (Dushi, 2011). The procedure description and results obtained are the subject of this paper.
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Exploration Complex Methods of Copper Ore in the Volcano-sedimentary Formation of Porave Area, Puka
Authors I. Milushi, I. Jata, N. Vukzaj and K. GjeciSummary Volcano-sedimentary formation of Porave - Miliska area is constituted by high titanium basalts and sedimentary intercalations represented of argillaceous and argillaceous – radialarite. This formation is characterized by a very complicated structural construction. The area is highly saturated with copper-pyrite sulfur mineralization and up to now 42 sulphide ore showings are found. Three types of mineralization have been identified: (VMS) volcano massive sulphide ore type with almost sharp contacts with the surrounding rocks, quartz-sulphide mineralization (or vein type) with sharp contacts with the surrounding rocks and hydrothermal-metasomatic mineralization characterized by large mineralized zones within which are meet the massive lenses. All field-spreading of volcano-sedimentary formation is covered with complex geological-geophysical works with 50x20 m grid. These works have identified a number of IP anomalies related to known ore bodies and in sectors with no ore showings. Measurements of IP with Dinpol apparatus provide clear differences between the ore body and surrounding rocks (Porave deposit case). The method of body charged also gives very good results (case of Geraj ore deposit). Key words: volcano-sedimentary formation, copper ore, IP measurements.
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Visibility of the Strands of the North Anatolien Fault in the Topography of Marmara Sea - Bathymetric Surveys
By M. ŞenözThe Visibility of the Strands of the North Anatolien Fault in the Topography of Marmara Sea – Bathymetric and Seismic Surveys The Bosporus is a strait that connects the Black Sea with the Sea of Marmara of northwest Turkey. The Black Sea is in the North and the Sea of Marmara is in the South of bosphorus. The Bosporus (Turkish Boğaziçi) Strait is considered to be the boundary between Europe and Asia, and the large city of İstanbul. Turkey is located on both sides of the southern end of the strait. The Gulf of Izmit is the narrow gulf extending to the east from the Sea of Marmara. The city of Izmit at the end of the gulf was heavily damaged by a large magnitude 7.4 earthquake on August 17, 1999, often called the Izmit earthquake, that killed at least 17,000 people. The Izmit earthquake ruptured a long section of the North Anatolian Fault system continuing under the Gulf of Izmit. Another strand of the North Anatolian Fault system is visible as a linear feature in the topography south of Iznik Lake. The recent Bathymetric and Seismic surveys show that the North Anatolian Fault system extends beneath and has formed the Sea of Marmara, in addition to the Gulf of Izmit and Iznik Lake.
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Contribution of Simplified Surface Waveform Calculation to Separate Dispersion Curves in MASW
Authors H. Karsli, M. Senkaya and R. GüneyAccurate picking of dispersion curves is the most critical stage in Multichannel Analysis of Surface Waves (MASW) method. Although there is several acquisition and numerical techniques for the optimal extraction, sometime, this requirement cannot be valid due to interference, which includes different modes, noises, and also lateral inhomogeneity in the near-surface earth. Hence, the interference between the different modes of surface waves can be so serious that neither fundamental, nor higher mode dispersion curve can be extracted with an accurate and a reliable. For this, we calculate surface waveforms, including geometrical and intrinsic dispersion, based on the summation of the particular seismic impulses corresponding to particular frequency-phase velocity curve points for geophone positions from the seismic source. This methodology is demonstrated by using both synthetic and real shot gathers. Synthetic calculations provide us a simple way to check accuracy of dispersion curve picking on a shot gather, which it is the fundamental or higher mode.
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The Effects of a Landslide on the Habitation Objects and the Results of the Use of Two Dimensional (2-d) Electrical Resistivity
By E. SiloThis paper reports a geophysical study of a recently activated landslide in the village of Proseku, Mirdita (Albania), due to intensive rainfall. The surface of the area involved in the landslide is 10 Ha. However, there are indications that the landslide area could increase and affect also other habitation objects. A geophysical investigation of the landslide, using the electrical resistivity tomography (ERT) method was carried out. The geophysical investigation has established the geoelectric section in several points of the longitudinal profile, improving the detailed geological mapping of the landslide.
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WinFoc - A Windows-based Individual Focal Mechanisms Program
Authors O. Polat, E. Gok, U. Ceken, E. Pamuk and S. OzyalinWe present a software dealing with focal mechanisms solutions for educational and research purposes. It gives reasonable results by performing graphical interface of the beachball diagrams. Plots can facilitate to understand the kinematics of fault ruptures. The program is used to examine the nodal planes, calculate the orientation of the Strike, Dip and Rake, and to plot the possible structural model on the block diagram representing the beachball diagram. It is written in Visual Basic 6, and has all the advantages of the Windows OS.
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Repeated Electrical Resistivity Tomographies in a CALM Site in Livingston Island, Maritime Antarctica
Authors A.M. Correia, J. Rocha and G. VieiraDuring the years of 2009, 2012, and 2013 several electrical resistivity tomographies (ERTs) were done in a CALM (Circumpolar Active Layer Monitoring) site near the Bulgarian Antarctic Base of St. Kliment Ohridski. The main objective of the ERTs was to try to identify permafrost zones and their extension, as well as their time and space evolution. Geoelectrical methods, in particular ERTs, are very useful for permafrost studies because of the significant increase of the electrical resistivity when the ground is partially or totally frozen and when temperature is lower than 0 degrees celcius. For each ERT made, 40 electrodes in line, spaced by 2 metres each, were used and the apparent electrical resistivity measurements were mathematically inverted to obtain two-dimensional geoelectrical models for each of them. All models show high electrical resistivity values (of the order of tens of thousands of Ω.m). In the CALM site the high electrical resistivities probably correspond to patches of frozen ground but it is not possible to indicate whether it is sporadic permafrost or remnants of seasonally frozen ground yet.
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Evaluation of Spectrum Behaviour on Acceleration and Displacement Records
Authors E. Pamuk, E. Gok, O. Polat, S. Ozyalin and U. CekenThis study aims; - Using the acceleration records as well as the displacement traces to determine the spectral source parameters described above by using P & S waves and noise records, - Showing the possibility of obtained the corner frequency (Fo) without converting acceleration traces into displacement, - Determining evidences of the parameter Fmax, and, - Comparing the spectrum characteristics obtained from noise, P and S waves both of acceleration and displacement data. Spectral seismograms of 10 earthquakes recorded by acceleration stations of IzmirNet, are presented, here, to discuss spectral behaviour of seismic signals included both acceleration and displacement records. Earthquake parameters of events are also given in the text.
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Geophysical Survey on A Landslide Area is in The Trabzon City Centre Northern Turkey
More LessLandslides pose serious threats to settlements and structures that support transportation. Especially, they threaten human life as a considerable danger in urban areas. That’s why the areas that are affected by landslides should be investigated. Microtremor method used for engineering seismology is very important for determining of dynamic ground parameters and its variations. Method based on frequency of horizontal and vertical component microtremor records provides to quick and economical estimation of dynamic ground parameters. Most important advantage of Nakamura method defined as single station method isn’t required reference point and it can be applied easily in the area with low seismic density and without base rock. In this study, Nakamura (H/V) method has been applied to microtremor records taken with three components broad band velocity seismometers in 3 profiles and 17 points to determine ground predominant period and magnification parameters on a landslide area is in the Trabzon city centre in Turkey. Maps of magnification, predominant frequency and ground classification (NEHRP) according to the predominant period are created by derived values for define slid zone. And MASW method has been applied in the area (3 profiles) to definite S-wave velocities. The results obtained from two different methods are compatible.
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Real Amplitude Processing of Seismic Data in Peri-Adriatic Depression Area, Albania
More LessBased on processing seismic data, a new interpretation is accomplished to evaluate the possible gas bearing targets. In this paper we give some aspects of true amplitude seismic data processing and seismic attributes for gas detection in some areas of Peri-Adriatic Depression. From the whole of factors that affect in seismic signal amplitude, we have compensated in true amplitude processing the spherical divergence, absorption effect, changes of source energy in different shot points of the line, amplitude distortion caused by near surface heterogeneous, etc. Preferably, also, the data ought to be migrated with careful attention to preserving the correct angle-dependence of amplitude. Computer modeling of the available data and correlation of AVO information with other geologic evidence may be required to determine whether or not observed variations of amplitude with angle can be considered indicative of hydrocarbon accumulation. Many aspects of seismic data are not evident on individual CMP gathers, and are visible only when viewed from a broader perspective. The integrated all analysis of seismic attribute displays, integrated also by well data and modeling results have allowed a detailed seismic stratigraphic interpretation.
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Geodynamic Characteristics of Albanian Territory
More LessThe albanian territory belongs to Dinarido-Albano-Hellenic wrinkled belt from the geological point of view. This belt represents the southern branch of Mediterranean Alpine wrinkled belt. It lays (Suess 1983) on southern extension of Alps, along eastern coats of Adriatic and Ionian seas and through Aegean sea passes to Tauride forming as such the wrinkled range of Dinaro-Albano-Helene-Taurid (Fig. 1). The geological structure of Albania in built up from different types of rocks which include quite a wide range of aging. Their age date from Paleozoi as the oldest one untill Quaternari where can be widely found formations of magmatic, sedimentary and less metamorphic genesis. The geological structure of Albanian territory as well is divided in so called inner and outer zones where the first one are located in north-east part of the country dhe the lates zones in south-western part of it. Nowadays the movements of albanian orogjen are towards microplaque of Adria and their relationships manifest features of continental collision.
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Evaluation of Geotechnical Characteristics of Soils through Seismic Surface Waves for the “Ashta Hpp”, Albania
By E. SiloThe seismic refracted method has been used extensively around the world for geological and geotechnical investigations for hydro power projects, etc. Due to the seismic parameters measured in the field and according to the borehole log for all drilling, the Ashta area sites are classified to rock Ashta2 and to stiff soil Ashta1 which are taken into account for the re-evaluation of seismic hazard. Using the multi-channel analysis of surface waves MASW apply through the "SURFSEIS" method have taken the vertical profile of shear waves velocities. A summary of the profile velocities Vp and Vs estimated from seismic refraction measurements and the method of surface waves “MASW” performed in Ashta2 site are shown. Based on the provided Vs30 and SPT-N data, the specific site conditions according to International Building Code, for the sites under investigations are classified as follows: HPP Ashta 1 site to C site class (i.e. very dense soil and soft rock site), HPP Ashta 2 site to B site class (i.e. rock site). The results of seismic hazard for HPP Ashta sites on their specific site conditions at probability 10%/50 years are taken into consideration for HPP Ashta site design.
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Fault Plane Solutions and Geodynamics of Bulgarian Territory and Some Adjacent Lands
Authors V. Protopopova, I. Georgiev, D. Dimitrov and E. BotevFault plane solutions for 128 earthquakes registered by the modern national seismological network of Bulgaria are presented. Geodynamic analysis is performed and some correlations with other geological, geophysical and geodetic results are analyzed. The obtained prevail extensional stresses in Bulgarian territory are explained by two regional geodynamic processes. The first is the post-collisional extensional collapse of orogens under the influence of the paleosubduction in the Ionian sea towards the Bulgarian territory. The second process is the complex influence of the existing SW horizontal movements along the North Anatolia fault in the Aegean Sea, which causes the extension of the eastern parts of the Bulgarian lands and formation of an extensional province towards north from the North Aegean Trough.
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Investigations of the 22 May 2012 Earthquake in Pernik Region, Bulgaria
Authors E. Botev, D. Dimitrov, I. Georgiev and V. ProtopopovaOn 22nd of May 2012 an earthquake with magnitude Мs=5.8 occurred in the town of Pernik about 20 km SW from the capital Sofia causing moderate damages in a wide area including the main city. According to the reports of the seismological agencies and the rapid determination of Bulgarian national seismic network the depth of the event is shallow - about 10 km. The epicentre of the shock is in an area which is relatively quite for the last 120 years minimum. The orientations of the fault plane solutions and distribution of the aftershock epicenters coincide with the NW direction of Pernik-Belchin fault tectonic lineament. As a result, a dislocation model using Okada definitions based on the complex analysis of the dataset is proposed.
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Complex Geophysical Investigation for Development of Seismic Monitoring and Quasi EWS around Pernik City
Authors B. Ranguelov, I. Paskaleva, R. Radichev, S. Dimovski, Ch. Tzankov, A. Kisyov and M. YankovaThe EWS (Early Warning system) is a new technology applied in the advanced and prone to the earthquake risk countries. According of the new project SIMORA new methodology is performed to the seismogenic structure and a seismotectonic model of the region is developed. As the activated fault was not known (so called “blind faults”) deep geophysical complex investigations have been applied. It includes detailed gravity and magnetic fields measurements, new interpretations, comparison with the known and unknown seismic active structures and detailed study of the space-time seismicity patterns. Due to the applied research together with more detailed additional field measurements by electric resistive methods, radioactivity measurements and magnetic susceptibility profiling is expected to make a clear view of the local and regional geophysical fields. After the model is established the new approach for the selection of the strong motion devices locations is executed. Field measurements about the seismic noise (anthropogenic or natural) are performed. The spectral characteristics and amplitude levels are clarified according to the international requirements about reliability. The devices are intended to be put around the seismic source. In parallel such devices can serve as an instrument of the early warning to the local authorities and population.
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A Kinematical Model of the Seismic Early Warning System (SEWS)
Authors B. Ranguelov and T. IlievSeveral models with illustrative pictures are presented covering different seismic possible explicit hazardous situations in Bulgaria: -Vrancea seismic source and distances model -Vrancea seismic source and differences in travel times P and S waves model -Pernik city source kinematics model - distances and travel times of the seismic waves The reliability of the models and obtained results strongly depends on several factors: -The exact positions of the seismogenic faults -The locations of the ground strong motion devices -The kinematics of the travel times of P and S waves -The triggering levels of the device sensitivities -The velocity of data transfer and the reliability of the communication links, etc. The legislation issues and the levels of the warnings need further development due to the sensitivity of the public to the “true and false” alarms. All described issues are under investigations in this paper.
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Possible Sources of Nonseismic Tsunamis in the Baltic and Black seas
Authors B. Ranguelov, G. Mardirossian and I. DidenkulovaThe tsunamigenic sources of nonseismic origin are investigated. The relevant sources for the Black Sea (except earthquakes) might be: - underwater slides - meteorological impact (sashes) - meteorites The relevant sources about tsunamis in the Baltic Sea might be: - meteorological impact (storm surges) - meteorites - fast ferries (anthropogenic impact) Many examples and modeling results are presented illustrating the above mentioned nonseismic tsunami sources with quantitative characteristics of the modeled waves.
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Gravimetric, Mt and Electric Surveys of a N.E. Sicily Regional Fault System
Authors D. Schiavone, M. Loddo and R. QuartoWe present the first results of a geophysical survey carried out on the northeastern Sicily, in an area characterized by a complex structural setting and a significant seismic activity. In the area, 814 gravimetric stations were surveyed together with 27 deep electrical and MT soundings. The gravimetric data were corrected for the topographic effect up to 167 km from each station and interpreted through a 3D inversion procedure. The resulting density model shows the presence of large anomalous bodies, extending at depth, characterized by negative density contrasts. The MT data were processed using the determinant impedances to represent average impedance from which 1D interpretations of the single soundings were obtained. Electrical models were reconstructed along lines. A good correlation is found, both in location and extension, between low density and low resistivity bodies.
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Interpolating and Denoising seismic data by using least square of inverse Radon domain
Authors S.K. Moravej and H.R. SiahkoohiIn seismic data processing and interpretation, we need to have a complete set of data with regular sampling along offset. Therefore, we need to reconstruct and interpolate seismic data at missing spatial locations. Interpolation of seismic data is considered as an inverse problem that we try to reconstruct seismic data at locations where measurements are not acquired, due to problems in seismic acquisition. We propose a new method for Interpolation of seismic data by using Radon domain. Radon domain has three advantages over other domains. First, there are not spatial or other kinds of aliasing in this domain. Second, seismic events are separated based on their dips. Last but not least, removing some traces does not change the Radon domain. The method entails solving an inverse problem that we invert Radon domain by using least square method and reconstruct seismic data at missing spatial locations. This new method is quite efficient and it has an ability to interpolate and denoise (Linear noise) seismic data simultaneously.
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Investigation of the Geothermally Contaminated Area after the Blowouts in Alasehir Using Magnetic and EM Methods
By E. TimurGeothermal activity around city of Manisa in Gediz Graben has been investigated by many researchers and many drillings has been opened in order to produce electricity and heating purposes. In the middle of May, 2012, a geothermal blowout occurred 150 m away from the deep drilling, during 1100 m, in Alkan village of Alaşehir resort in city of Manisa. After that, 4 big blowouts happened at the same area and hot water had been diverted to Alkan stream for almost 4 months. In this study, it was intended to determine contaminated area by using magnetic susceptibility measurements for the surface and VLF-R method for underground layers. All of the susceptibility values were mapped and contaminated areas was clearly defined on the surface using 346 data points. Besides, VLF-R studies were carried out along 18 profiles each of a length of 170 m at three different frequencies with a station spacing of 5 m. Laterally constrained two layer inversion was applied to each station and in addition to the inversion of all profiles for each frequency, all lines were stacked and 2-D views of the possibly contaminated (low resistive) zones which are covering approximately 35000 m2 were obtained.
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Geophysical Investigation for a Geotechnical Project Prior to the Construction of an SME Park
Authors G. Apostolopoulos, M. Lionis, S. Baltas, G. Amolochitis, K. Leontarakis and P. KofakisAn area, near Chania (Crete Island) is planned to be a place of an SME Park with roads and buildings of low industrial activity. A geotechnical survey is needed along with the design of the park. In the frame of the geotechnical project a geophysical survey was planned in order to detect the stratigraphy and possible local features (voids or loose zones) which will further help in positioning additional to the existing boreholes and the design of the park. The relief of limestone top along with confined zones of cracked limestone and the thickness of surface layer with loose material have been detected explaining the presence of the observed land subsidence. Pole-dipole array with the use of MOST technique for the ERT profiles and GPR profiles have given valuable information for the geologists and civil engineers needs. New boreholes have been positioned after the geophysical survey with their sampling confirming the geophysical results.
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Forecasting the Location of Future Earthquakes Based on the Pattern Informatics in the Western Anatolian Part of Turkey
More LessMain goal of this study is to create a forecast map based on the pattern informatics. The composite forecast method is applied for creating potential maps for future strong earthquakes for the forecast time period from January 1, 2013 to January 1, 2023 in the Western Anatolian part of Turkey. Earthquake catalogue containing 71914 earthquakes with magnitudes between 1.0 and 6.7 since 1970 is compiled from Kandilli Observatory and Earthquake Research Institute. The earthquakes of magnitude equal to or larger than the lower cut-off magnitude Mc=3.5 with depth shallower than 40 km dated from January 1, 1970 to January 1, 2013 are selected for the analyses. The combined forecasting map is prepared in order to detect the location of future strong earthquakes in the Aegean Extension region of Turkey during the time period January 1, 2013- January 1, 2023. Some forecasted areas on the Western Anatolian region are detected: around Simav and Soma grabens, junction of Gediz, Kücük Menderes and Büyük Menderes grabens, including Acıgöl, Dinar, Çivril faults and Sandıklı-Dombayova grabens, around Marmara, Köyceğiz, Fethiye faults, around Aliağa-Dumlupınar faults.
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Deformations and Seismicity in the Region of Mirovo Salt Deposit, Bulgaria
Authors D. Dimitrov, I. Georgiev, L. Dimitrova and E. BotevSome results from the geodetic and seismological monitoring of a part of North-Eastern Bulgaria are presented. To evaluate the deformations in the region of Mirovo salt deposit we apply the precise method of permanent survey of displacements using GPS technology. The results of this monitoring show the velocity of displacement for the last 3 years of 6 permanent GPS stations confirming that the seismicity in Provadia region can be considered as “inductive seismicity” related to the intensive exploitation of Mirovo salt deposit. Generally, recent crustal motions in North-Eastern Bulgaria obtained by GPS data analysis reveal identical and no significant residual horizontal velocities relative to Eurasia. Only one point (st.Provadia) located in the central part of the region of interest shows a realtevely higher velocity (especially the vertical velocity) for the last years.
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Crustal Motion Monitoring in Bulgaria and Surrounding Regions by Permanent GPS Array
Authors I. Georgiev, D. Dimitrov and E. BotevGPS data from permanent sites in Bulgaria and the Balkans are used to monitor crustal motions and to constrain the regional geodynamics. Data from more than 70 permanent sites in Bulgaria and surrounding regions are processed and analyzed by GAMIT/GLOBK to obtain horizontal velocities. The results show overall motion in south Bulgaria and northern Greece to the south relative to Eurasia increasing from north to south. The horizontal velocities confirm the extensional regime in Southwest Bulgaria and Northern Greece outlying the presence of the South Balkan Extensional Region.
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The Determination of Vanadium in the Geological Samples through the Method of Neutron Activation
By A. DodonaThis analytical method has found a wide use in production field and research, as well as in geology for precise determination, quickly and with low cost for a number of chemical elements, which are in effective minerals. In AlbaniA, this method has started to be used since 1975 for laboratory determination of some chemical elements and meantime this methodology was used and applied for the well conditions. During our work we have had as objective to found such solution, which to be easy, as it were for the complexity of equipment, to be available for its practical mining and with high affectivity.
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Inversion of Magnetic Anomalies Using Affine Transforms of Geometrical Source Models
Authors P.Y. Stavrev and N. KrastevA method of magnetic data inversion is proposed and implemented. The magnetic source body is represented by a basic geometrical figure that undergoes affine transforms. The latter produce a family of figures in the affine space and among them the optimal solution can be found. If the basic figure in a 2D inverse problem is given as a circular one, then the affine family contains ellipsoidal figures. They represent solutions useful as a first approximation to more complicated source models. The model tests show that ellipsoidal solutions allow the magnetization direction, depth of the upper source surface, sizes and slope of the source body to be estimated. The inverse problem solution is stable and unique due to the small number of unknowns (less than ten in 2D problems) and because of the geometrical restriction over the ellipsoidal convex model with homogeneous magnetization. Two field examples from a lend magnetic survey in the area of the Bulgarian Antarctic base station at Livingston Island and from aeromagnetic investigations in the area of SE Bulgarian Black Sea shelf illustrate the effectiveness of the proposed method of magnetic inversion.
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Remotely Sensed Data for Water Volume Assessment in Inoperative Mines
Authors D. Borisova, H. Nikolov, D. Petkov and T. LubenovAbandoned open pit mines create serious ecological risk for the region of their location. This is valid especially for the quality of water since the rainfalls together with underground waters fill the open pit and form water body with different depth. One example for such opencast, inactive copper mine is Medet (Bulgaria). There are many cases reported for water pollution by heavy metals in the rivers running close to this open pit mine after autumn and spring rains. This justifies the need for long term and sustainable monitoring of the area of the water basin of this unused mine in order to estimate its acid drainage. The imaging spectroscopy combined with is-situ investigations is proved to provide reliable results about the area of the water table and the water volume in it. In this study we have investigated historical data gathered by remote sensing which allowed us to make conclusions about the year behavior of this area. The team expects that the results of this research will help in the rehabilitation process of this inactive mine and will provide the local authorities engaged in water quality monitoring with a tool to estimate the possible damage caused to the local rivers.
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Imaging of Karstic Carbonates Using Electrical Resistivity Data at Malia, Crete, Greece
Authors A. Vafidis, H. Hamdan, N. Andronikidis, G. Kritikakis and N. EconomouThis work involves the use of resistivity and borehole data for the delineation of weak zones in karstic carbonates at Malia, Crete, Greece, where two water reservoirs will be constructed. Site M mostly consists of cretaceous carbonates belonging to the Tripolis zone while Site K consists of upper triassic carbonates of the Tripolis zone. Electrical tomography data were combined with seismic refraction and borehole data. Electrical tomography imaged karstic structures of the Tripolis carbonates at sites M and K. A 3D resistivity image was generated by inverting resistivity data collected along parallel lines on a grid at site M. At this site, electrical resistivity imaging delineated fractured and weathered limestone zones whose thickness ranges from 20 to 40 m. 2D ERT images of the northern part of site M indicate a major low resistivity anomaly. The formations at site K are mostly characterized as slightly weathered limestone (H) with higher RQD values (more than 60). The existing voids are small and the fractured zones exhibit limited extent at site K.
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Effect of Datum Definition on Estimated Station Velocities from GPS Solutions - Case study
By K. VassilevaThe effect of datum definition changes on the estimated station horizontal velocity vectors by using Bernese software, version 5.0 have been studied for the case of a Bulgarian GNSS station network. The least squares method with minimum constraint conditions as a method for GNSS data processing has been briefly presented. Five slightly more or less different datums defined by different combinations of involved IGS reference stations have been applied in the combined solutions of GPS data processing. The magnitude of the obtained BULiPOS horizontal station velocities varies from 0,2mm/yr up to 3,8mm/yr. Comparison of the horizontal station velocities shows differences between all five cases almost the same magnitude of 0,4÷0,6mm/yr for the majority of the stations. For the stations with slow movements (0,2÷0,6mm/yr) these differences are comparable with the size of velocities themselves and the effect is significant. The case study of the Bulgarian GNSS BULiPOS network processed by applying the least squares method with minimum constraint conditions shows that changes in datum definition result different estimations of the station velocities and the effect is very important and significant in combined use of velocities from different sources as input data in geotectonic and geophysical investigations and interpretations.
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Assessment of Environmental Conditions Close to Abandoned Open Mines
Authors D. Borisova, H. Nikolov and B. BanushevAs main source of information spectral data from three different sources airborne, field and laboratory measurements are considered. The main assumption is that correlation exists between all mentioned data and this way extrapolation about the soil state can be made over larger regions based on single point measurements. The advantage is that these data are acquired digitally, at the moment there is a large series of them over same regions and they can be easily processed and utilized in various information formats. In order verify of the results gathered from satellite data additional spectrometric measurements of samples from test sites are performed in-situ and in laboratory. The final target is to estimate the damage caused by sample open pit mine to the neighboring soil cover. The obtained results show that the used data and the implemented approach are useful in soil condition estimation and the method proposed is economically attractive for the company responsible for maintenance of the ecological state of the region.
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Regional Variation of the w-Upper Bound Magnitude of GIII Distribution in the Different Regions of Western Anatolia
More LessThe expected maximum magnitudes are estimated for different regions of the Western Anatolian (WA). The whole examined area is divided into 15 seismic regions based on their seismotectonic regime. The database used in this work was taken from different sources and catalogues such as TURKNET, International Seismological Centre (ISC), Incorporated Research Institutions for Seismology (IRIS) and The Scientific and Technological Research Council of Turkey (TUBITAK) for instrumental periods. The technique of Gumbel-III method is applied. By using this method an upper bound to the magnitudes (ω) is estimated. Also, we compared ω and M_max from Kijko-Sellevol method to research any relation between these parameters. We can say that these parameters are clearly relation each other and reflect expected maximum magnitude for 15 source regions in WA. According to ω and M_max computed for each region Aegean Sea, Aegean Arc, Sultandağı and Tatarlı-Kumdanlı Faults and Dinar Graben have highest hazard potential.
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Recent Progress in National Strong-ground Motion Network of Turkey
Authors U. Ceken, E. Tepeugur, T. Kuru, A. Apak, D. Kokbudak, V. Ozsarac, S. Seze, K. Tekin, E. Ates and C. SahinWe present here the last situation of accelerometers where deployed along whole country, Turkey by efforts of the Earthquake Department of AFAD which directly belongs to the Prime Ministry of Turkey. As of May 2013, there are 10 local scale strong-motion networks including Turkish Republic of Northern Cyprus (KKTC), Iskenderun, IzmirNET, etc. Users can directly access to data via the web site of Earthquake Department of AFAD.
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Remote Sensing Techniques in Vegetation–environment Studies
Authors D. Borisova, R. Kancheva and G. GeorgievRecent developments in environmental studies are related to worldwide ecological problems associated with anthropogenic impacts on the biosphere. Pollution is an undesirable product of human activity. Industrial, agricultural, forestry, and transportation all generate substances and by-products that are considered pollutants. Remote sensing technologies are an effective tool in numerous environmental investigations relevant to ecosystems preservation, biodiversity conservation and other problems of global importance. In agriculture, remote sensing is used for assessing plant growth, condition, and for identification of stress situations. This paper is devoted to the study of the impact of heavy metal contamination on species performance and the possibility to detect pollution stress from measurements of plant spectral characteristics. A main goal is to study the relationships between the stress factor and plant spectral features, and to assess the ability of various spectral indicators to detect plant heavy metal-induced stress. Multispectral measurements were performed over spring barley and pea plots subjected to Ni and Cd pollution. Significant correlations were observed between plant bioparameters and different spectral features. Meaningful statistical relationships were established between the heavy metal pollution amounts, plant bioparameters and spectral properties that allow detection and quantification of the stress factor affect on plant performance.
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Method for Modelling of High-resolution Quasi-geoids
Authors Ch. Tzankov, S. Avdev, R. Radichev, S. Dimovski and A. KisyovThis abstract presents a new technique for creating geoids of high resolution and precision. The first step is to find unique and stable models of the mass distribution in Earth’s core, mantle and crust. This is followed by computation of the gravity potential of the optimized models which are used to find the geoid’s surface. The created models consist of finite number of point-masses and the initial data are the absolute values of the gravity acceleration on Earth’s surface. The Gauss-Newton method combined with an additional regularization algorithm is used in order to fulfil the optimization. The approach is tested upon gravity data taken from the GRACE Gravity Model 02 (GGM02C) released October 29, 2004 and published to the public on http://www.csr.utexas.edu/grace/gravity/. Currently, the optimized models enclose 177 point-masses. This gave us the opportunity to compute the European geoid on a 0.5°x0.5° grid with 134 cm accuracy. It’s obvious that by a continuous increment of the number of point-masses the method will not only reach but overtake the current geoid heights accuracy on a relatively simple and economical way. The only obstacle for the method is the higher computational cost of the procedure.
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Preprocessing of Field Spectrometric Data
Authors D. Borisova, D. Petkov, V. Atanassov and G. JelevRemote sensing using geophysical principles begins with the development and design of equipment for performing research of objects remotely and without disturbing their integrity. In geological remote sensing studies the determination of the chemical/mineral composition and the structure of the objects within the field of view of the instrument either obtained in the lab, with a field spectrometer, or with a remote sensor is a main goal. The aim of this study is to present and test the procedure of preprocessing of the field spectrometric data. Field spectrometric studies of rocks were made to collect spectral signatures of different rock types for the reliable detection and identification of their mineral and chemical composition. The experiments are based on major physical principles such as light scattering, absorption of light, and reflection of light in the electromagnetic spectrum (EMS). Field spectral measurements were made with Thematically Oriented Multi-channel Spectrometer designed and constructed in Remote Sensing Systems Department at SRTI-BAS. The spectrometer with increased spectral resolution works in (400-900) nm range of EMS. The results are compared with similar data from spectral libraries. They correspond to the shape of reflectance spectra in the same range of EMS obtained with other spectrometers.
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Electric Resistivity Tomography (ERT) Measurements in Area of an Old Salt Mine
Authors F. Chitea, D. Ioane, C. Marunteanu and G.F. GarbaceaA large number of old salt exploitations are presently abandoned in Romania as a consequence of mine flooding, determining in many cases active subsidence and collapse. The geophysical study carried out in 2012 at Ocna Dej salt mine had as main objective the detailed illustration by means of ERT and VES resistivity data the actual extent of underground voids. The ERT geophysical measurements were executed above the area of the old Iosif Mine, using a multi-electrode resistivity meter (SuperSting R1- AGI). Two ERT profiles 270m long (D1 and D2) have been measured using the Schlumberger, the Wenner-Schlumberger and the Wenner arrays. According to the resistivity distribution the vertical shaft sector was divided in 3 layers:a) a high resistivity layer due to recently added filling material; b)a very low resistivity zone represented by the upper part of an old filling material, impregnated with salty water originating from the salt lens roof and c) an intermediate resistivity layer at the bottom due to more compacted filling material. ERT method proved to be a powerful geophysical technique in locating and illustrating in detail underground voids in mined salt bodies, its higher resolution allowing interpretations for both geotechnical and hydrogeological use.
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On the Seismic Vulnerability of Pernik Region (West Bulgaria)
Authors E. Botev, S. Simeonov and K. HadjiyskiOn May 22, 2012 the seismically quiet Pernik area produced the strongest Bulgarian earthquake for the latest 80 years with Mw=5.6 and maximum observed intensity of VIII degree EMS. Thus the real seismic impact on structures has to be assessed and vulnerability of the local building stock has to be revised accounting for the physical characteristics of this event, the actual response of affected structures and their post-earthquake condition. For this purpose data from the local digital SGM Network of Sofia, that recorded this earthquake, is processed and used to evaluate the characteristics, relevant to aseismic design of structures. Damages induced to buildings in Pernik area by the main event and the aftershocks are investigated on site. They are illustrated and the vulnerability aspects are discussed. Finally implication about the reasons for current vulnerability of damaged buildings in Pernik area is provided.
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A Preliminary Results of Fault Plane Solutions of the Recent Earthquakes in and Around Eastern Black Sea Region
Authors Y. Bayrak, T.S. Irmak, B. Doğan, H. Çınar, Ş. Yılmaz, D. Kalafat, A. Karakaş and E. BayrakThe present study shows preliminary results using the fault mechanisms of small-moderate earthquakes in the Eastern Black Sea Basin and defines relation of fault mechanism with the tectonics. For this purpose, 13 earthquakes which occurred in the time period of 2004 – 2012 were analyzed. Focal mechanisms were determined using focmec algorithm and the analyzed earthquakes characterized a reverse (thrust) faulting mechanism with presence of strike slip component. The earthquakes occurring in the Eastern Black Sea basin and surroundings indicate the active tectonic lines in the region. Additionally, the Greater Caucasus thrust faults with ENE-WSW trend and dipping both south and north directions continue into the sea and the thrust faulting is accompanied with the strike-slip faulting according to the fault plane solutions of the earthquakes. Accordingly, main origin of the earthquakes are associated with the thrust faults related to subduction and accompanied with the secondary strike-slip faults developing in the upper parts of the oceanic crust during the deformation process.
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Terrestrial Photogrammetry in Albania and Its Contribution in Geophysical Researches
By V.D. DinajAlbania is a mountainous Mediterranean country with numerous natural energy resources. There are many rivers flowing from the mountains where seven hydro-power plants have been built. In this paper we present photogrammetric work in an engineering geological-geophysical investigation of the Koman landslide, Shkoder area, Albania. Our ability to make highly precise maps has been crucial to our success. We rely on photogrammetry in general as a key tool to help accurately capture different formations. The photogrammetric project on the state of landslide in Koman hydro power included studies on changes in both banks of Koman dam. The study included work field by taken photographs in a very difficult ground for both banks of dam. Our terrestrial photogrammetry enabled us to capture data from large scale stereo models in preparing digital topographic map (topo map) with high quality and efficiency. CAD drawings were the most effective way to document technical drawings and related information in an organized manner. CAD combined with GIS enables data to be analyzed
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Investigation of Bafa Lake with Seismic and Marine Magnetic Method
By S. EdremitThe surface area of the Bafa Bay is about 75 km², it’s the location above the sea level 5 m, and it’s the deepest part 20-25 m. The Bafa Lake is located at the watery area about 37° 31´ N and 27° 27´ E which is accepted on the international important area list. Besides, the Bafa Lake is very important area for the archaeological case. The scientific data of the Bafa Lake is too limited. For that reason, the geophysical studies are planned on the first step of the project. After completion of this study, the formation and morphology of the lake will be found out by using seismic and magnetic techniques. To perform this study, an equipped research boat with 4-6 m of the length will be used for the marine investigation at shallow water.. At the first step of the study, data acquisition will be completed and according to the methods which are stated on the study that high resolution seismic and total magnetic area measurement performed. In the result, this study will be the first study, especially, for the lakes. Keywords: Magnetic Area, Latmos Bay, Geophysic, Shallow Water, Seismic Studies.
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The Investigation of Geothermal Potential of Gülbahçe Bay(Karaburun Peninsula) by Single Channel Seismic Reflection Dat
Authors Z. Altan, N. Ocakoglu, D. Dusunur-Dogan and D. YagcıIn this study, a N-S trending, internal bay that geothermal potential of Gülbahçe Bay, which is between the Gulf of İzmir and Karaburun Peninsula, is aimed to investigate by seismic reflection data and thermal modelling. The area of study locates at the most western part of Gediz Graben which has a highly geothermal potential. Even though, many previous studies have investigated geothermal system and potential reservoirs onland in this region, the continuation of these reservoirs under the sea has not been researched enough. For this purpose, single channel seismic reflection data was conventionally processed and interpreted and related thermal and fluid flow modeling were performed to understand both major tectonic features which delineate the possible ground water flow paths and geothermal capacity in the gulf. The results show that hot water goes out on N-S trending active strike slip faults along, commented on two lines on E-W trending. At the reflection levels along the vertical axis seen rising structures have been interpreted as the hot water outflow. This outflow zones are also consistent with the thermal modeling results.
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Thermal Conditions for Geothermal Energy in Transcarpathian Depression
Authors D. Majcin, R.I. Kutas, D. Bilčík and V. BezákThe contribution presents the results of our cooperative geothermal works in the Transcarpathian depression - very perspective region for exploitation of geothermal energy both for Slovakia and for Ukraine. The activities were focused on interpretation of temperature and heat flow data, geothermal modelling results and relations of the thermal state of the lithosphere to the tectonics in the region under study and surrounding geological units. These results and additional modelling works afforded us the opportunity to construct the terrestrial heat flow density map and maps of the temperature distribution in various depth levels and consequently to analyse the thermal conditions for the exploitation of geothermal energy in separate basins of the Transcarpathian depression.
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3D FE Modelling of Gravity-driven Rock-deformations for the Estimation of Cavity Effect and Sensitivity
More LessIn this paper authors performed 3D finite element modellings in order to analyse gravity driven rock deformations, as well as the effect of the cavity system embodying the equipment, and the sensitivity of planned or existing equipment arrangements. The cavity effect is one of the most important factors influencing the absolute accuracy of geodynamic and gravity-driven (tidal) deformation measurements. Data sets compiled from different observatories should be improved by the estimation of this effect, in order to be conformed and processed together. Results of a method development are presented where the sensitivity and the cavity effect rate are qualitatively and quantitatively characterized by the proposed formulas (parameter fields), based on the output displacement matrix of the 3D FE modelling. As an application example finite element modellings were carried out in order to estimate the influence of the complicated cavity system surrounding the Matyashegy Gravity and Geodynamical Observatory of the MFGI, Budapest.
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Determination of Earthquake Early Warning Parameters τc and Pd for City of Istanbul
Authors S. Turan, S. Karabulut and O. ÖzelEconomic, social and society damages caused by earthquakes is an important issue for developed or developing countries. Generally, there are three main reasons for damage caused by the earthquakes. These are the properties of earthquake sources, site effect and the structural properties of engineering buildings. Especially, when we interest the properties of earthquake sources, two different solutions of this issue can be produced such as short-and long-term. Early warning is quite a short-term of them. Principal aim of this study is evaluation for a potential damage of Istanbul after a disastrous earthquake and using of earthquake early warning system for this city. For this purpose, we used the peak displacement and velocity amplitudes of the first 3-sec of the P wave. The vertical component records was used to analysis and applied high-pass filtered at 0.075 Hz. The relationship between the peak initial-displacement amplitude (Pd) and the peak ground-motion displacement (PGD) and velocity (PGV) at the same site. When Pd 0.5 cm, the event is most likely damaging. If Pd is combined with the period parameter c determined in an earlier study, then cxPd provides an even more robust parameter for assessing the potential for damage.
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Tectonic Implications of Microseismic Activity and Fault Plane Solutions around Izmir City
Authors O. Polat, E. Gok, I. Ozen, C. Mihbuken, M. Kececioglu and U. CekenWestern Anatolia is one of the most seismically active and expeditiously extending regions in the world. The large-scale deformation in the Western Anatolia is dominated by the collision of the African and Arabian plates with Eurasia. This collision causes a westward migration of the Anatolian block from the east to the Aegean Sea in the west. Izmir city is the capital of Aegean region, and also 3rd biggest city of Turkey with its more than 4 millions inhabitants. This study aims to reveal present micro-seismic activity and seismotectonic features obtained from a local-scale accelerometric array.
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Modeling Microgravity and DC-resistivity Response of a Longwall Mine at Soma-Darkale Coalfield
Authors E. Buyuk and A. KaramanAbstract. Estimating the footprint of a coal panel becomes important to resolve conflicts related to the adverse effects of longwall coalmining. The conflicts may be about permit boundary infringement, mitigating subsidence-induced hazard, or in some cases, avoiding the old production fields while projecting a panel and panel orientations. The utility of gravity and dc-resistivity methods provide valuable information when evidence such as fracturing and/or pre-, and post-subsidence deformation profiles are insufficient. Coalmine subsidence increases the secondary porosities of the overlying strata, which causes water-level drop because of increasing storage, and reduces the densities of the overlying rocks. With this study, we develop a 3-D gravity modeling code to account for the factors that are likely affect the geophysical measurements. We also address the factors that are likely violating the fundamental assumptions of the dc-resistivity measurements obtained over a subsided production panel. The geophysical data used in this study were acquired over a longwall mine panel at Soma-Darkale Coal field.
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A Tool for Analysing Depth Resolution in Potential-field Inversion
Authors V. Paoletti, M.F. Hansen, P.C. Hansen and M. FediA careful management of the ambiguities and errors in potential field inversion is crucial for obtaining reliable information about the source distribution with respect to depth. In this paper we introduce a tool, the ApproxDRP, which is based on an approximation of the singular vectors obtained by the iterative Lanczos bidiagonalization algorithm. This tool allows a computational/visual analysis of how much the depth resolution in a potential-field inversion problem is influenced by the way the problem is discretized and regularized. Since the ApproxDRP is based on an iterative method, it is suitable for large-scale problems. We show that when used in combination with a plot of the approximate SVD quantities, the ApproxDRP may successfully show the limitations of depth resolution resulting from noise in the data. This allows a reliable analysis of the retrievable depth information and effectively guides the user in choosing the optimal number of iterations, for a given problem.
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Waste Disposal Sites Investigation by the Use of Electrical Resistivity Tomography
Authors G.N. Vargemezis, P. Tsourlos, G. Tsokas, I. Fikos, N. Diamanti and A. StampolidisManagement of waste disposal is a major issue that authorities had and still have to deal with. The construction of landfills used to be the main way to manage the great volume of waste. At the present time, the construction of sanitary landfills is the dominant option in Greece, while old waste disposal sites where no protection standards had been followed still exist. In both cases, geological and hydrogeological setting of these areas is of a major importance. In this paper, two cases studies are presented. One case refers, to the active sanitary landfill of Thessaloniki where during the remediation of a new cell, underground water has been found. This was a major problem for the construction of the new landfill since water flow beneath the geomembrane can be destructive. The detection of the flow path and the confrontation of the problem was very important. Resistivity survey allowed the mapping of the underground water flow and appropriate measures have been taken according to the suggestions of the geophysical results. In the second case, an old waste disposal site has been investigated since outflows of leakage occurred. The flow paths of the leakage have been detected and remediation measures have been suggested.
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Determination of Uranium, Thorium and Potassium
By Ema DodonaGamma spectrometric method is used for determination of U, Th and K in laboratory and field conditions. For this purpose a gamma spectroscopic instrument GAD-6 with NaI detector was used. The study and experimentation of the main factors like geometry and calibration which influenced in the gamma spectrometry measurements was performed. Calibration procedures were carried out based in rock samples preparation, recommended by IAEA. Through the mentioned methods were analyzed thousand of rock samples for the U, Th and K content determination with great precision and low cost.
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A Review of the Scientific Studies Published in the Radiogeochemical-Radiometric Bulletins during 1949-2000 Years
By A. DodonaThis bibliography is prepared for the sake of 100 anniversary of radioactivity discovery by H. Becquerel about the Uranium (1896), and the first perception of Radium done by Pier & Marie Curi (1898), whom in relation with this were honored with Nobel Reward (1903). The philosophy of such discover remind us A. Flemings saying: “Never left apart the things that seem to be strange or uncommon, often they may be false alarm, but may be even the key of an important truth”. Instead its value and importance is expressed in significant saying of A. Einstein “,,Radioactivity phenomena representative most revolutionary force of technical progress since from the time of the fire discovered by prehistoric man”.
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Basin Evolution and Hydrocarbon Plays in Albania
More LessA new geodynamic model based on structural and kinematic observations is presented here that predicts that anticlockwise rotation of the Apulia foreland along with its uplifted promontory in the southwest of Albania provided a buffer stop for the incoming ‘train’ of the Ionian basin thrusts during the Oligocene to Pliocene. A regional shear couple was formed between the hinterland and the buffer stop which was accommodated by strain partitioning along the strike. The Ionian basin thrusts were uplifted and exhumed in the south as they buttressed towards the promontory, while propagating freely in the north towards the foreland and overlain by Durresi foredeep basin during the Miocene – Pliocene.
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The Influence of the Shear-wave’s Velocity Variation on the Response of the Geotechnical Models - a Case Study
By E. VeseliIt is well known that the soil response to the earthquake motion depends on the various parameters describing the layers over the bedrock. We analyze one of the geotechnical models of the Tirana City and try to find the influence of the shear-wave velocity variations over the sedimentary cover on this response. We compare the original model formulated at the end of 80-s in terms of VS with new measurements of this parameter carried out through down-hole and MASW techniques, keeping on the same time other parameters constant. The earthquake motion was propagated through the same column, but with three different VS values for the uppermost part of the section. A different pronounced response was noted for each case, indicating that modification of the old model’s VS parameter on a site-by-site case should be carried out before using the soil response analysis data for design purposes.
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Late Pleistocene – Holocene Seismic Records of a Sand Ridge at the Southern Exit of Istanbul Strait, Turkey
More LessThe stratigraphic setting and morphotectonic development of a wedge-shaped sand ridge, 2 km long and 600 m wide, on the southern approaches of the Strait of Istanbul has been investigated using high resolution chirp data. On a ravinement surface it is evolved during the post-glacial sea-level rise in the Sea of Marmara (late Pleistocene-early Holocene). The dynamics of sea bottom sediments, estimated from net sediment transport pathways by applying grain trend analysis, implied that the shallow depression channel behind the sand ridge is one of the much suitable depositional environments.
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Geotechnical Problems Caused by Unknown Cellars
More LessSome months ago there was a collapse in a public park in Budapest, Hungary. On the location called Kőbánya the limestone was covered by 10-30 m of good quality clay. For that reason clay was excavated in general in open-pit mines while limestone was exploited in quarries and in underground tunnels as well. The main reason of the accident was consideret to be the collapse of an unknown tunnel or cellar. The surroundings of the void was investigated by different gophysical metods to find the reason of the event and to map the potencial location of latter collapses. DC geoelectric, GPR, seismic diffraction and tomogrphic methods were applied. The findings were proven by drillings and CPT soundings.
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Determination of Soil–structure Response by Using Microtremor Measurements in Bornova, İzmir (Turkey)
Authors E. Pamuk, S. Turan, F. Onsen and S. KarabulutUnderstanding the seismic behavior of buildings during the earthquakes is very important. Microtremor measurements are required to estimate the resonance frequency of soil and buildings . HV spectral ratio technique is widely used in urban environment to assess the fundamental frequency response of the ground. Therefore, the H/V spectral ratio was calculated with this method. The measurements were taken inside the building basement floor, third floor, fifth floor and eighth floor. 150 m on southwest of the building is selected as the garden point. It is noticed that if the number of floors increases, predominant frequencies decrease and H/V ratios increase. The amplitude spectral analysis of the all points was carried out to determinate the spectral characteristics of soil and building. The amplitude spectrums of all data were compared with each other. It points that significant increasing of amplitude values are interested with increasing of the floor numbers. Therefore, the highest amplitudes are obtained on the top floor. The amplitude values of horizontal components are greater than vertical component at the floors 3rd ,5th and 8th. However, we observed similar values at basement point and outside point at all components.
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Site Condition Mapping using Topographic Slopes
More LessWe investigate the possibility of adaptation a new method for large scale assessment of seismic site conditions and amplification, by using maps derived from topographic data, making the technique quick and cost effective. The maps uses topography slopes as a proxy for site conditions, based on its close connection to the results of shear wave velocity measurements proved by previously accomplished correlation calculations. The technique was investigated on a test site in Hungary by using SRTM 3 sec maps and VS,30 (average shear wave velocity down to 30 m) results of surface wave measurements carried out previously. Our results show that the measured and calculated VS,30 values are close to one another, but in case of the test and similar areas (characterized by consolidated alluvial deposits) the velocity values scatter around the important boundary level (360 m/s) of “B” and “C” categories. Consequently some refinement of correlation and involving geologic data can be necessary and useful for a more accurate classification.
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Modelling of the Shallow Structures of Cappadocia Region by Gravity Method
Authors Ö. Bektaş, S. Koşaroğlu, A. Büyüksaraç and A. AteşCentral Anatolia and the surrounding area for many researchers engaged in studies concerning the origin of the tectonic and volcanic activities are examined, which is composed of tectonic units in Cappadocia is different based on the findings, many researchers have obtained different results. In this study, using a 2.5-D and 3-dimensional models of gravity data and the work area made of low-density, loosely defined thickness of the upper structure. Working in the field surveys conducted in recent years, volcanic studies, hydrocarbon and geothermal research, field research has revealed the need to describe the relationship between deep and shallow structure. In addition, studies so far out in the study area is shallow and low-density units on the caldera is showing some of the basic approaches to feature-reach, within the scope of this thesis are among the targeted results.
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Direct Targeting of VMS through Amplitude Consistent Seismic Imaging
Authors S. Yavuz, J. Kinkela, A. Greenwood, M. Penney, V. Araujo, R. Neto, A. Dzunic and M. UrosevicBased on physical property measurements of core samples and the often observed difference in elastic properties from these there should be a significant difference in seismic amplitude between mineralisation and the surrounding host rocks. These results indicate that relative amplitude preservation processing may be of importance in the use of seismic data for the targeting of mineral resources, particularly in the case of massive ores. Such ‘true relative amplitude’ processing is not easy to achieve due to intrinsically low signal to noise ratio in hard rock environments, complex 3D geology, steeply dipping structures, high seismic velocities and often patchy and poor reflectivity. To help reduce the ambiguity in targeting and increase the likelihood of success we have worked on careful re-processing of 3D seismic data with the application of true amplitude preservation. We compare the anomalous amplitude zones that are related to massive sulphide bodies using a true amplitude seismic cube and a conventionally processed cube with the application of AGC (automatic gain control). A higher level comparison is conducted after seismic calibration with boreholes. The zonation and precision of targeting is discussed in this paper.
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Time-frequency Analysis of Georgia Earthquake (25 December 2012)
More LessSeismic waves that observed in earthquake records are non-stationary typical. To better understand the structure of the seismic signals, not only is enough to examine changes at time domain, also frequency domain is shows a component characteristics of the signal important. Therefore in recent years, different time-frequency analysis methods are used extensively. Time-Frequency analysis is suitable for non- stationary signal analysis and processing. Time-frequency analysis contains a signal in both time domain and frequency domain at the same time. In this study we applied and compared a linear and a quadratic two different time-frequency analysis methods short-time Fourier transform and Wigner-Ville distribution in December 25, 2012 Georgia earthquake record. As a result of this study, short-time Fourier transform method gave better results than the Wigner-Ville distribution.
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Resistivity (ERT) Prospection in Tropaeum Traiani Roman City
More LessTropaeum Traiani archaeological site consists of ruins of an ancient city and a triumphal monument built after a victorious Roman campaign against Dacians during the winter in 102 AD. Civitas Tropaensium started as a castrum and became a municipium around 200 AD. The main archaeological interests presented as geophysical tasks to the geophysical prospection were the remnants of the first Roman stage of the city (first century AD), impossible to excavate and directly study due to the legal protection of the shallowest remains of ancient constructions, dating from the second Roman stage of the city (started during Constantin the Great, IVth century AD). Geophysical profiles of Electric Resistivity Tomography (ERT) were carried out in the area of Basilica Forensis and along Via Principalis. The two levels of high resistivity anomalies illustrated on the Via Principalis ancient street were interpreted as remnants of limestone pavement and constructions walls, remains of the second stage of the city, and of the first stage respectively. The resistivity survey inside Basilica Forensis shown also two levels with high resistivity anomalies, interpreted to be associated with the basilica inner pavement and its infrastructure.
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Diffraction Imaging Using Plane-wave Destructor Filters in Common-depth Specularity Gathers
Authors T.J. Moser, I. Sturzu, A.M. Popovici, I. Musat and N. TanushevSeismic diffraction imaging is recognized as a rapidly emerging technology with great potential to reduce exploration and production risks and increase recovery, for conventional reservoirs as well as unconventional resources such as shale gas. The idea behind diffraction imaging in a pre-stack migration framework is to apply a weight factor inside the migration loops, which attenuates events that satisfy Snell's law of specular reflection, while preserving diffractive events that do not satisfy Snell's law. Here we further develop an approach, called specularity gathers, to construct the weight factor in a very efficient way. We introduce a method to filter the specular energy from specularity gathers in order to obtain diffraction images. The use of a filter like plane-wave destructor enables an automatic algorithm, but leaves the option for interactive updates based on interpretation input as well. Further development of this method will help in advancing diffraction imaging technology.
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Some Results for 3D Gravity Inversion in Parallel Systems
Authors N. Frasheri, S. Bushati, A. Frasheri and B. CicoThe aim of the paper is presentation of some results obtained for the 3D gravity inversion in high performance parallel computer systems (HPC). Calculations were based on CLEAN algorithm parallelized with OpenMP and MPI using HPC capacities offered by FP7 project HP-SEE. Scalability of runtime in terms of model sizes and number of computing cores was analyzed. The quality of inversion was evaluated for single and two body models, and concrete tests with field data were carried out. Runtime analysis results matched theoretical expectations for the order of magnitude of calculation time O(N^8) where N represents the linear size of the geosection, and permitted an evaluation of effective runtime for small and medium models. Two modified least squares schemes were applied for the inversion of multi-modal anomalies and respective errors compared. The link between symmetries of geosections and respective anomaly approximation errors was observed. Obtained inverted geosections are characterized by distinguished contrast of mass density between anomalous bodies and surrounding rocks. But more work is required to deal with multi-body geosections (multi-modal anomalies) to reduce the lack of discrimination capacity of the algorithm for in-depth bodies.
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Preliminary Results from DANA Array on the Crustal Structure of the Western Segment of NAF
Authors N. Turkelli, M. Kahraman, S.A. Poyraz, M.U. Teoman, S. Rost, G.A. Houseman, D. Thompson, D. Cornwell, M. Utkucu and L. GulenThis study focuses on upper crustal studies such as earthquake locations (especially micro-seismic activity), moment tensor inversions and receiver function analysis. Accurate earthquake locations will eventually lead to high-resolution seismic images of NAF including both the northern and the southern branches in the upper crust.In this study, 722 earthquakes within the time period of 09 May – 17 September 2012 were located. Furthermore, the crustal structure beneath the DANA Array is investigated using receiver functions obtained from the teleseismic recordings from a total of 73 broadband stations. Calculated Moho depth beneath the most of stations is between 33 and 36 km.
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Seısmıc Rısk Analysıs of Sapanca Dıstrıct
By M. SaygiIn and around the lake sapanca the environmental impact of earthquakes and seismic risk analysis
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Exploration of Buried Cannons Using Magnetic and GPR Methods in Canakkale, Turkey
Authors A. Büyüksaraç, C.Ç. Yalçiner, Y.C. Kurban, M.İ. Topçu and B. SayilirThe old Ottoman fort of Kumkale lies 5 km from the ruins of ancient Troy and 45 kilometres south of Çanakkale, Turkey. The fort dates from the 17th century and was built as part of the outer defences of the Straits. From the Kumkale area there are fine views to Gallipoli Peninsula and Dardanelles, and throughout the campaign Turkish batteries hereabouts bombarded Allied positions at Helles. The French fleet had stationed in front of Kumkale shore, Çanakkale, during World War I on 25th of April, 1915. Turkish Cannons in the batteries bombarded the fleet, however, they were not be able to complete their duty. French soldiers landed under protective bombardments of the navy targeting Kumkale and Orhaniye. After that all cannons were destroyed by allied soldiers. The ruins of the cannons were buried and disappeared at site. However, army has plans of the batteries and places of them were approximately known by historians. That’s why a geophysical survey campaign was planned to find the old cannons. In the frame of geophysical survey, magnetic and GPR methods were applied. Figure 2 shows profile map for both of these methods. Of course magnetic method was more successful in prospecting the heavy and huge iron cannons.
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