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Near Surface 2004 - 10th EAGE European Meeting of Environmental and Engineering Geophysics
- Conference date: 06 Sep 2004 - 09 Sep 2004
- Location: Utrecht, Netherlands
- Published: 06 September 2004
81 - 100 of 132 results
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Application of the GPR Method to the Diagnostics of Building Structures in the Case of Buildings of Historical and Cultural Importance
By M. ŽivanovicP009 APPLICATION OF THE GPR METHOD TO THE DIAGNOSTICS OF BUILDING STRUCTURES IN THE CASE OF BUILDINGS OF HISTORICAL AND CULTURAL IMPORTANCE 1 INTRODUCTION Ground penetrating radar (GPR) is a geophysically-based method which has growing applications in civil engineering for the determination and assessment of the condition of the elements of building structures. The main advantage of GPR measurements over other research methods is the fact that this method is non-destructive. Furthermore the GPR method can be used to investigate the whole volume of building elements and measurements can be repeated after a certain time. The paper contains a description
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Seismic CPT Measurements
Authors P. Dietrich, T. Fechner and E. NolteP010 SEISMIC CPT MEASUREMENTS 1 For new constructions or reconstructions a comprehensive description of the ground is needed. This includes knowledge about the site history and long-term loads the soil was exposed to (e.g. consolidation creeping maturing). In this context the prediction of ground deformation is one of the most important topics in geotechnical engineering where the numerical calculations require parameters like soil stiffness. In most cases local site tests such as Cone Penetration Tests (CPT) and load bearing tests as well as laboratory tests are used to estimate soil stiffness. However due to the assumption of homogeneity of subsurface
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On the Use of Two- Vs. Three- Dimensional Transformation and Interpretation of Potential Field Anomalies
More LessP011 ON THE USE OF TWO- VS. THREE- DIMENSIONAL TRANSFORMATION AND INTERPRETATION OF POTENTIAL FIELD ANOMALIES Introduction 1 G. FLORIO 1 M. FEDI 1 AND F. CELLA 2 1 Department of Earth Sciences Università di Napoli ‘Federico II’ Largo S. Marcellino 10 80131 Napoli ITALY 2 Università della Calabria Rende (CS) ITALY High resolution potential field surveys are routinely conducted measuring data along a number of closely spaced profiles conveniently oriented that allow compiling maps of the field in the study area. The acquisition of the data along the lines is at a very close sampling step thanks to the
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Apparent Strike Resistivity Imaging
More LessP012 APPARENT STRIKE RESISTIVITY IMAGING Abstract 1 High resolution fast and reliable field and interpretation techniques are needed for shallow geophysical investigations. When resistivity investigations are carried out it is well know that ground inhomogeneity and anisotropy can produce strong orientational effects that can add further noise to field data. Several field techniques have been proposed to study and overcome these effects such as the square array and its modified version the crossed square array of electrodes. However little or limited interpretation material is available for these nonconventional field techniques and only a few case studies have been reported in
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Structural 2-D Inversion of Resistivity Data
Authors P.J. Pujari, W.P.H. Knoops, P.V. Ditmar and J.W. BredewoutP013 STRUCTURAL 2-D INVERSION OF RESISTIVITY DATA P.J. PUJARI 1 W.P.H. KNOOPS 2 P.V. DITMAR 3 AND J.W. BREDEWOUT 4 1 1 National Environmental Engineering Research Institude Nagpur-440 020 India 2 Geocom-Sialtech 3 Delft University 4 Utrecht University Summary An algorithm has been developed for structural inversion of 2-D resisitivity image profiling (RIP) data obtained over a layered subsurface. Contrary to smooth inversion our algorithm aims at inversion for the geometry of the model when the properties (layer resistivities) are known a priori. In smooth inversion the result is a model of the subsurface in which the resistivity varies continuously
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Elements of Calibration and Data Interpretation of EMI Sounding Device EMS
Authors E.V. Balkov, M.I. Epov, A.K. Manstein and Y.A. MansteinP014 ELEMENTS OF CALIBRATION AND DATA INTERPRETATION OF EMI SOUNDING DEVICE EMS 1 ⎧rotH = ( σ + iωµε ) E ⎨ ⎩ rotE = −iωµ H E.V. BALKOV M.I. EPOV A.K. MANSTEIN Y.A. MANSTEIN Institute of Geophysics Siberian Branch of Russian Academy 630090 Russia Novosibirsk Koptyuga str 3 Present work is devoted to development of mathematical apparatus for calibration data processing inversion and visualization of electromagnetic induction sounding device EMS. Mathematical algorithms results of modeling and its practical use will be presented in the contribution. Introduction Electromagnetic induction frequency sounding device EMS (Figure 1a) is the portable shallow-depth prospecting
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Hydrogeophysical Investigations of a Cork Oak Habitat, Portugal
Authors U. Werban, S.A. al Hagrey and A. IsmaeilP015 HYDROGEOPHYSICAL INVESTIGATIONS OF A CORK OAK HABITAT PORTUGAL 1 Summary During experiments at a cork oak site in Portugal heterogenous soils including root zones were studied by geoelectric georadar and TDR methods in respect of analyzing the water budget. An empirical relationship between moisture content on one side and resistivity and GPR velocity on the other side are established and used for studying the hydrologic situation in the investigation area. Also resistivity technique was used to image the internal structure of tree trunks. Introduction and objectives The global increase of water use is faced by a limited availability in
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Dual-Frequency Subbottom Profiling for the Evaluation of Safety of Offshore Structures
Authors V.P. Lisin and Y.P. BezrodnykhP016 DUAL-FREQUENCY SUBBOTTOM PROFILING FOR THE EVALUATION OF SAFETY OF OFFSHORE STRUCTURES P-wave velocity m/s 1 Summary The application of dual-frequency continuous subbottom profiling for the evaluation of the offshore structure safety conditions during their installation and exploitation is considered. The developed set of equipment is used during the stages of site investigations for the construction of offshore drilling platforms and underwater pipelines and their subsequent geological-geophysical monitoring. The profiling modes in different frequency ranges are used for the identification and outlining of components of the geological environment that are hazardous or unfavourable for offshore structures. In combination with geotechnical
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Investigation of Pollution Resulting from Storage of Deicing Salt by Geophysical Measurements
Authors K. Martens and K. WalraevensP017 INVESTIGATION OF POLLUTION RESULTING FROM STORAGE OF DEICING SALT BY GEOPHYSICAL MEASUREMENTS Abstract 1 A municipal plot with storage of deicing salt and a storage of fuel oil (above ground) is abandoned. All the remaining buildings are removed so the plot is fallow. By means of geophysical investigation the extension of pollution caused by dissolved salt will be determined. 1. Introduction The groundwater is polluted at a former storage of salt used for road deicing. The pollution is caused by infiltration of dissolved salt that reaches the groundwater table. The storage has been removed since a few years. So
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Integrated Study of the Sinkhole Development Site Using Geophysical Methods
Authors M.G. Ezersky, I. Bruner, S. Keydar, P. Trachtman and M. RybakovP018 INTEGRATED STUDY OF THE SINKHOLE DEVELOPMENT SITE USING GEOPHYSICAL METHODS 1 EZERSKY M. 1 BRUNER I. 2 KEYDAR S 1 TRACHTMAN P. 1 AND RYBAKOV M. 1 1 Geophysical Institute of Israel P.O.Box 182 Lod 71100 Israel e-mail: [email protected] 2 Ecology and Engineering Ltd. Igal Alon Str. 65 Toyota Towers Tel-Aviv Israel [email protected] This paper presents methodology that uses a combination of the high resolution seismic diffraction reflection refraction CVES GPR and Microgravity methods to study the structure and properties of the shallow subsurface at the sinkhole development site in Nahal Hever southern area (Dead Sea shore) in Israel.
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An Algorithm for the Numeric Combination of Geophysical Mappings of Archaeological Sites
More LessP019 AN ALGORITHM FOR THE NUMERIC COMBINATION OF GEOPHYSICAL MAPPINGS OF ARCHAEOLOGICAL SITES Summary 1 In this paper we suggest an algorithm for numeric combination of different geophysical mappings based on archaeological surveys. This algorithm is discussed on the basis of magnetic electric and electromagnetic surveys within a hethitic town in Central Anatolia Turkey located at the top of the Kerkenes mountain. The anomalies caused by archaeological structures can be emphasized by numerical combination of different geophysical mappings and the influence of geological structures can thereby be minimized. The archaeological interpretation is improved. Introduction H. VON DER OSTEN-WOLDENBURG Landesdenkmalamt Baden-Wuerttemberg
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Exploring Ancient Topography by Seismic Tomography – The Case of the Chatby Cemeteries in Alexandria (Egypt)
Authors L. Polymenakos and S. PapamarinopoulosP020 EXPLORING ANCIENT TOPOGRAPHY BY SEISMIC TOMOGRAPHY – THE CASE OF THE CHATBY CEMETERIES IN ALEXANDRIA (EGYPT) L.POLYMENAKOS S.PAPAMARINOPOULOS Abstract 1 The paper discusses the application of seismic traveltime tomography as employed to the exploration of ancient topography and the search to ancient tombs within a modern urban framework. The application was made in the cemeteries of the Chatby area in central Alexandria Egypt. Knowledge of ancient topography is of great importance in the understanding of subsurface structure related to past human processes and can be a valuable aid in archaeological and engineering surveys and site investigation. The cemeteries at
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Geophysical Characterization of a Coastal Acquifer – Inital Results
Authors H.R. Maurer, S. Friedel, D. Jaeggi and S. LoewP021 GEOPHYSICAL CHARACTERIZATION OF A COASTAL AQUIFER – INITIAL RESULTS 1 H.R. MAURER S. FRIEDEL D. JAEGGI S. LOEW ETH Zürich 8093 Zürich Switzerland SUMMARY In an investigation of a coastal aquifer on the island of Mallorca (Spain) seismic cross-hole and geoelectrical single-hole data have been collected processed and tomographically inverted. Variations in seismic velocity and electrical resistivity did not correlate within the fresh water layer. In contrast seismic velocities and resistivities both decreased in a uniform manner within the underlying fresh water-salt water transition zone and upper part of the salt water layer. In these regions resistivities were primarily
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Detailed Geophysical Study of Glaciofluvial Aquifer at Kempele, Western Finland
Authors T. Valjus, O. Breilin, H. Vanhala and J. LehtimäkiP022 DETAILED GEOPHYSICAL STUDY OF GLACIOFLUVIAL AQUIFER AT KEMPELE WESTERN FINLAND Summary 1 For mapping a deep glaciofluvial esker aquifer at Kempele Western Finland an integrated study including ground and airborne geophysical measurements and drill core data was carried out. The geology of almost flat study area is characterized by a one-kilometer thick graben structure (Muhos formation) filled by Vendian - Jotnian (0.6-1.2 Ga) shales arkose and conglomerates. Underlying crystalline bedrock consists mainly of Archean and Proterotsoic granitoids and shales. The uppermost loose overburden is 10 to 100 m thick and consists of Quaternary glacial sediments mainly till gravel sand
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Cross-Hole Electrical Tomography on a Dam
More LessP023 CROSS-HOLE ELECTRICAL TOMOGRAPHY ON A DAM SUMMARY 1 A dam of a water reservoir is investigated by cross-borehole electrical tomography and a geoelectrical survey on the slope. Since the boreholes are dry a new type of pneumatic borehole electrodes was successfully applied. The resolution of different electrode arrays has been investigated. The pole-pole-configuration which provides the largest number of readings has proved to generate the most reliable vertical resistivity cross-section. The resulting images of the other configurations are disturbed by artifacts. The vertical resistivity section of the surface profile can be well extended to greater depth by the results
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Multi-Offset GPR Profiling at the Aquifer Test Site Tettnang (SW Germany)
Authors A. Becht, E. Appel and P. DietrichP024 MULTI-OFFSET GPR PROFILING AT THE AQUIFER TEST SITE TETTNANG (SW GERMANY) Abstract 1 Multi-offset ground-penetrating radar (GPR) data were collected in a glacial delta environment with 20-30° dipping gravel beds (aquifer test site Tettnang Southwest Germany). We apply pre-stack processing techniques and normal moveout velocity analysis in preparation of stacking. Stacked GPR sections show significant improvements in depth of investigation and reflector imaging over a standard constant-offset section. This allows a more reliable interpretation of geological structures. The resolution of shallow reflectors in the stacked section is improved by muting of wide-angle reflected energy. Simultaneous acquisition of four channels
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Fresnel-Volume Migration of Elastic Seismic Data with Low Spatial Coverage
More LessP025 Summary FRESNEL-VOLUME MIGRATION OF ELASTIC SEISMIC DATA WITH LOW SPATIAL COVERAGE S. LÜTH 1 A. GOERTZ 2 S. BUSKE 1 and R. GIESE 3 1 Institut für Geologische Wissenschaften Fachrichtung Geophysik Freie Universität Berlin Malteserstraße 74-100 12249 Berlin Germany 2 Paulsson Brea USA 3 GeoForschungsZentrum Potsdam Germany A method for imaging multi-component seismic data using vector Kirchhoff migration with a restriction to the Fresnel volume of the reflection wave path is proposed. This method is particularly applicable for seismic data with restricted aperture as e.g. along tunnels or VSP. We use the polarization direction of multi-component data in order
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Self Potential Measurements During Hydraulic Fracturing of Bunter Sandstones
Authors M. Grinat, J. Sauer and W. SüdekumP026 SELF POTENTIAL MEASUREMENTS DURING HYDRAULIC FRACTURING OF BUNTER SANDSTONES INTRODUCTION 1 Self potentials (SP) at the earth’s surface are not only caused by electrochemical reactions but also by electrokinetic phenomena in the subsurface. The electrokinetic or streaming potentials originate from the movement of fluids in porous rocks which is due to a pressure gradient. Laboratory measurements show a clear correlation between the injection pressure and the streaming potential (e.g. MOORE et al. 2003). The electrokinetic potentials can be used to study the movement of water in near-surface layers (REVIL et al. 2002). Moreover within the last years several publications
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Electromagnetic Data Inversion Using Genetic Algorithm
Authors N. Amini and M.K. HafiziP027 ELECTROMAGNETIC DATA INVERSION USING GENETIC ALGORITHM Abstract 1 Genetic algorithm is an efficient tool for optimization and its applications is growing in engineering and science. In this paper we applied it for electromagnetic data inversion. Our inputs are magnetic components of the measurement and output is current density cross section. Introduction Current density sections are known concepts in EM data interpretation and their problems are usually solved by linear filter theory (koefoed Ghosh Polman 1972 Mallick and Verma 1978). These methods try to calculate current density cross sections that are responsible for observed anomaly at the surface. These sections
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New Filter for Calculation of Current Density Pseudosections from VLF Dip Angle Data
Authors N. Amini and M.K. HafiziP028 NEW FILTER FOR CALCULATION OF CURRENT DENSITY PSEUDOSECTIONS FROM VLF DIP ANGLE DATA Abstract 1 VLF is one of popular electromagnetic prospecting techniques. In spite of easy data acquisition it’s data interpretation is complicated and there is not a certain method for it. Current density pseudosections that can be calculated by raw data filtering are good tools for preliminary interpretation. In this research we proposed a new approach for obtaining them. Introduction Current density pseudosections are known in EM data interpretation and they are usually constructed by linear filters theory (Karous & Hjelt 1983). These filters can calculate current
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