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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
1 - 100 of 132 results
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Correction of Buildings, Basements and Bridge Influences in an Urban Microgravimetry Survey
Authors P. Chasseriau, P. Radogna, P. Logean and R. OlivierA001 CORRECTION OF BUILDINGS BASEMENTS AND BRIDGE INFLUENCES IN AN URBAN MICROGRAVIMETRY SURVEY 1 Summary A microgravity survey was carried out in summer 2002 and 2003 for modelling the molassic bedrock in Lausanne a high-urbanized city in Switzerland. The project of a new underground determined the availability of continuously updated mechanical loggings data that permitted us to check our models and to find out a routine procedure. We could evaluate influence of basements and large buildings. Firstly we had to ameliorate the digital elevation model (DEM) to have precise near topographical corrections and exact interfaces between basements and topography. Roads
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The Use of Microgravity for the Detection and Characterization of Sinkholes and Historic Extraction Features in the Chalk
Authors P. Styles, S. Toon, E. Thomas and M. SkittrallA002 THE USE OF MICROGRAVITY FOR THE DETECTION AND CHARACTERIZATION OF SINKHOLES AND HISTORIC EXTRACTION FEATURES IN THE CHALK 1 P. STYLES S. TOON E. THOMAS and M. SKITTRALL 1 Applied and Environmental Geophysics Research Group Keele University Keele Staffs. ST5 5BG UK 2 Geotechnology 3 Mouchel Parkman GB Ltd Chalk has been extracted extensively in the United Kingdom for more than 4 000 years with excavations for flints at Grimes Graves near Thetford in Norfolk probably being the earliest instance. From as early as Roman and Saxon times the flint contained within the chalk was initially quarried and mined
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Multichannel Spectral Induced Polarization (Sip) – Application to Geotechnics and Construction Materials
Authors E. Niederleithinger, S. Kruschwitz, M. Behrens and A. BrinkA003 MULTICHANNEL SPECTRAL INDUCED POLARIZATION (SIP) - APPLICATION TO GEOTECHNICS AND CONSTRUCTION MATERIALS Introduction 1 Geoelectrical methods are applied in many fields of civil engineering. They are used for building ground inspection hydrogeological investigations or moisture determination in building materials. Both instrumentation and interpretation software are commercially available and relatively simple to use. But the measured parameter (electrical resistivity) is often ambiguous. For example there is no unique correlation between resistivity and moisture. Many other parameters in particular salt content have great influence on the measurements. So other methods (geophysical or not) have to be used to calibrate the results.
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Microseismic Monitoring of Abandoned Salt Mines beneath Northwich, Cheshire, UK
More LessA004 MICROSEISMIC MONITORING OF ABANDONED SALT MINES BENEATH NORTHWICH CHESHIRE UK Introduction 1 S.M. TOON AND P.STYLES Applied and Environmental Geophysics Research Group Keele University School of Earth Sciences & Geography Keele Staffordshire ST5 5BG United Kingdom The Cheshire Salt Field has been the site of salt mining and wild brine pumping from Roman times for industry on Merseyside and Cheshire. Whilst mining under Northwich ended in 1928 there has been a history of continuing subsidence. Salt and brine extraction formed the basis of mid-Cheshire's chemical industry the primary economic force for the area up to the 1960's. Since then
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Borehole-to-Surface ERT Inversion
Authors P. Tsourlos, R.D. Ogilvy and C. PapazachosA005 BOREHOLE-TO-SURFACE ERT INVERSION Introduction 1 Increasing use is being made of cross-hole ERT to scan between two or more boreholes (Daily and Owen 1991; Daily and Ramirez 2000). However cross-hole tomography cannot be used successfully if the boreholes are too widely spaced. In such cases combined use of surface and single-hole electrodes (Bevc and Morrison 1991) or even single-hole ERT measurements can be considered (Tsourlos et al. 2003). Although the cross-hole ERT case has been studied extensively only limited information about the borehole-to-surface ERT measuring mode exists in the literature. In this work we examine the case of inverting
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Interpretation Enhancement by Combining SIP and NMR
Authors M. Müller and U. YaramanciA006 INTERPRETATION ENHANCEMENT BY COMBINING SIP AND NMR Introduction 1 The nuclear magnetic resonance (NMR) technique is mainly known in geophysics for well logging and laboratory measurements of cores. Therefore most publications in geophysics deal with the NMR properties of hard rocks. NMR is observed with nuclei of certain atoms which are immersed in a static magnetic field and exposed to a secondary oscillating magnetic field. The advantage of NMR is based on its direct sensitivity to hydrogen (water) protons ( 1 H). Furthermore structural parameters as porosity pore size distribution or permeability of porous media can be determined by
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Applicability of the Linear Model to Interpretation of Magnetic Resonance Soundings
By A. LegchenkoA007 APPLICABILITY OF THE LINEAR MODEL TO INTERPRETATION OF MAGNETIC RESONANCE SOUNDINGS Summary 1 Interpretation of Magnetic Resonance Soundings (MRS) is based on a correct modeling of the magnetic resonance response from groundwater. It is known from nuclear physics that for small flip angles (also called tilt angle) of the nuclear magnetization the spin system is linear and for larger flip angles it is not. Within investigated by MRS volume an alternating magnetic field produced by the surface loop varies by a few orders of magnitude thus producing a large variety of the flip angles of the nuclear magnetization of
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Laterally Constrained 1D-Inversion of 3D TEM Data
Authors E. Auken, A.V. Christiansen, L. Jacobsen and K.I. SørensenA008 LATERALLY CONSTRAINED 1D-INVERSION OF 3D TEM DATA Summary 1 In this presentation we show that the interpretation of spatial densely sampled TEM data over 2D earth structures is greatly enhanced by inverting the data using the 1D-LCI algorithm (Laterally Constrained Inversion). In the 1D-LCI algorithm neighboring models are constrained laterally on layer resistivities and interfaces. Introduction E. AUKEN A. V. CHRISTIANSEN L. JACOBSEN AND K. I. SØRENSEN The HydroGeophysics Group Department of Earth Sciences University of Aarhus Denmark Finlandsgade 8 8200 Århus N Transient EM (TEM) is commonly used in hydrogeophysical investigations as a fast and relatively cheap method
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Characterization of Ashes in a Landfill with Magnetic and Electrical Methods
Authors J.C. Gourry, V. Laperche and A. BitriA009 CHARACTERIZATION OF ASHES IN A LANDFILL WITH MAGNETIC AND ELECTRICAL METHODS Abstract 1 Thermal power plants waste ashes containing heavy metals have been stored and covered by domestic wastes in a landfill near Trieste (Italy). The objective of this study is to locate these ashes polluting the environment with geophysical methods. SASW 3D electrical resistivity tomography (ERT) and vertical magnetic gradient data were collected on a small test area where ashes were suspected. Niton X-fluorescence data were also collected at surface of the landfill to measure metallic compounds concentrations. SASW profile provided a high resolution S-wave velocity vertical section
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Ground-Truthing Airborne EM – Hydrochemical Characterization of a Coal Mine Plume
Authors D. Beamish, B.A. Klinck and J. TrickA010 GROUND-TRUTHING AIRBORNE EM – HYDROCHEMICAL CHARACTERIZATION OF A COAL MINE PLUME 1 Abstract A trial airborne EM (AEM) survey was carried out across a 13 x 9 km area of the northern Nottinghamshire (UK) coalfield. One of the objectives was to examine the influence of collieries situated above the Triassic Sherwood Sandstone aquifer. The conductivity models obtained from the AEM survey revealed extensive zones of enhanced subsurface conductivity in the vicinity of all the collieries in the survey area. The purpose of the present study is to provide information regarding subsequent investigations (ground geophysics and borehole) to confirm the
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Charactrization of the Landfill Using Ves Data Inversion
Authors M. Mirzaei and F. GhadimiA011 CHARACTRIZATION OF THE LANDFILL USING VES DATA INVERSION 1 INTRODUCTION The pollution of aquifers by landfills can contaminate valuable and scarce water resources in most overcrowded communities. The pollution in freshwater can be due to flow of leachate into the aquifers. Pollution investigations can involve determining hydro-geological lithological and structural characteristics at a site; assessment of relations and connections between the land surface and groundwater; detection of the presence of pollutants in the vadose and groundwater zones; and estimation of pollutant concentrations and patterns of movement. Surface geo-electrical methods have been used to image groundwater contamination for a number
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Investigation of a Former Quarry and Landfill Site Using Electrical Resistivity Tomography
Authors J.E. Chambers, P.I. Meldrum, O. Kuras, R.D. Ogilvy and J. HollandsA012 INVESTIGATION OF A FORMER QUARRY AND LANDFILL SITE USING ELECTRICAL RESISTIVITY TOMOGRAPHY 1 J. E. CHAMBERS 1 P. I. MELDRUM 1 O. KURAS 1 R. D. OGILVY 1 AND J. HOLLANDS 2 1 British Geological Survey Keyworth Nottingham NG12 5GG UK 2 North Lanarkshire Council SUMMARY A study of 2D and 3D electrical resistivity tomography (ERT) surveys of a landfill in a former dolerite quarry situated in the Midland Valley of Scotland is described. The main objective of the ERT surveys was to characterise the landfill geometry in terms of lateral extent and depth. In addition it was anticipated
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Groundwater Research Within the Estancia Basin, New Mexico
Authors J. Dimick, V. Mitchell, D. Klepacki and M. WennogleA013 GROUNDWATER RESEARCH WITHIN THE ESTANCIA BASIN NEW MEXICO Introduction and Background 1 The Colorado School of Mines Geophysics Summer Field Camp (GPGN 486) is a required course for the Mines undergraduates; however this unique opportunity to apply course theory with practical academic investigation has also attracted graduate students and students visiting from other schools for more than 50 years. Traditionally the course has been taught in Colorado and consists of a week of geologic mapping two weeks of geophysical data acquisition and a week of data processing with interpreting before a final presentation. In the fall of 2002 the
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Relationship Between Biodegradation and Bulk Electrical Conductivity
Authors E. Atekwana, E.A. Atekwana, F.D. Legall, R.V. Krishnamurthy and W.A. SauckA014 RELATIONSHIP BETWEEN BIODEGRADATION AND BULK ELECTRICAL CONDUCTIVITY Abstract Groundwater chemistry data were used to assess the relationship between high bulk conductivity zones and biodegradation of hydrocarbon. Biodegradation was verified using terminal electron acceptors (nitrate sulfate and iron) dissolved inorganic carbon (DIC) and the isotope ratio of DIC (delta 13 CDIC). The bulk conductivity was measured using in situ vertical resistivity probes. The results show that peak values in the bulk conductivity occurred in zones in the aquifer where total petroleum hydrocarbon were high and nitrate sulfate and iron reduction were occurring. Also in the zones where bulk conductivity was
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Constrained Inversion of Helicopter AEM Data for Managing Irrigation Salinity
More LessA015 CONSTRAINED INVERSION OF HELICOPTER AEM DATA FOR MANAGING IRRIGATION SALINITY ANDY GREEN 1 ROSS BRODIE 2 TIM MUNDAY 3 Abstract 1 The RESOLVE frequency domain HEM system has been used to map the distribution of near-surface clay-rich sediments in and around the Riverland irrigation districts of South Australia. The data were recalibrated with measurements from down-hole induction logs and then inverted using a 1-D layeredearth model. The inversion was constrained with as much geological and hydrogeological information as possible. The resulting detailed map of the distribution of the Blanchetown Clay is being used to model the recharge behavior of
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Towards Three and Four Dimensional Data Collection for Electrical Resistivity Data
Authors D.J. La Brecque, R. Sharpe and M. StubbenA016 TOWARDS THREE AND FOUR DIMENSIONAL DATA COLLECTION FOR ELECTRICAL RESISTIVITY DATA Summary 1 Advances in hardware and software have made the collection of fully three-dimensional and four dimensional resistivity data not only possible but practical. To fully utilize these new capabilities requires new approaches to collecting data. We compare more traditional one- and two- dimensional data collection strategies with fully three-dimensional strategies that include array patterns such as horizontal subsurface dipoles not possible in older two-dimensional schemes. Finding optimal arrays requires tradeoffs in resolution acquisition time and signal levels. A new statistical based approach is shown that can be
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Using Resistivity Measurements for Dam Safety Evaluation at Enemossen Tailings Dam
Authors P. Sjödahl, T. Dahlin and S. JohanssonA017 USING RESISTIVITY MEASUREMENTS FOR DAM SAFETY EVALUATION AT ENEMOSSEN TAILINGS DAM 1 SJÖDAHL P.* DAHLIN T.* JOHANSSON S.** * Dept. of Engineering Geology Lund University Box 118 221 00 Lund Sweden [email protected] [email protected] ** HydroResearch Sam Johansson AB St. Askens väg 6 183 65 Täby Sweden [email protected] INTRODUCTION Internal erosion is one of the major reasons for embankment dam failures. Resistivity measurements may have the possibility of detecting internal erosion processes and anomalous seepage at an early stage before the safety of the dam is at stake. The technique is essentially non-destructive which is particularly important when working with
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Quantitative Inspection of Sewer Systems Using Geophysical Methods
Authors D. Orlowsky, B. Lehmann, A. Redmann and T. KabbeA018 QUANTITATIVE INSPECTION OF SEWER SYSTEMS USING GEOPHYSICAL METHODS Abstract 1 To investigate the conditions of accessible underground sewer systems the geophysical methods seismics ground penetration radar (GPR) methods from borehole geophysics ultrasonic and impact-echo measurements as well as gravity geoelectrics electromagnetics and thermography had been applied in a 40 m long artificial underground test track in Gelsenkirchen (Germany). The test sewer track consists of different concrete pipes with diameters of 2.2 m and concrete thickness’ between 20 and 42 cm which are usually used in Germany. The goals of the test measurements were to find techniques which get more
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Non-Invasive Characterisation of Road Subgrade with Towed-Array Capacitive Resistivity Imaging
Authors O. Kuras, P.I. Meldrum, D. Beamish and R.D. OgilvyA019 NON-INVASIVE CHARACTERISATION OF ROAD SUBGRADE WITH TOWED-ARRAY CAPACITIVE RESISTIVITY IMAGING Summary 1 A towed-array Capacitive Resistivity Imaging (CRI) system has been used in a controlled experiment to acquire multi-channel high-resolution ERT data on an asphalt road. Results from a CRI survey on a purpose-built trial road are discussed and compared to corresponding GPR profile data. It is demonstrated that CRI is particularly effective for the assessment of road subgrade condition. The technique is found to be sensitive to variations in moisture content and porosity in the subgrade layer which can be used to distinguish areas of structural weakness in
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Geophysical Investigation of Slow Active Faults in the Provence Area (France)
Authors D. Jongmans, F. Nguyen, S. Garambois, D. Chardon, O. Bellier and D. HermitteA020 GEOPHYSICAL INVESTIGATION OF SLOW ACTIVE FAULTS IN THE PROVENCE AREA (FRANCE) Introduction 1 In regions of low to moderate seismic activity such as Western Europe seismic hazard assessment often requires careful studies of active faults that have very long recurrence intervals and tenuous morphological expressions due to substantial erosion rates vegetation coverage and human activity (Peulvast et al. 1999). Moreover most of Western Europe is characterized by a relatively high seismic risk due to the concentration of human and material properties presenting high-vulnerability. Consequently detecting tectonic structures that may lead to destructive earthquakes (i.e. Basel 1356; Verviers 1692; Lambesc
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Cross-Borehole Resistivity Tomography below Foundations in Covered Karst
Authors J. Deceuster, J. Delgranche and O. KaufmannA021 CROSS-BOREHOLE RESISTIVITY TOMOGRAPHY BELOW FOUNDATIONS IN COVERED KARST AUTHORS Abstract 1 This paper presents a case study conducted below building foundations in a karstic area at Tournai (Belgium). Geophysical investigations were carried out to map the complex geometry of the subsurface. Twenty-three cross-borehole resistivity panels with multiple arrays were performed on the site. Data were inverted with Res2DInv ® software. Tomographies give a good overview of the competent bedrock geometry and also allow to delineating covered weathered limestone. Introduction The investigated building is situated at Tournai in the south-west of Belgium. Several collapses from 2 to 3 meters in
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High Resolution Seismic Experiment within the Low-Noise Underground Laboratory (LSBB) of Rustrel (Province)
Authors G. Sénéchal, D. Rousset, E. Gloaguen and T. LebourgA022 High resolution seismic experiment within the low-noise underground laboratory (LSBB) of Rustrel (Provence). Abstract (1) (1) (2) (3) GUY SÉNÉCHAL DOMINIQUE ROUSSET ERWAN GLOAGUEN AND THOMAS LEBOURG (1) FRE 2639 – Imagerie Géophysique Pau – IPRA Université de Pau et des Pays de l'Adour - 64000 Pau – France (2) Dép. Des Génies Civil Géologiques et des Mines – École Polytechnique de Montréal - Montréal C.P.6079 – Canada 1 (3) UMR 6526 - Géosciences Azur – Sophia Antipolis 06560 Valbonne – France Several high resolution seismic experiments have been performed along underground galleries located 200 meters below the surface.
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Advances in the Interpretation of Geophysical Borehole Logs
Authors M.G.G. de Jong, S.D. Nio, D.T. Biewinga and D.G. SmithA023 ADVANCES IN THE INTERPRETATION OF GEOPHYSICAL BOREHOLE LOGS Summary 1 Modern software packages greatly facilitate the analysis and interpretation of geophysical borehole logs. Standard applications in hydrogeology and petroleum geology such as the evaluation of lithology and reservoir fluids are nowadays carried out routinely with such software. A disadvantage of most packages is that they are developed for the experienced geophysicist. Software tailored to the needs of geologists and hydrologists is now also available. Using flexible scaling options histograms and advanced multiple log display functions the non-petrophysicist can quickly evaluate lithological parameters and the nature of the fluids in
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Random Gridding Decomposition (RGD) in Seismic Tomography
By B. AbbadA024 RANDOM GRIDDING DECOMPOSITION (RGD) IN SEISMIC TOMOGRAPHY Abstract 1 The purpose of this work is to invert crosswell first arrival data on a high resolution velocity grid called the fundamental grid obtained by running several tomographic inversions on grids of smaller size generated randomly. Later the inversion results of these grids are scaled by the ray density and the pixel area to produce a final velocity image with a better resolution. The method has proven a significant gain in computing time for the inversion and has given superior results than those provided using simple grids of similar size especially
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Integrated GPR and Geo-Resistivity Study of Shallow Stratigraphy in Sandy Coastal Environments
Authors M. Pipan, E. Forte, M. Sugan, G. Dal Moro and P. GabrielliA025 INTEGRATED GPR AND RESISTIVITY STUDY OF SHALLOW STRATIGRAPHY IN SANDY COASTAL ENVIRONMENTS Abstract 1 We performed an integrated Multi-Fold GPR and resistivity survey in a coastal area in the northern part of Italy (Adriatic coast) to reconstruct 3D stratigraphy to localize vadose zone and water table and to identify possible man-made structures and excavations. The spatial sampling was sufficiently dense to perform 3-D interpretation of radar data and 2.5-D reconstruction of iso-resistivity surfaces across the grid. Processing of GPR Single and Multi Fold data focused on true amplitude signal recovery in order to preserve information related to electromagnetic impedance
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Soil Moisture Dynamics with Time Lapse GPR
Authors J. Schmalholz, A. Kemna, M. Müller, H. Stoffegen and U. YaramanciA026 SOIL MOISTURE DYNAMICS WITH TIME LAPSE GPR J. SCHMALHOLZ 1 A. KEMNA 2 M. MÜLLER 1 H. STOFFEGEN 3 AND U. YARAMANCI 1 Introduction 1 Tracing the water content in the uppermost soil is of great interest for a variety of different scientific disciplines. Since many processes are linked to the volumetric water content and its dynamics the scale of interest ranges from kilometres to submetres. With the availability of shielded high frequency ground penetrating radar (GPR) antennas a non- respectively minimally invasive geophysical tool valuable information concerning the water content can be obtained with a spatial resolution in
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Monitoring of Water Infiltration Using GPR Data
Authors P. de Beukelaar, S. Mazouz, M. Meinster, A. Saintenoy and P. TucholkaA027 Monitoring of water infiltration using GPR data Summary A Ground Penetrating Radar survey was carried out for water infiltration monitoring and mapping of shallow subsurface conditions. A first measurement allowed high resolution mapping of subsurface conditions and assessment in variations of the GPR reflection response for saline water infiltration in the upper few metres of unsaturated soil. In total three sites with representative lithologies of the Paris Basin were investigated to compare hydrologic behaviour in different types of soil. This paper shows results from both synthetic modelling as well as from measurements carried out over sands nearby Rambouillet. Further
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Fracture Characterisation Using the NA Inversion Algorithm on Synthetic GPR Signals
Authors C. Gregoire, M. Jeannin, M. Wathelet, S. Garambois and D. JongmansA028 FRACTURE CHARACTERISATION USING THE NA INVERSION ALGORITHM ON SYNTHETIC GPR SIGNALS Abstract 1 The geometry and properties of discontinuities are very important in the rock mass stability assessment. The GPR method which is able to yield information about the internal structure of resistive rocks was applied in extreme conditions to image sub-vertical cliffs. The profile interpretation allowed to locate several discontinuities whose characterisation required an analysis based on the frequency content of the radar reflection. The possibilities and the limitations of the reflectivity inversion were previously tested with a grid search within the parameter space. In this paper we
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GPR Measurements at the Site of a German Medieval Imperial Palatinate
More LessA029 GPR MEASUREMENTS AT THE SITE OF A GERMAN MEDIEVAL IMPERIAL PALATINATE SUMMARY 1 Measurements with the ground penetrating radar (GPR) are very useful in exploring archaeological sites. The main features are high resolution and fast data acquisition. In practice there are some problems which have to be overcome: low material contrast of the archaeological objects to the surrounding layers and strong reflective layers near the surface. Several processing steps are presented and discussed which were chosen to improve the signal to noise ratio. The results could be tested because parts of the area had been excavated several years ago
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Fast Imaging of a Romano-Celtic Temple with a Decimetric Resolution – 1 Ha in 2 Hours?
More LessA030 FAST IMAGING OF A ROMANO-CELTIC TEMPLE WITH A DECIMETRIC RESOLUTION – 1 HA IN 2 HOURS ? Abstract 1 Archaeological exploration of buried targets with non destructive techniques is becoming more and more important but has to face a specific problem of spatial resolution: most of our heritage is buried in the first meter below the ground surface and in order to obtain a good resolution of images we need a ground resolution of the order of several decimetres. Exploration of areas of more than several hectares with this resolution need lot of time and money and is not
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Rapid and Precise Archaeogeophysical Survey Using a Multi-Sensor Platform (MSP)
Authors I.A. Hill and N. LinfordA031 RAPID AND PRECISE ARCHAEOGEOPHYSICAL SURVEY USING A MULTI-SENSOR PLATFORM (MSP) Abstract 1 I. A. HILL 1 AND N.LINFORD 2 1 Department of Geology University of Leicester Leicester LE1 7RH UK. Email: [email protected] 2 English Heritage Centre for Archaeology Fort Cumberland Fort Cumberland Road Eastney Portsmouth PO4 9LD UK Email: [email protected] Archaeogeophysical surveys are established as vital tools for archaeological investigations. The target physical property contrasts are often small and the anomalies subtle. Magnetic surveys are perhaps the epitome of these surveys where the anomalies sought are only a few nannoteslas in amplitude and of the order of a metre
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MULTISENSOR - A Mobile Geophysical Multi-Sensor System for Archaeological Prospecting
Authors S. Woelz, E. Erkul, W. Rabbel and H. StümpelA032 MULTISENSOR – A MOBILE GEOPHYSICAL MULTI-SENSOR SYSTEM FOR ARCHAEOLOGICAL PROSPECTING Summary 1 We show first results of a new highly mobile multi-sensor system for archaeological prospecting. It has been developed for the geophysical investigation of large kilometer-scale antique settlement areas with high resolution in an economic way. The system comprises a four-wheel drive tractor and a trailer carrying magnetic electro-magnetic and ground penetrating radar sensors. Positioning is performed online using differential GPS. Introduction: New demands for archaeological prospecting E. ERKUL W. RABBEL H. STÜMPEL AND S. WOELZ Institute of Geosciences Geophysics Kiel University Otto-Hahn-Platz 1 24118 Kiel Germany In
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Integrated Inversion of CVES and TEM Data Using Lateral Constraints
Authors A.V. Christiansen, N. Foged, E. Auken and K.I. SørensenA033 INTEGRATED INVERSION OF CVES AND TEM DATA USING LATERAL CONSTRAINTS Summary 1 We present a mutually and laterally constrained inversion between transient electromagnetic (TEM) and geoelectric (DC) data sets. Although both methods measure in some sense the electrical resistivity or conductivity of the subsurface they sample different volumes and have different sensitivities. The different sampling volumes and different sensitivities are exploited by the mutually and laterally constrained inversion algorithm combining the coinciding profile data sets. The output model incorporates the information from both profile data sets to obtain the optimum layered 1D models fitting both data types. All data
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Joint Inversion of TEM and DC Soundings
Authors P.O. Barsukov, E.B. Fainberg and E.O. KhabenskyA034 JOINT INVERSION OF TEM AND DC SOUNDINGS Abstract 1 P.O. BARSUKOV E.B. FAINBERG AND E.O. KHABENSKY Institute of Physics of the Earth RAS Troitsk branch 142190 Troitsk PO Box 30 Moscow region Russia It is well known that DC (direct current) soundings are very sensitive to resistive layers and structures imbedded in section and insensitive to conductive layers. On the contrary TEM (transient electromagnetic method) is sensitive to conductive layers and insensitive to resistive ones. The real paper describes the way of joint inversion both DC and TEM data in 1D class of layered sections providing construction of a
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Interpretation of a Hydrogeophysical Survey – Data from the High-Resolution SkyTEM System
Authors K.I. Sørensen, B. Sørensen, A.V. Christiansen and E. AukenA035 INTERPRETATION OF A HYDROGEOPHYSICAL SURVEY – DATA FROM THE HIGH- RESOLUTION SKYTEM SYSTEM Abstract 1 During the last decade approximately 50 000 ground-based TEM soundings have been carried out in Denmark for groundwater investigations. This number will increase in the future and therefore we have developed a new time-domain electromagnetic (TEM) helicopter system SkyTEM. In the development and design of the SkyTEM system it has been an unchangeable demand that the data quality of the SkyTEM system should be the same or better than the data quality of ground-based systems e.g. the Protem 47 system (40 x 40 m
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Constrained Inversion of Helicopterborne EM Data
By H. ThunehedA036 CONSTRAINED INVERSION OF HELICOPTERBORNE EM DATA Summary 1 Helicopterborne EM data from two surveys in Sweden have been inverted into two-layered models. The surveys were carried out in areas of resistive crystalline rock. The leveling of the data was aided by geophysical measurements on the ground. Ground truth information was also used as constraints during inversion. The data was treated in a regular grid over the survey area and a two-layer model for each grid node was produced. These models were stitched together to give a continuos description of the bedrock resistivity and the soil cover resistivity and thickness
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Empirical Inversion of HEM Data for Sea Ice Thickness Mapping
Authors A. Pfaffling, C. Haas and J.E. ReidA037 EMPIRICAL INVERSION OF HEM DATA FOR SEA ICE THICKNESS MAPPING Summary 1 Since 2001 the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven (AWI) has operated a purpose built unique HEM system to map sea ice thickness in the Arctic and Antarctic. To determine the sea ice thickness from the measured EM field we use an empirical curve fitting approach. The master curve is tuned for every flight leg using measurements over open water between the ice floes in leads or polynyas. The level ice thickness which is a key value for sea ice science and climate
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Magneto-Electric Mapping of 3D Electrical Conductivity Distributions – System Design and Resolution Analysis
Authors A. Verweerd, A. Tillmann, E. Zimmermann, A. Kemna and H. VereeckenA038 MAGNETO-ELECTRIC MAPPING OF 3D ELECTRICAL CONDUCTIVITY DISTRIBUTIONS – SYSTEM DESIGN AND RESOLUTION ANALYSIS Abstract 1 In order to map the electrical conductivity distribution in cylindrical soil columns a combined measurement of the electric potential and the three magnetic field components due to a low frequency current injection is proposed. The magnetic field is measured by means of a vertical moving scanning torus with 24 sensor modules capable of measuring in a range of 200 nT with a resolution of 50 pT without the use of extensive magnetic shielding. Numerical simulations prove the additional value of the magnetic dataset when
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Moisture Dynamics in Urban Soils with High Resolution Geoelectrics
Authors M. Müller, O. Mohnke, J. Schmalholz and U. YaramanciB001 MOISTURE DYNAMICS IN URBAN SOILS WITH HIGH RESOLUTION GEOELECTRICS Introduction 1 Urban soils are subject to strong variations of environmental conditions like in water flow solute transport or heat budget. The research project INTERURBAN has been formed to investigate the dynamics of water and solutes at urban locations with particular attention to the spatial heterogeneity the organic soil substance and soil-biological transformation processes in the unsaturated zone. The objectives of INTERURBAN define also the tasks for geophysics: The development of a noninvasive conception to map water distribution water dynamics and important physical parameters on small scales. Approaches to adopt
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Streaming Potentials Associated with Well-Pumping – Analogical and in Situ Results
By F.A. GassB002 STREAMING POTENTIALS ASSOCIATED WITH WELL-PUMPING – ANALOGICAL AND IN SITU RESULTS Summary 1 Water flowing in a porous media causes natural electrical currents called streaming potentials. Thus during pumping the inflow of water to the well causes a positive potential anomaly above the well. Analogical experiments in a tank during well-pumping show that the piezometric surface acts as a dipolar electrical source. Furthermore measurements of the streaming potentials before during and after pumping show that they are linearly dependent of the variation of the water level thus allowing calculation of the coupling coefficient around the well. This opens some
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The Effect of Changing the Salinity of the Groundwater on SIP of Sandstones
Authors A. Weller, J. Scott, N. Schleifer and R. BarkerB003 THE EFFECT OF CHANGING THE SALINITY OF THE GROUNDWATER ON SIP OF SANDSTONES SUMMARY 1 Previous work between the University of Birmingham and Technical University Clausthal examined the basic shape of the complex conductivity spectra of sandstones saturated with a synthetic groundwater solution and compared the two different laboratory measurement procedures. It is known that the Spectral Induced Polarisation (SIP) is also dependent upon the pore fluid so we examined the effect of two different salinity groundwaters on the SIP response. The changes caused by decreasing the salinity of the groundwater varied widely for different sandstones with both increasing
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Hydrogeophysical Study at an Olive Farm, S. Italy
Authors R. Meissner, S.A. al Hagrey and A. IsmaeilB004 HYDROGEOPHYSICAL STUDY AT AN OLIVE FARM S. ITALY Summary 1 We present results of hydrogeophysical experiments at an olive farm with calcareous soils at Canosa S. Italy. Geoelectric subsurface models down to 8 m depth display the main waterfed layer for trees. In infiltration experiments hydroelectrical monitoring images the water penetration into soils in 2D and 3D. From diverse petrophysical (insitu and lab) analyses on soil samples we could establish a reliable empirical resistivity-water content relationship similar to that of Archie. This was applied to derive pore water distributions from electric models. We could find that diverse biological und
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High-Resolution Echo-Sounding and Estimation of Sediment Properties Using Nonlinear Acoustics
Authors J. Wunderlich and G. WendtB005 HIGH-RESOLUTION ECHO-SOUNDING AND ESTIMATION OF SEDIMENT PROPERTIES USING NONLINEAR ACOUSTICS Abstract 1 There are a lot of advantages using nonlinear echo sounders compared to linear ones in particular in shallow water areas. An important problem in sediment acoustics is to determine the thickness of sediment layers. If the sound velocity is known the thickness can be calculated from the travel times. Nonlinear acoustics combined with principles of refraction seismic allow to estimate the sound velocity of selected sediment layers. Nonlinear acoustics has also advantages while obtaining frequency dependent sediment properties like attenuation coefficients. Nonlinear Acoustics JENS WUNDERLICH and GERT
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Two Acoustic Methods for Classification of Near-Surface Sediments
Authors C.S. Mesdag, P.T.J. Kok, R. Romijn, G. Blacquiere, M. Snellen and D.G. SimonsB006 TWO ACOUSTIC METHODS FOR CLASSIFICATION OF NEAR-SURFACE SEDIMENTS Abstract 1 C. S. MESDAG 1 P. KOK 1 R. ROMIJN 2 G. BLACQUIERE 2 M. SNELLEN 3 and D. G. SIMONS 3 4 1 TNO NITG Netherlands Institute for Applied Geoscience Princetonlaan 6 3508 TA Utrecht The Netherlands The Dutch Ministry of Transport Public Works and Water Management North Sea Directorate (RWS-DNZ) is investigating the amount of extractable coarse sand within the upper 100 m sediment in the Dutch part of the North Sea. Coarse sand is needed for the concrete and mortar industry. The method used to date is
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Shallow Gas in the Baltic Sea from a VHR 2.5-D Seismic View
By C. MüllerB007 SHALLOW GAS IN THE BALTIC SEA FROM A VHR 2.5-D SEISMIC VIEW 1 C. MÜLLER Inst. for Geosciences Dep. of Geophysics Kiel-University Otto-Hahn-Platz 1 24118 Kiel Germany Summary This case history demonstrates the feasibility of acquiring processing and interpreting a shallow marine very high resolution 2.5-D seismic cube. A simple processing sequence (“brute stack cube”) based on only nominal knowledge about acquisition geometry revealed complex small scale geological strucutres on time slices and by interpretation. An extensive shallow gas field hosted in Holocene unconsolidated sediments is mapped Site location and acquisition concept In the Northern German Basin salt tectonics
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Integrated Repetitive Multibeam Bathymetry and Geophysical Surveys of an Offshore Disposal Site
Authors D.R. Parrott, M.B. Parsons, M.Z. Li, V. Kostylev, J.E. Hughes Clarke, A. Duxfield and K.-L. TayB008 INTEGRATED REPETITIVE MULTIBEAM BATHYMETRY AND GEOPHYSICAL SURVEYS OF AN OFFSHORE DISPOSAL SITE Abstract 1 D.R. PARROTT 1 M.B. PARSONS 1 M.Z. LI 1 V. KOSTYLEV 1 J.E. HUGHES CLARKE 2 A. DUXFIELD 2 K-L. TAY 3 The Black Point Ocean Disposal Site has received material dredged from shipping channels and near wharves in Saint John Harbour New Brunswick Canada for over 50 years. The disposal site is located at an exposed position in the harbour approaches where it is affected by strong currents 8 metre high tides and waves from winter storms (Fig. 1). Disposal activities had resulted in
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Applying Seismic Traveltime Tomography in the Exploration of the Foundations of a Byzantine Church
Authors L. Polymenakos and S. PapamarinopoulosB009 APPLYING SEISMIC TRAVELTIME TOMOGRAPHY IN THE EXPLORATION OF THE FOUNDATIONS OF A BYZANTINE CHURCH Abstract 1 This paper discusses the application of seismic traveltime tomography as employed to the exploration of the foundation structure and ground material of a Byzantine church. Byzantine churches are monuments of high historical cultural and artistic value. Moreover they are often important engineering and architectural constructions. Their preservation presents special concerns since it has to cope with specific building and foundation conditions. The investigation of the foundations of these buildings is of great interest since it can provide important information both on subsurface conditions
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High-Resolution Electrical Resistivity Imaging at a Former Industrial Furnace Site, PA, USA
Authors B. Kulessa, S. Haney, P. McCarthy and B. ChiarulliB010 HIGH-RESOLUTION ELECTRICAL RESISTIVITY IMAGING AT A FORMER INDUSTRIAL FURNACE SITE PA USA INTRODUCTION 1 This paper investigates the scope of high-resolution electrical resistivity imaging in resolving man-made and now buried structures at the Shade iron furnace in Co. Somerset Pennsylvania USA. Iron furnaces were widespread in Colonial America between the 17 th and 19 th centuries with 35 such sites currently being registered as historical monuments in Pennsylvania alone. Since many of these sites are aerially extensive reconstruction of former furnace operation presents a considerable challenge to traditional methods of archaeological surveying. Additional application of geophysical methods at the
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Modelling the Meagnetic Field Gradient for Archaeological Structures in Saqqara (Egypt)
Authors A. El-Bassiony and A. WellerB011 MODELLING THE MEAGNETIC FIELD GRADIENT FOR ARCHAEOLOGICAL STRUCTURES IN SAQQARA (EGYPT) SUMMARY 1 The magnetic prospection for archaeological structures in the northern cemetery of Saqqara (Egypt) was carried out with a fluxgate gradiometer. The magnetic image showed an outline of a large tomb complex. An algorithm was developed to model the vertical gradient of the vertical component of the magnetic field for spherical units located at arbitrary locations and depths. We tried to simulate the archaeological structures with spheres of different sizes depths and lateral offsets using the potential equation of a sphere with a volume of an enclosing
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Radar and Electrical Resistivity Data Comparison at Izmir Agora, Turkey
Authors M. Martinaud, R. Chapoulie and M.G. DrahorB012 RADAR AND ELECTRICAL RESISTIVITY DATA COMPARISON AT IZMIR AGORA TURKEY INTRODUCTION 1 Along the seaside of the Anatolian continent at Izmir in Turkey are the vestiges of the ancient agora. As to give back to this agora its archaeological interest and some tourist attraction an important project has been set out. Within this framework an integrated prospection of the present courtyard of the agora has been performed. This study was a part of a more extensive geophysical investigation concerning the inner part and the outer part of the agora i.e. the neighbouring streets of the town. SITE DESCRIPTION The
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A New System for High Speed Spatial Mapping of Soil – The ARP© System
By M. DabasB017 A NEW SYSTEM FOR HIGH SPEED SPATIAL MAPPING OF SOIL – THE ARP© SYSTEM Abstract 1 The spatial knowledge of soil distribution is a prerequisite for new management strategies in Agriculture (Precision Agriculture: PA): the idea is to optimize the different agricultural processes (density of seeds fertilizers pesticides etc.) to the different soil zones defined as Homogeneous Zones (HZ). The spatial resolution should be of the order of 6m in both directions. For economical reasons this density cannot be obtained with traditional measurements like auger borings. Satellite- or air-based techniques suffer from the lack of penetration of the electromagnetic
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Numerical Modelling of Electroseismic Signals in Fractured, Contaminated Aquifer Systems
Authors N.J. Cassidy, G.W. Tuckwell and R.J.E. EnglandB018 NUMERICAL MODELLING OF ELECTROSEISMIC SIGNALS IN FRACTURED CONTAMINATED AQUIFER SYSTEMS Summary 1 N. J. CASSIDY 1 G. W. TUCKWELL 2 AND R. J. E. ENGLAND 1 1 School of Earth Sciences and Geography Keele University Staffordshire ST5 5BG U.K. 2 STATS Geophysical U.K. The legacy of industrial mining has left many localized aquifer systems contaminated by highly mobile pollutants that are difficult to characterise without expensive programmes of site investigation. Although geophysical techniques have been successfully applied to many of these problems electroseismic methods remain uncommon due to the complexity of the data interpretation. We present a modelling method
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Model-Based Integration of Seismic and CPT Data to Derive Soil Parameters
By R. GhoseB019 MODEL-BASED INTEGRATION OF SEISMIC AND CPT DATA TO DERIVE SOIL PARAMETERS Introduction 1 For optimum and safe design and construction practices the geotechnical and civil engineers need to have a good estimate of a number of important soil parameters. However for many valid reasons it is very difficult if not impossible to obtain reliable values for many of these key parameters. For cohesionless sandy soils it is challenging to obtain soil samples in undisturbed condition. The values obtained from the laboratory tests often do not represent the true in-situ values in soil. This contributes to increased uncertainties risks and
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Applied DC Resistivity for Tree Trunks
Authors S.A. al Hagrey, R. Meissner and A. IsmaeilB020 APPLIED DC RESISTIVITY FOR TREE TRUNKS 1 Summary We present a geoelectric technique for investigating the electric interior of cylindrical bodies and apply it to trunks of various European tree-species. Healthy trunks always show a concentric central maximum of resistivity decreasing to the outside corresponding to an increase of moisture from the inner dry heartwood to the outer wet ring of sapwood. Any anomalies are interpreted by infections or influences of branching or the direction of sunshine and wind. Introduction It is well known that various geoelectric and electromagnetic methods including ground-penetrating radar (GPR) extend the range of geophysical
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Comparison of Different Electrodes for Frequency Domain Induced Polarisation (IP) Surveys
Authors N. Schleifer and A. JungeB021 COMPARISON OF DIFFERENT ELECTRODES FOR FREQUENCY DOMAIN INDUCED POLARISATION (IP) SURVEYS SUMMARY 1 The influence of three different electrode types and combinations on Induced Polarisation (IP) surveys was investigated at three different archaeological sites using a SIP256 multichannelinstrument A measurement on dry loess soil yielded better results using stainless steel probes which is probably due to their larger contact surface and penetration depth. Including the results on a boggy soil one can say that Induced Polarisation in the frequency domain can be carried out with conventional metal probes. In general they lead to equal measurement results compared with non-polarisable
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Improving Signal-to-Noise in Electrical and EM Methods with Sensor Arrays
Authors M. Norvill and A. KepicB022 IMPROVING SIGNAL-TO-NOISE IN ELECTRICAL AND EM METHODS WITH SENSOR ARRAYS Abstract 1 The accuracy and depth of information of electrical and electromagnetic geophysical surveys is largely determined by the limits of signal detection. Many of these surveys today employ multiple sensors to collect data efficiently. However the use of multiple sensors can also be exploited to improve the signal fidelity from each sensor which translates to more accurate geological models and greater depth of investigation. In this paper we present a two step algorithm for the removal of harmonic noise and atmospheric transients the first step is the removal
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Determination of Apparent Resistivity through High-Frequency Electromagnetic Measurements
More LessB023 DETERMINATION OF APPARENT RESISTIVITY THROUGH HIGH-FREQUENCY ELECTROMAG- NETIC MEASUREMENTS Abstract 1 A technique for determining the apparent resistivity of the earth’s near-surface strata through the measurement of the mutual impedance of an array of loop antennas operating a high frequency is presented. The measuring system developed for this purpose is described. A simple method of interpreting the mutual impedance measurements to obtain a trace of the apparent resistivity of the investigated semiconducting medium is given. Finally one of the potential applications of the technique – the identification of inhomogeneities in levees – is presented. The horizontal resistivity plots obtained
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Near-Surface Electromagnetics for Imaging the Shallow Coal Seams at the Garzweiler Mine, West of Cologne
More LessB024 NEAR-SURFACE ELECTROMAGNETICS FOR IMAGING THE SHALLOW COAL SEAMS AT THE GARZWEILER MINE WEST OF COLOGNE 1 INTRODUCTION The largest single lignite or brown coal formation in Europe is found in Rhineland which covers an area of some 2 500 km 2 to the west of Cologne. RWE Rheinbraun AG is responsible for mining of lignite in Rhineland with an annual production of around 100 million metric tons which accounts for around 16% of German’s electricity supply. The "Garzweiler I" mine (Fig. 1) produces one-third of the total lignite output. The shallow stratigraphy at the "Garzweiler I" region consists of
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Shallow Shear Wave Seismic for Determining of the Average Near Surface Velocity VavS30
By U. PolomB025 SHALLOW SHEAR WAVE SEISMIC FOR DETERMINING OF THE AVERAGE NEAR SURFACE VELOCITY VAVS30 1 U. POLOM Leibniz Institute for Applied Geosciences (GGA) Stilleweg 2 D-30655 Hannover Germany Summary As part of the EU Interreg 3B research project “Oberrhein Mitte-Süd” the existing seismic microzoning study of the city of Basel will be extended to the adjacent neighbour regions in France and Germany to develop a multinational seismic risk management for this megacity area. Due to the complex geological situation of the earthquake-endangered Oberrheingraben area the common passive source seismic methods (e.g. the Nakamura method) to determine the shallow shear wave
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Shallow Imaging with Scattered Seismic Surface Waves
Authors X. Campman, C.D. Riyanti and G. HermanB026 SHALLOW IMAGING WITH SCATTERED SEISMIC SURFACE WAVES Summary XANDER CAMPMAN 1 CHRISTINA DWI RIYANTI 1 and GÉRARD HERMAN 2 1 1 Delft Institute of Applied Mathematics Delft University P.O. Box 5031 2600 GA Delft The Netherlands 2 Shell International E&P We have developed an imaging method for scattered surface waves to obtain spatial images of near-surface heterogeneities. We test our method on ultrasonic data from a laboratory test and investigate its resolution on synthetic data. The images thus obtained show that this method has potential to locate near-surface heterogeneities. Introduction It is widely recognized that surface waves provide valuable
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Offset-Variant Optimum Time Window for Near-Surface Seismic Reflection Data
By K.Y. KimB027 OFFSET-VARIANT OPTIMUM TIME WINDOW FOR NEAR-SURFACE SEISMIC REFLECTION DATA Abstract 1 K. Y. KIM Kangwon National University 192-1 Hyoja2-dong Chunchon-si Kangwon-do Republic of Korea To minimize processing efforts and avoid processing artifacts caused by extreme velocity gradients of shallow seismic data a quick and robust method utilizing optimum time windows varying with offset is proposed and applied to real data. The offset-variant optimum time window (OOTW) is defined as a time window where primary reflection signals are well separated from each other and isolated from shot-generated seismic noise. In the OOTW method seismic signals are stacked in the optimum
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Some Pitfalls Associated with Dominant Higher-Mode Surface-Wave Inversion
Authors A. O‘Neill, T. Matsuoka and K. TsukadaB028 SOME PITFALLS ASSOCIATED WITH DOMINANT HIGHER-MODE SURFACE-WAVE INVERSION 1 ADAM O’NEILL TOSHIFUMI MATSUOKA KAZUHIKO TSUKADA Department of Civil and Earth Resources Engineering Kyoto University Yoshida KYOTO 606-8501 Japan Low- and high-velocity layer dispersion Dominant higher modes of seismic surface waves are generated in low- and high-velocity layer cases typical of many engineering sites. Figure 1 shows three synthetic models and Figure 2 the ‘effective’ dispersion curves from full-waveform synthetic seismograms overlain on the plane-wave ‘modal’ dispersion curves. These types of dispersion curves both synthetically generated and observed at field sites were successfully inverted by linear optimisation using a forward
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3-D Multi-Component Shearwave Seismic – A New Tool for Near Surface Prospecting?
More LessB029 3-D MULTI-COMPONENT SHEARWAVE SEISMIC – A NEW TOOL FOR NEAR SURFACE PROSPECTING? Summary 1 We present a “true” 3-D shearwave refraction survey of an archaeological site in western Turkey performed for near surface basement mapping in a 1*1 m precision. Data were acquired in both three geophone and three shot components showing spectacular effects of wave propagation. Special wavefront processing and decomposition techniques were developed in order to handle effects of strong basement topography and refraction sideswipe. Introduction Geophysical work in the alluvial sedimentary environment of the archaeological site in Miletus' Lions' Harbour (Turkey) raised the question whether prominent
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Detection of Artificial Cavities Using Very High-Resolution Seismic
Authors O. Monnereau, J.L. Deherripont and C. BoulangerB030 DETECTION OF ARTIFICIAL CAVITIES USING VERY HIGH-RESOLUTION SEISMIC Introduction 1 O. MONNEREAU 1 J.L. DEHERRIPONT 2 C. BOULANGER 1 1 CGG France 1 rue Léon Migaux F-91341 Massy cedex 2 SNCF 6 avenue François Mitterand F-93574 La Plaine Saint Denis cedex In front of the problems related to the risk due to cavities (natural or artificial) on the TGV Nord Line (the High Speed Line Track in Northern France) SNCF (the French National Railway Company) developed a geophysical tests site on a siding that has the same structure as a traffic track in station TGV Haute-Picardie (figure 1) the
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From Shallow Land Seismic to Regional Geological Knowledge in the Aigion Active Fault Area, Gulf of Corinth, Greece
Authors P. Thierry, F. Lemeille and D. Sorel1 B031 FROM SHALLOW LAND SEISMIC TO REGIONAL GEOLOGICAL KNOWLEDGE IN THE AIGION ACTIVE FAULT AREA GULF OF CORINTH GREECE 1 2 3 P. THIERRY F. LEMEILLLE AND D. SOREL 1 Ecole des Mines de Paris Fontainebleau France 2 Institut de Radioprotection et de Sûreté Nucléaire Fontenay aux Roses France 3 Université Paris Sud Orsay France Summary We present the processing and the interpretation of a 2D shallow reflection seismic acquired in the vicinity of the Aigion active fault in the Gulf of Corinth Greece. This area is widely used in the frame of European projects to understand the whole
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Seismic Characterization of a Contaminated Site Using a Multi-Approach Technique
Authors G. Grandjean and A. BitriB032 SEISMIC CHARACTERIZATION OF A CONTAMINATED SITE USING A MULTI-APPROACH TECHNIQUE Introduction G.GRANDJEAN and A.BITRI BRGM BP 6009 Orléans France Since several decades numerous studies on contaminated sites have demonstrated that the physical characterization of the soils remains an important process that conditions the efficiency of remediation techniques. Improvement in safety and substantial cost savings can be realized with the appropriate use of geophysical methods. Of course the understanding of the limitations and applications of each method is critical to its success. As examples ground-penetrating radar is a suitable tool for delimiting the contamination plumes geometry (Grumman and Daniels 1995)
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Monitoring an Alternative De-Icer in Salt Contaminated Aquifer Using ERT
Authors T. Huotari, H. Vanhala, P. Hellstén and K. VaittinenB033 MONITORING AN ALTERNATIVE DE-ICER IN SALT CONTAMINATED AQUIFER USING ERT Summary 1 A new de-icer potassium formate was tested at a salt (NaCl) contaminated Kauriansalmi aquifer during winter 2002-2003. Electrical resistivity tomography (ERT) data was acquired 2002 and 2003 for mapping the geology of the area and for monitoring the effect of the alternative de-icer on the salt concentration of the groundwater. A 3-D model of the aquifer was formed using information carried out by ERT ground penetrating radar (GPR) borehole drillings and other available data. The bedrock topography model was a valuable tool in the interpretation of the
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Surface Geophysical Survey for Fly Ash Water Seepage Detection at Loy Yang Coal Mine
Authors A. Viezzoli, J.P. Cull and D. MassieB034 SURFACE GEOPHYSICAL SURVEY FOR FLY ASH WATER SEEPAGE DETECTION AT LOY YANG COAL MINE Summary 1 The fly ash water pond at Loy Yang Power station (Australia) presents high TDS content. It leaks into the shallow aquifer and affects groundwater quality. The existing boreholes monitoring network intercepts points of highly conductive groundwater but does not provide sufficient information on plume flow paths for remediation purposes. This paper reports the results of electrical and electromagnetic surface surveys applied to high resolution 3 D mapping of the seepage path. Galvanic and TEM techniques successfully identified the plume providing valuable information for
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Characterizing Tailings Impoundment at the Closed Hammaslahti Cu-Zn Mine, Finland
Authors H. Vanhala, M.-L. Räisänen, T. Huotari, T. Valjus, J. Lehtimäki and I. SuppalaB035 CHARACTERIZING TAILINGS IMPOUNDMENT AT THE CLOSED HAMMASLAHTI CU-ZN MINE FINLAND Summary 1 *H.VANHALA 1 M-L.RÄISÄNEN 2 T.HUOTARI 1 T.VALJUS 1 J. LEHTIMÄKI 1 and I. SUPPALA 1 1 Geological Survey of Finland (GTK) Betonimiehenkuja 4 FIN-02150 Espoo Finland Acid mine drainage (AMD) results when sulphide bearing tailings sand is exposed to air and water. Oxidation of sulphide minerals and release of acid and dissolved metals in tailings impoundments can last for tens to hundreds of years. Rehabilitation risk analysis and risk assessment of the old tailings impoundments require detailed information on the structure mineralogy and chemistry as well as
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Interdisciplinary Waste Site Investigation in Balassagyarmat / Hungary (NORISC-Project)
More LessB036 INTERDISCIPLINARY WASTE SITE INVESTIGATION IN BALASSAGYARMAT / HUNGARY (NORISC-PROJECT) 1 M. PERK° B. TEZKAN° A. HÖRDT^ AND THE NORISC TEAM ° Institute f. Geophysics & Meteorology University of Cologne ^ Geological Institute Department of Applied Geophysics University Bonn Introduction Within the NORISC-project (Network-Oriented Risk-assessment by In-Situ screening of Contaminated sites; www.norisc.com) which is part of the 5.the framework programme of the EU for Energy environment and sustainable development a tool for city planers engineering offices und environmental offices was developed to investigate waste sites in a effective time- and costreducing way compared to standard investigations. Different methods from various
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Geophysical Investigations of a Waste Disposal in Urban Environment
Authors D. Fielitz and M. DegutschB037 GEOPHYSICAL INVESTIGATIONS OF A WASTE DISPOSAL IN URBAN ENVIRONMENT 1 DANIEL FIELITZ MANFRED DEGUTSCH Institute of Geophysics Corrensstr. 24 48149 Muenster email: [email protected] Abstract An extended geophysical survey using magnetic resistivity and seismic methods has been carried out in a complicated area in the city of Muenster. The purpose was to map the boundary between an old waste disposal site and the underlying “Muensterlaender Kiessandzug”. The results reveal that the disposal extends to a depth of approximately 15m with resistivity values between 70 Ohm*m and 200 Ohm*m and p-velocities ranging from 400 m/s to 600 m/s. Introduction The aim
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The Use of Borehole Radar Tomography to Monitor a Steam Injection Pilot Study in a Contaminated Fractured Limestone (Maine, USA)
Authors C. Grégoire, J.W. Lane and P.K. JoestenB038 THE USE OF BOREHOLE RADAR TOMOGRAPHY TO MONITOR A STEAM INJECTION PILOT STUDY IN A CONTAMINATED FRACTURED LIMESTONE (MAINE USA) 1 Colette Grégoire (*) John W. Lane Jr. (**) and Peter K. Joesten (**) (*) KULeuven Department Civil Engineering Kasteelpark Arenberg 40 3001 Leuven Belgium [email protected] (**) U.S. Geological Survey Branch of Geophysics 11 Sherman Place Unit 5015 Storrs Mansfield CT 06269 United States Abstract Steam-enhanced remediation (SER) has been successfully used to remove DNAPL and LNAPL contaminants from porous media. Between August and November of 2002 SER was tested in a fractured limestone at the former Loring Air
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Application of Geophysical Methods for Detection of Cavities in Khalifa City (B) of Abu Dhabi Emirate, U.A.E.
Authors B. Li, A. Taleb and H. Al JafriP001 APPLICATION OF GEOPHYSICAL METHODS FOR DETECTION OF CAVITIES IN KHALIFA CITY (B) OF ABU DHABI EMIRATE U.A.E. 1 Introduction Cavities have been encountered during the construction of infrastructure in Khalifa City (B) Emirate of Abu Dhabi. Heavy groundwater flow through cavities delayed the works for months and resulted in claim by contractors. Moreover cavities are considered hazardous to the future building structures. A geotechnical investigation involving boreholes laboratory test and geophysical survey has been conducted in Khalifa City (B) since 1999. Approximately 1100 line kilometer of geophysical survey has been completed. An integrated risk map has been produced classifying
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Oil Polluted Zones Mapping by Geoelectric Methods
Authors N.A. Yakymchuk, S.P. Levashov, I.N. Korchagin and J.M. PyschaniyP002 OIL POLLUTED ZONES MAPPING BY GEOELECTRIC METHODS 1 S.P. LEVASHOV 1 N.A. YAKYMCHUK 1 I.N. KORCHAGIN 2 JU.M. PYSCHANIY 2 1 Institute of applied problems of Ecology Geophysics and Geochemistry Laboratory lane 1 Kyiv 01133 Ukraine e-mail: [email protected] [email protected] 2 Institute of Geophysics of Ukraine National Academy of Science e-mail: [email protected] Abstract. This paper provides the results of applying the technology of identifying and contouring sections polluted by oil by means of geoelectric methods. The technology enables us to mark out zones of tectonic disruptions on examined sections; map zones polluted by oil and identify the ways of a
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Refraction Seismic Survey to Evaluate the Danger of Ground Surface Damage in Mining Areas
By J.A. DecP003 REFRACTION SEISMIC SURVEY TO EVALUATE THE DANGER OF GROUND SURFACE DAMAGE IN MINING AREAS 1 Abstract Extensive seismic survey was carried out over the mining area of the Katowice-Kleofas coal mine in Katowice Poland. The survey covered the area of old shallow workings which pose the risk of ground surface damage. The aims of the survey included evaluation of properties of rocks occurring beneath the Carboniferous top evaluation of the continuity of the Carboniferous top surface and evaluation of the risk of surface damage. The Carboniferous rocks are covered by Quaternary deposits: loamy sands and clays of a few
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Large-Scale Geophysical Studies in the Legio IV Scythica in Zeugma-Turkey
Authors M.G. Drahor, M. Hartmann and M.A. SpiedelP004 LARGE-SCALE GEOPHYSICAL STUDIES IN THE LEGIO IV SCYTHICA IN ZEUGMA-TURKEY Abstract 1 MAHMUT G. DRAHOR 1 MARTIN HARTMANN 2 AND MICHAEL A. SPIEDEL 2 * Dokuz Eylül University Engineering Faculty Dept. Of Geophysics 35160 Kaynaklar Campus Buca-Izmir/Turkey + HIstorIsches InstItut Abt. Alte GeschIchte u. EpIgraphIk Länggassstr. 49 CH-3000 Bern 9 / Switzerland. Zeugma was the most important city between the Mesopotamia and Mediterranean in the antique era and the city was also the main passing point in the Euphrates River. Zeugma and Apameia city were at the opposite sites of the river Euphrates and these cities were established in
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GPR and ERT – Integrated Geophysical Methods in Archaeology
Authors L. Baradello, A. Bratus and D.N. YabarP005 GPR AND ERT – INTEGRATED GEOPHYSICAL METHODS IN ARCHAEOLOGY Abstract 1 This work is a case history about an archaeological survey with two geophysical integrated methods: Ground Penetrating Radar and Electrical Resistivity Tomography. The principal objective of our research was to detect the ruins of a medieval castle in Friuli a north-east region of Italy. Introduction Ground Penetrating Radar (GPR) is a high resolution electromagnetic technique used for identifying possible buried objects in shallow investigations (Davis and Annan 1989). For this motive GPR is often employed in archaeological field for the search of ancient ruins walls and human manufactured
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The Use of Geophysical Methods in the Investigation of Subsurface Waters in Albania
Authors L.L. Lleshi and V. AzizajP006 THE USE OF GEOPHYSICAL METHODS IN THE INVESTIGATION OF SUBSURFACE WATERS IN ALBANIA 1 LL. LLESHI 1 V. AZIZAJ 1 1 Geophysical Center of Tirana L.9 Blloku Vasil Shanto Tirana Albania Introduction The geophysical methods and particularly the electrical methods are widely used in the investigation of subsurface waters in many regions of Albania. Last years the growth of demography and the need of community for drinking -water has led to the increase of the geophysical explorations carried out in the service of hydrogeology. Nowadays the most part of geophysical explorations consists in this research topic. In this paper
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Monitoring Tracer Experiments at the Krauthausen Test Site Using Time-Lapse ERT
Authors A. Kemna, J. Vanderborght, K. Borgers, K. Gößling, A. Verweerd, A. Englert, K. Müller and H. VereeckenP007 MONITORING TRACER EXPERIMENTS AT THE KRAUTHAUSEN TEST SITE USING TIME- LAPSE ERT Abstract 1 Time-lapse electrical resistance tomography (ERT) has proven significant potential to image solute plumes in the subsurface. We here report on the use of time-lapse ERT to monitor two tracer experiments conducted in a heterogeneous aquifer at the Krauthausen test site Germany. The two experiments were carried out under similar hydrological boundary conditions but one time with an electrically conductive (“positive”) tracer the other time with a resistive (“negative”) tracer. Based on earlier synthetic studies on the capability of 2D ERT imaging to characterize 3D transport
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Estimate of the Aperture of Watersaturated Fractures by Nuclear Magnetic Resonance Logging
Authors Y. Nakashima and T. KikuchiP008 ESTIMATE OF THE APERTURE OF WATER- SATURATED FRACTURES BY NUCLEAR MAGNETIC RESONANCE LOGGING Abstract 1 Nuclear magnetic resonance (NMR) well logging is a technique to measure the transport properties of fluid-saturated porous strata by analyzing the proton NMR signals from the hydrogen-bearing fluid molecules. We applied the technique to a borehole in an andesite lava formation (Akita Japan) to estimate the aperture of fractures embedded in the lava. A fracture (depth 61.2 m) responsible for the total loss of circulation during the drilling was scanned by a Schlumberger NMR sonde to obtain the bulk-fluid porosity of the fracture filled
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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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