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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 - 20 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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