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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
41 - 60 of 132 results
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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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