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Integrating seismic, resistivity, and ground penetrating radar to delineate the water table and groundwater contamination
362A
936233 Reconnaissance profiles with WLP in complex geological regions Michon, D J Appl Geophys V29, N3/4, April 1993, P285-300 Three-dimensional analysis of seismic survey data is commonplace in reservoir characterisation but may be difficult to apply and expensive for crustal seismic exploration on a large scale. The Wide Line Profiling technique is an attractive and cost effective method for the latter case. The processing method of the WLP is described. A series of examples illustrates its advantages over standard processing methods.
936234 Simultaneous observation of seismic waves of different polarization indicates subsurface anisotropy and might help to unravel its cause Helbig, K J Appl Geophys V30, N1/2, April 1993, P1-24 Isotropy in real geological media is the special case rather than the norm. Fundamental aspects of anisotropy are described and the classification of elastic anisotropy and basic differences in wave propagation in isotropic and anisotropic media are examined. The advent of anisotropy in exploration seismics is considered. The nature of seismic anisotropy, the causes of anisotropy and their relation to other parameters, and the possibility of deducing the causes of anisotropy from observable effects are discussed. Some interpretational aspects of seismic anisotropy are presented.
936235 Rapid, high-accuracy electromagnetic soundings using a novel four-axis coil to measure magnetic field ellipticity Bak, N H; Sternberg, B K; Dvorak, S L; Thomas, S J J Appl Geophys 1130, N3, May 1993, P235-245 A high resolution electromagnetic sounding system with a four-axis coil and a new calibration technique is described. Resulting measurements have an accuracy of +/-0.1%. The four-axis coil has 3 approximately orthogonal coils detecting 3 components of the magnetic field and a calibration coil which injects a calibration signal simultaneous with data collection. A program to compute ellipticity without knowing absolute coil orientation has been developed. The instrument is capable of measuring very small temporal changes, such as required in monitoring groundwater contaminant plumes.
936236 Three-dimensional structure of Kilauea volcano, Hawaii, from travel time tomography Rowan, L R; Clayton, R W J Geophys Res V98, NB3, March 1993, P4355-4375 A linear travel time tomography study has been made of the worlds most active shield volcano to determine the lateral heterogeneities produced by the intricate magmatic and tectonic environment. The existing dense seismograph network and high local seismicity allow excellent coverage of the complex subsurface features. Data description and processing methods, resolution, and errors in the data and the model are discussed. Details of Kilauea summit, rift zones, and the fault systems are illustrated.
936237 Field measurements contribution to development of Ein Furtaga as water resources, southern Sinai, Egypt Helal, H Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V2, P553-559. Publ Rotterdam." A A Balkema, 1991 Ein Furtaga is the largest spring in the south east of Sinai. Water issues from fractured zones in crystalline basement rocks over a length of about 6.5km. Geotechnical study of the joint and fissure system, structural geological examination, and vertical resistivity soundings were carried out as part of a program to maximise the utilisation of this water source. Optimum zones for siting of collection wells were identified.
936238 Integrating seismic, resistivity, and ground penetrating radar to delineate the water table and groundwater contamination Benson, A K Proc 7th International Symposium on Water-Rock Interaction, Park City, 13-18 July 1992 V1, P361-365. Publ Rotterdam: A A Balkema, 1992 A combination of geophysical techniques can be used to map the water table and groundwater contamination. Seismic refraction provides hydrological and geological cross sections of shallow alluvial aquifers. Resistivity and GPR responses are sensitive to the quality of the pore fluids. GPR data indicate approximate boundaries of the contaminant plume and provide additional stratigraphic data for the site. Geometry, source, and amount of contamination can be estimated using resistivity sounding surveys. Case study details illustrate the advantages of this integrated approach.
936239 Electromagnetic induction and seismic refraction surveys to detect bedrock pinnacles Jansen, J; Anklam, J; Goodwin, C; Roof, A Proc 4th Muitidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts o f Karst, Panama City, Florida, 25-27 January 1993 Pl15-122. Publ Rotterdam. A A Balkema, 1993 Electromagnetic induction and seismic refraction surveys were carried out at a landfill expansion site in Wisconsin, where 612m of clayey residual soil overlie Oneota dolomite, which is moderately susceptible to karst processes. The surveys, followed by limited test drilling, successfully delineated one bedrock pinnacle and indicated others. Modifications to improve correlation between EM anomalies and apparent seismic pinnacles are underway. The final survey will guide, not replace, intensive drilling programs.
936240 Verification of seismic tomogram interpretation by finite element analysis Su, D W H; Cotten, S A Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P1009-1018. Publ Rotterdam: A A Balkema, 1992 2D and 3D finite element analyses were used to verify interpretation of a crosshole seismic survey to locate a flooded abandoned coal mine. An elastoplastic strain softening model was used for the nonlinear rock mass and interface elements for discontinuities. Good agreement is found for stress distributions predicted by the two approaches. Fractures around the mined-out zone were not well delineated by the numerical modelling, presumably because the saturated fracture zones are not primary parameters controlling seismic wave propagation.
© 1993 Pergamon Press Ltd. Reproduction not permitted
936233 Reconnaissance profiles with WLP in complex geological regions Michon, D J Appl Geophys V29, N3/4, April 1993, P285-300 Three-dimensional analysis of seismic survey data is commonplace in reservoir characterisation but may be difficult to apply and expensive for crustal seismic exploration on a large scale. The Wide Line Profiling technique is an attractive and cost effective method for the latter case. The processing method of the WLP is described. A series of examples illustrates its advantages over standard processing methods.
936234 Simultaneous observation of seismic waves of different polarization indicates subsurface anisotropy and might help to unravel its cause Helbig, K J Appl Geophys V30, N1/2, April 1993, P1-24 Isotropy in real geological media is the special case rather than the norm. Fundamental aspects of anisotropy are described and the classification of elastic anisotropy and basic differences in wave propagation in isotropic and anisotropic media are examined. The advent of anisotropy in exploration seismics is considered. The nature of seismic anisotropy, the causes of anisotropy and their relation to other parameters, and the possibility of deducing the causes of anisotropy from observable effects are discussed. Some interpretational aspects of seismic anisotropy are presented.
936235 Rapid, high-accuracy electromagnetic soundings using a novel four-axis coil to measure magnetic field ellipticity Bak, N H; Sternberg, B K; Dvorak, S L; Thomas, S J J Appl Geophys 1130, N3, May 1993, P235-245 A high resolution electromagnetic sounding system with a four-axis coil and a new calibration technique is described. Resulting measurements have an accuracy of +/-0.1%. The four-axis coil has 3 approximately orthogonal coils detecting 3 components of the magnetic field and a calibration coil which injects a calibration signal simultaneous with data collection. A program to compute ellipticity without knowing absolute coil orientation has been developed. The instrument is capable of measuring very small temporal changes, such as required in monitoring groundwater contaminant plumes.
936236 Three-dimensional structure of Kilauea volcano, Hawaii, from travel time tomography Rowan, L R; Clayton, R W J Geophys Res V98, NB3, March 1993, P4355-4375 A linear travel time tomography study has been made of the worlds most active shield volcano to determine the lateral heterogeneities produced by the intricate magmatic and tectonic environment. The existing dense seismograph network and high local seismicity allow excellent coverage of the complex subsurface features. Data description and processing methods, resolution, and errors in the data and the model are discussed. Details of Kilauea summit, rift zones, and the fault systems are illustrated.
936237 Field measurements contribution to development of Ein Furtaga as water resources, southern Sinai, Egypt Helal, H Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V2, P553-559. Publ Rotterdam." A A Balkema, 1991 Ein Furtaga is the largest spring in the south east of Sinai. Water issues from fractured zones in crystalline basement rocks over a length of about 6.5km. Geotechnical study of the joint and fissure system, structural geological examination, and vertical resistivity soundings were carried out as part of a program to maximise the utilisation of this water source. Optimum zones for siting of collection wells were identified.
936238 Integrating seismic, resistivity, and ground penetrating radar to delineate the water table and groundwater contamination Benson, A K Proc 7th International Symposium on Water-Rock Interaction, Park City, 13-18 July 1992 V1, P361-365. Publ Rotterdam: A A Balkema, 1992 A combination of geophysical techniques can be used to map the water table and groundwater contamination. Seismic refraction provides hydrological and geological cross sections of shallow alluvial aquifers. Resistivity and GPR responses are sensitive to the quality of the pore fluids. GPR data indicate approximate boundaries of the contaminant plume and provide additional stratigraphic data for the site. Geometry, source, and amount of contamination can be estimated using resistivity sounding surveys. Case study details illustrate the advantages of this integrated approach.
936239 Electromagnetic induction and seismic refraction surveys to detect bedrock pinnacles Jansen, J; Anklam, J; Goodwin, C; Roof, A Proc 4th Muitidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts o f Karst, Panama City, Florida, 25-27 January 1993 Pl15-122. Publ Rotterdam. A A Balkema, 1993 Electromagnetic induction and seismic refraction surveys were carried out at a landfill expansion site in Wisconsin, where 612m of clayey residual soil overlie Oneota dolomite, which is moderately susceptible to karst processes. The surveys, followed by limited test drilling, successfully delineated one bedrock pinnacle and indicated others. Modifications to improve correlation between EM anomalies and apparent seismic pinnacles are underway. The final survey will guide, not replace, intensive drilling programs.
936240 Verification of seismic tomogram interpretation by finite element analysis Su, D W H; Cotten, S A Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P1009-1018. Publ Rotterdam: A A Balkema, 1992 2D and 3D finite element analyses were used to verify interpretation of a crosshole seismic survey to locate a flooded abandoned coal mine. An elastoplastic strain softening model was used for the nonlinear rock mass and interface elements for discontinuities. Good agreement is found for stress distributions predicted by the two approaches. Fractures around the mined-out zone were not well delineated by the numerical modelling, presumably because the saturated fracture zones are not primary parameters controlling seismic wave propagation.
© 1993 Pergamon Press Ltd. Reproduction not permitted