- Email: [email protected]
Seismic instrumentation of landslides: building a better model of dynamic landslide behavior
SITE 1NVESTIGATIONS:MONITORING radioactivity are present: i.e. potassium, uranium and thorium. The influence of borehole conditions on the calibration factors are discussed. (from Author) 963226 An empirical model to determine the gamma-ray detection enrlciency for an 81 cm’ HPGe detector in a borehole environment in the photon energy region 0.746 MeV R. A. M. Rizk, A. M. A. El-Sayed, E. E. Abdel-Hady t A. M. Mohamed, Nuclear Geophysics, 9(2), 1995, pp 99-106. It was found that the efficiency curves derived can well be represented empirically by a Cauchy polynomial. The polynomials derived can be immediately applied to predict the relative efficiency values without the need to perform Monte Carlo calculations or additional experiments. (from Authors)
Processing and interpretation of data 963227 Large-scale mineral potential estimation for blind precious metal ore bodies Guocheng Pan & B. Porterfield, Nonrenewable Resources, 4(2), 1995, pp 187-207. A comprehensive methodology is proposed for large-scale mineral exploration. The central information synthesizer is canonical or indicator favorability analysis. A case study is presented involving a gold-mining district where step-out drilling targets are being sought to expand the resource base. Several drilling targets were delineated. Two were tested with positive results. (from Authors) 963228 Sampling and statistical evaluation of diamond deposits L. Rombouts, Journal of Geochemical Exploration, 53(1-3), 1995, pp 351-367. An analysis of the statistical distribution of the stone sizes, occurrences and values is essential for calculating the confidence limits on the estimated averages. If variables are lognormally distributed, a more efficient estimator, such as the t-estimator, can be used, instead of the arithmetic mean. Knowledge of the statistical distribution is also useful when microdiamond counts from early stage exploration drilling are used to make preliminary estimates of potential grades of commercial-sized diamonds. (from Author) 963229 Computerized field-data capture and GIS analysis for generation of cross sections in 3-D perspective views E. M. Schetselaar, Computers & Geosciences, 21(5), 1995, pp 687-701. A method for field-data capture and Geographic Information System analysis for representation of cross sections in 3-D is discussed, in which digital storage and management of fieldcollected structural elements facilitates GIS analytical processing and visualization. Raster-to-point, vector-to-point conversions and spreadsheet calculations were combined in a batch-routine to generate displays of cross sections with projected structural elements stacked in perspective views. The method demonstrates how 2-D GIS software can be exploited for 3-D visualization of geologic structures. (Author) 963230 Dislocational rock mechanics as a basis for seismic methods in the search for hydrocarbons V. B. Pissetski, Revue - Znstitut Francais du Petrole, 50(3), 1995, pp 303-336. The information contained here reflects a conceptual framework based on the discrete character of sedimentary media. In a given medium, this discrete structure causes a specific type of behaviour in response to the mechanical stresses operating in the Barth’s crust, thus defining the set of physical parameters of the system. The main elements of this frame-
work are described. A method for interpreting seismic data is then established. It illustrates the possibility of successfully predicting patterns of fluid migration and accumulation and confirms the genera1 relations governing variations in dislocational structure and pressure in sedimentary basins. (from Author)
963231 Importance of multiple suppression in seismic exploration J. 0. Ebeniro, Journal of Mining & Geology, 29(2), 1993(1995), pp 183-193. Although several specialized processing techniques have been developed for multiple suppression, common-mid-point stacking is the most common technique for suppressing multiples. It is shown that specific techniques for multiple suppression of any seismic data are necessary before any meaningful interpretation and subsequent analysis of the data is made. Stacking should be used as part of the cascading effort needed to improve the quality of the data after application of other multiple suppression processing techniques. (from Author)
963232 A new method of quantitative interpretation of SP anomalies produced by a polarized inclined skeet G. Skianis, T. Papadopoulos, D. Vaiopoulos L S. Nikolaou, Geophysical Prospecfing, 43(5), 1995, pp 677-691. A new method is proposed for the quantitative interpretation of SP field data produced by a polarized ore body and simulated by an inclined sheet. The theoretical concept is based on the study of the amplitude spectrum. The maximum amplitude spectrum value of the SP gradient is used to estimate the depth to the bottom of the polarized body. Thus, the geometrical parameters h and H, the depths to the top and bottom, respectively, as well as the dip angle of the inclined sheet, can be satisfactorily determined. (from Authors)
963233 Understanding telluric distortion matrices J. T. Smith, Geophysical Journal International, 122(l), 1995, pp 219-226. Telluric distortion occurs when electric charges accumulate along near-surface inhomogeneities. Practical parametrizations of a telluric distortion matrix separate it into recoverable and non-recoverable parameters. A very simple parametrization used by Bahr (1988) does this, and is easily interpreted in terms of rotations and amplifications of the regional electric field components aligned with the regional strike directions. Groom & Bailey’s (1989) parametrization is equivalent, but more complicated. Optimal estimates of the electric field rotations, the regional strike, and scaled regional impedances are made easily using the simple parametrization advocated in this paper. (from Author)
Monitoring rock and soil mass performance 963234 Seismic instrumentation of landslides: building a better model of dynamic landslide behavior E. L. Harp & R. W. Jibson, Bulletin - Seismological Society of America, 85(l), 1995, pp 93-99. Two permanent instrument arrays have been installed on seismically active landslides to simultaneously record acceleration, pore pressure, and permanent landslide displacement, which will permit more accurate modeling of seismic landslide response (from Authors)
Processing and interpretation of data 963227 Large-scale mineral potential estimation for blind precious metal ore bodies Guocheng Pan & B. Porterfield, Nonrenewable Resources, 4(2), 1995, pp 187-207. A comprehensive methodology is proposed for large-scale mineral exploration. The central information synthesizer is canonical or indicator favorability analysis. A case study is presented involving a gold-mining district where step-out drilling targets are being sought to expand the resource base. Several drilling targets were delineated. Two were tested with positive results. (from Authors) 963228 Sampling and statistical evaluation of diamond deposits L. Rombouts, Journal of Geochemical Exploration, 53(1-3), 1995, pp 351-367. An analysis of the statistical distribution of the stone sizes, occurrences and values is essential for calculating the confidence limits on the estimated averages. If variables are lognormally distributed, a more efficient estimator, such as the t-estimator, can be used, instead of the arithmetic mean. Knowledge of the statistical distribution is also useful when microdiamond counts from early stage exploration drilling are used to make preliminary estimates of potential grades of commercial-sized diamonds. (from Author) 963229 Computerized field-data capture and GIS analysis for generation of cross sections in 3-D perspective views E. M. Schetselaar, Computers & Geosciences, 21(5), 1995, pp 687-701. A method for field-data capture and Geographic Information System analysis for representation of cross sections in 3-D is discussed, in which digital storage and management of fieldcollected structural elements facilitates GIS analytical processing and visualization. Raster-to-point, vector-to-point conversions and spreadsheet calculations were combined in a batch-routine to generate displays of cross sections with projected structural elements stacked in perspective views. The method demonstrates how 2-D GIS software can be exploited for 3-D visualization of geologic structures. (Author) 963230 Dislocational rock mechanics as a basis for seismic methods in the search for hydrocarbons V. B. Pissetski, Revue - Znstitut Francais du Petrole, 50(3), 1995, pp 303-336. The information contained here reflects a conceptual framework based on the discrete character of sedimentary media. In a given medium, this discrete structure causes a specific type of behaviour in response to the mechanical stresses operating in the Barth’s crust, thus defining the set of physical parameters of the system. The main elements of this frame-
work are described. A method for interpreting seismic data is then established. It illustrates the possibility of successfully predicting patterns of fluid migration and accumulation and confirms the genera1 relations governing variations in dislocational structure and pressure in sedimentary basins. (from Author)
963231 Importance of multiple suppression in seismic exploration J. 0. Ebeniro, Journal of Mining & Geology, 29(2), 1993(1995), pp 183-193. Although several specialized processing techniques have been developed for multiple suppression, common-mid-point stacking is the most common technique for suppressing multiples. It is shown that specific techniques for multiple suppression of any seismic data are necessary before any meaningful interpretation and subsequent analysis of the data is made. Stacking should be used as part of the cascading effort needed to improve the quality of the data after application of other multiple suppression processing techniques. (from Author)
963232 A new method of quantitative interpretation of SP anomalies produced by a polarized inclined skeet G. Skianis, T. Papadopoulos, D. Vaiopoulos L S. Nikolaou, Geophysical Prospecfing, 43(5), 1995, pp 677-691. A new method is proposed for the quantitative interpretation of SP field data produced by a polarized ore body and simulated by an inclined sheet. The theoretical concept is based on the study of the amplitude spectrum. The maximum amplitude spectrum value of the SP gradient is used to estimate the depth to the bottom of the polarized body. Thus, the geometrical parameters h and H, the depths to the top and bottom, respectively, as well as the dip angle of the inclined sheet, can be satisfactorily determined. (from Authors)
963233 Understanding telluric distortion matrices J. T. Smith, Geophysical Journal International, 122(l), 1995, pp 219-226. Telluric distortion occurs when electric charges accumulate along near-surface inhomogeneities. Practical parametrizations of a telluric distortion matrix separate it into recoverable and non-recoverable parameters. A very simple parametrization used by Bahr (1988) does this, and is easily interpreted in terms of rotations and amplifications of the regional electric field components aligned with the regional strike directions. Groom & Bailey’s (1989) parametrization is equivalent, but more complicated. Optimal estimates of the electric field rotations, the regional strike, and scaled regional impedances are made easily using the simple parametrization advocated in this paper. (from Author)
Monitoring rock and soil mass performance 963234 Seismic instrumentation of landslides: building a better model of dynamic landslide behavior E. L. Harp & R. W. Jibson, Bulletin - Seismological Society of America, 85(l), 1995, pp 93-99. Two permanent instrument arrays have been installed on seismically active landslides to simultaneously record acceleration, pore pressure, and permanent landslide displacement, which will permit more accurate modeling of seismic landslide response (from Authors)