Research article
04 Nov 2014
Research article
| 04 Nov 2014
Large-scale 3-D modeling by integration of resistivity models and borehole data through inversion
N. Foged et al.
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The transient electromagnetic method (TEM) is widely used for mapping subsurface resistivity structures, but data are inevitably contaminated by noise from various sources including radio signals in the very low frequency (VLF) 3–30 kHz band. We present an approach where VLF noise is effectively suppressed with a new post-processing scheme where boxcar gates are combined into semi-tapered gates. The result is a 20 % increase in the depth of investigation for the presented test survey.
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In the McMurdo Dry Valleys of Antarctica, a deep groundwater system has been hypothesized to connect Don Juan Pond and Lake Vanda, both surface waterbodies that contain very high concentrations of salt. This is unusual, since permafrost in polar landscapes is thought to prevent subsurface hydrologic connectivity. We show results from an airborne geophysical survey that reveals widespread unfrozen brine in Wright Valley, and points to the potential for deep valley-wide brine conduits.
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Hydrol. Earth Syst. Sci., 26, 2813–2827, https://doi.org/10.5194/hess-26-2813-2022, https://doi.org/10.5194/hess-26-2813-2022, 2022
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Lake Fryxell, Antarctica, has undergone hundreds of meters of change in recent geologic history. However, there is disagreement on when lake levels were higher and by how much. This study uses resistivity data to map the subsurface conditions (frozen versus unfrozen ground) to map ancient shorelines. Our models indicate that Lake Fryxell was up to 60 m higher just 1500 to 4000 years ago. This amount of lake level change shows how sensitive these systems are to small changes in temperature.
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The transient electromagnetic method (TEM) is widely used for mapping subsurface resistivity structures, but data are inevitably contaminated by noise from various sources including radio signals in the very low frequency (VLF) 3–30 kHz band. We present an approach where VLF noise is effectively suppressed with a new post-processing scheme where boxcar gates are combined into semi-tapered gates. The result is a 20 % increase in the depth of investigation for the presented test survey.
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Within the framework of the EU project IMPROWARE, our goal was to investigate a Mediterranean coastal aquifer in Egypt and develop scenarios for artificial aquifer remediation and recharge. The results of an extensive hydrogeophysical investigation were successfully used as an input in regional and local hydrological models to understand the hydrological evolution of the area. The research outcomes clearly highlight the effectiveness of using advanced geophysical and modeling methodologies.
P. A. Marker, N. Foged, X. He, A. V. Christiansen, J. C. Refsgaard, E. Auken, and P. Bauer-Gottwein
Hydrol. Earth Syst. Sci., 19, 3875–3890, https://doi.org/10.5194/hess-19-3875-2015, https://doi.org/10.5194/hess-19-3875-2015, 2015
X. L. He, T. O. Sonnenborg, F. Jørgensen, and K. H. Jensen
Hydrol. Earth Syst. Sci., 18, 2943–2954, https://doi.org/10.5194/hess-18-2943-2014, https://doi.org/10.5194/hess-18-2943-2014, 2014
C. I. Michailovsky and P. Bauer-Gottwein
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Hydrol. Earth Syst. Sci., 17, 4043–4060, https://doi.org/10.5194/hess-17-4043-2013, https://doi.org/10.5194/hess-17-4043-2013, 2013
X. He, T. O. Sonnenborg, F. Jørgensen, A.-S. Høyer, R. R. Møller, and K. H. Jensen
Hydrol. Earth Syst. Sci., 17, 3245–3260, https://doi.org/10.5194/hess-17-3245-2013, https://doi.org/10.5194/hess-17-3245-2013, 2013
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Cited articles
Archie, G. E.: The electrical resistivity log as an aid in determining some reservoir characteristics, Trans. AIME, 146, 54–62, 1942.
Auken, E. and Christiansen, A. V.: Layered and laterally constrained 2-D inversion of resistivity data, Geophysics, 69, 752–761, 2004.
Auken, E., Christiansen, A. V., Jacobsen, B. H., Foged, N., and Sørensen, K. I.: Piecewise 1-D Laterally Constrained Inversion of resistivity data, Geophys. Prospect., 53, 497–506, 2005.
Auken, E., Christiansen, A. V., Westergaard, J. A., Kirkegaard, C., Foged, N., and Viezzoli, A.: An integrated processing scheme for high-resolution airborne electromagnetic surveys, the SkyTEM system, Explor. Geophys., 40, 184–192, 2009.
Auken, E., Christiansen, A. V., Kirkegaard, C., Fiandaca, G., Schamper, C., Behroozmand, A. A., Binley, A., Nielsen, E., Effersø, F., Christensen, N. B., Sørensen, K. I., Foged, N., and Vignoli, G.: An overview of a highly versatile forward and stable inverse algorithm for airborne, ground-based and borehole electromagnetic and electric data, Explor. Geophys., 1–13, https://doi.org/10.1071/EG13097, 2014.
Bussian, A. E.: Electrical conductance in a porous medium, Geophysics, 48, 1258–1268, 1983.
Carle, S. F. and Fogg, G. E.: Transition Probability-Based Indicator Geostatistics, Mathematical Geology, 28, 453–476, 1996.
Christiansen, A. V. and Auken, E.: A global measure for depth of investigation, Geophysics, 77, 4, WB171–WB177, 2012.
Christiansen, A. V., Foged, N., and Auken, E.: A concept for calculating accumulated clay thickness from borehole lithological logs and resistivity models for nitrate vulnerability assessment, J. Appl. Geophys., 108, 69–77, 2014.
Clavier, C., Coates, G., and Dumanoir, J.: Theoretical and experimental bases for the dual-water model for interpretation of shaly sands, Soc. Petrol. Eng. J., 24, 153–168, 1984.
Daly, C. and Caers, J. K.: Multi-point geostatistics – an introductory overview, First Break, 28, 39–47, 2010.
Dam, D. and Christensen, S.: Including geophysical data in ground water model inverse calibration, Ground Water, 41, 178–189, 2003.
Deutsch, C. V. and Journel, A. G.: GSLIB: geostatistical software library and user's guide, Second edition, Oxford University Press, 1998.
Geonics Limited, http://www.geonics.com/index.html (last acces: 29 October 2014), 2012.
Halkidi, M., Batistakis, Y., and Vazirgiannis, M.: Clustering validity checking methods: Part II, Sigmod Record, 31, 19–27, 2002.
Härdle, K. W. and Simar, L.: Applied Multivariate Statistical Analysis, Springer, 2012.
He, X., Koch, J., Sonnenborg, T. O., Jørgensen, F., Schamper, C., and Refsgaard, J. C.: Transition probability based stochastic geological modeling using airborne geophysical data and borehole data: Water Resour. Res., Special Issue on Patterns in Soil-Vegetation-Atmosphere Systems, Monitoring, Modeling and Data Assimilation, 50, 3147–3169, https://doi.org/10.1002/2013WR014593, 2014.
Herckenrath, D., Fiandaca, G., Auken, E., and Bauer-Gottwein, P.: Sequential and joint hydrogeophysical inversion using a field-scale groundwater model with ERT and TDEM data, Hydrol. Earth Syst. Sci., 17, 4043–4060, https://doi.org/10.5194/hess-17-4043-2013, 2013.
Hinnell, A. C., Ferre, T. P. A., Vrugt, J. A., Huisman, J. A., Moysey, S., Rings, J., and Kowalsky, M. B.: Improved extraction of hydrologic information from geophysical data through coupled hydrogeophysical inversion, Water Resour. Res., 46, https://doi.org/10.1029/2008WR007060, 2010.
Høyer, A.-S., Jørgensen, F., Lykke-Andersen, H., and Christiansen, A. V.: Iterative modelling of AEM data based on geological a priori information from seismic and borehole data, Near Surf. Geophys., 12, 635–650, https://doi.org/10.3997/1873-0604.2014024, 2014.
Jørgensen, F. and Sandersen, P. B. E.: Buried and open tunnel valleys in Denmark-erosion beneath multiple ice sheets, Quaternary Sci. Rev., 25, 1339–1363, 2006.
Jørgensen, F., Scheer, W., Thomsen, S., Sonnenborg, T. O., Hinsby, K., Wiederhold, H., Schamper, C., Burschil, T., Roth, B., Kirsch, R., and Auken, E.: Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise, Hydrol. Earth Syst. Sci., 16, 1845–1862, https://doi.org/10.5194/hess-16-1845-2012, 2012.
Jørgensen, F., Møller, R. R., Nebel, L., Jensen, N., Christiansen, A. V., and Sandersen, P.: A method for cognitive 3-D geological voxel modelling of AEM data, B. Eng. Geol. Environ., 72, 421–432, https://doi.org/10.1007/s10064-013-0487-2, 2013a.
Jørgensen, F., Sandersen, P. B. E., Høyer, A.-S., Pallesen, T. M., Foged, N., He, X., and Sonnenborg, T. O.: A 3-D geological model from Jutland, Denmark, Combining modeling techniques to address variations in data density, data type, and geology, The Geological Society of America, 125th Anniversary Annual Meeting, Denver, Colorado, USA, 2013b.
Møller, I., Verner, H., Søndergaard, V. H., Flemming, J., Auken, E., and Christiansen, A. V.: Integrated management and utilization of hydrogeophysical data on a national scale, Near Surf. Geophys., 7, 647–659, 2009.
Paasche, H.,Tronicke, J., Holliger, K., Green, A. G., and Maurer, H.: Integration of diverse physical-property models: Subsurface zonation and petrophysical parameter estimation based on fuzzy c means cluster analyses, Geophysics, 71, H33–H44, 2006.
Pebesma, E. J. and C. G. Wesseling: Gstat: A Program for geostatistical Modelling, Prediction and Simultation, Comput. Geosci., 24, 17–31, 1998.
Raiber, M., White, P. A., Daughney, C. J., Tschritter, C., Davidson, P., and Bainbridge, S. E.: Three-dimensional geological modelling and multivariate statistical analysis of water chemistry data to analyse and visualise aquifer structure and groundwater composition in the Wairau Plain, Marlborough District, New Zealand, J. Hydrol., 48, 436–437, 2012.
Rasmussen, E. S., Dybkjær, K., and Piasecki, S.: Lithostratigraphy of the upper Oligocene – Miocene succession of Denmark, Geol. Surv. Den. Greenl., 22, 1–92, 2010.
Refsgaard, A., Auken, E., Bamberg, C. A., Christensen, B. S. B., Clausen, T., Dalgaard, E., Effersø, F., Ernstsen, V., Gertz, F., Hansen, A. L., He, X., Jacobsen,B. H., Jensen, K. H., Jørgensen, F., Jørgensen, L. F., Koch, J., Nilsson, B., Petersen, C., DeSchepper, G., Schamper, C., Sørensen, K. I., Therrien, R., Thirup, C., and Viezzoli, A.: Nitrate reduction in geologically heterogeneous catchments – A framework for assessing the scale of predictive capability of hydrological models, ScienceDirect, 468–469, 1278–1288, 2014.
Revil, A. and Glover, P. W. J.: Nature of surface electrical conductivity in natural sands, sandstones, and clays, Geophys. Res. Lett., 25, 691–694, 1998.
Sandersen, P., Jørgensen, F., Larsen, N. K., Westergaard, J. H., and Auken, E.: Rapid tunnel-valley formation beneath the receding Late Weichselian ice sheet in Vendsyssel, Denmark, Boreas, 38, 834–851, https://doi.org/10.1111/j.1502-3885.2009.00105.x, 2009.
Schamper, C., Auken, E., and Sørensen, K. I.: Coil response inversion for very early time modelling of helicopter-borne time-domain electromagnetic data and mapping of near-surface geological layers, Geophys. Prospect., 62, 658–674, https://doi.org/10.1111/1365-2478.12104, 2014a.
Schamper, C., Jørgensen, F., Auken, E., and Effersø, F.: Assessment of near-surface mapping capabilities by airborne transient electromagnetic data – An extensive comparison to conventional borehole data, Geophysics, 79, B187–B199, https://doi.org/10.1190/geo2013-0256.1, 2014b.
Seifert, D., Sonnenborg, T. O., Refsgaard, J. C., Højberg, A. L., and Troldborg, L.: Assessment of hydrological model predictive ability given multiple conceptual geological models: Water Resour. Res., 48, W06503, https://doi.org/10.1029/2011WR011149, 2012.
Sen, P. N.: Electrochemical origin of conduction in shaly formations: Society of Petroleum Engineers, Presented at 62nd Annual Technical Conference and Exhibition, 1987.
Slater, L.: Near surface electrical characterization of hydraulic conductivity: From petrophysical properties to aquifer geometries – A review, Surv. Geophys., 28, 169–197, 2007.
Stafleu, J., Maljers, D., Gunnink, J. L., Menkovic, A., and Busschers, F. S.: 3-D modelling of the shallow subsurface of Zeeland, the Netherlands: Geologie en Mijnbouw/Netherlands, J. Geosci., 90, 293–310, 2011.
Strebelle, S.: Conditional simulation of complex geological structures using multiple-point statistics, Math. Geol., 34, 1–21, 2002.
Triantafilis, J. and Buchanan, S. M.: Identifying common near-surface and subsurface stratigraphic units using EM34 signal data and fuzzy k means analysis in the Darling River valley, Aust. J. Earth Sci., 56, 535–558, 2009.
Turner, A.: Challenges and trends for geological modelling and visualisation, B. Eng. Geol. Environ., 65, 109–127, 2006.
Viezzoli, A., Christiansen, A. V., Auken, E., and Sørensen, K. I.: Quasi-3-D modeling of airborne TEM data by Spatially Constrained Inversion, Geophysics, 73, F105–F113, 2008.
Waxman, M. H. and Smits, L. J. M.: Electrical Conductivities in Oil-Bearing Shaly Sands, Society of Petroleum Engineers Journal, 8, 107–122, 1968.
Wisén, R., Auken, E., and Dahlin, T.: Combination of 1-D laterally constrained inversion and 2-D smooth inversion of resistivity data with a priori data from boreholes, Near Surf. Geophys., 3, 71–79, 2005.
Wu, J.: Advances in k means Clustering: A Data Mining Thinking, Springer, 2012.