Constrained Two-Dimensional Inversion of Gravity Data
DOI:
https://doi.org/10.5614/j.math.fund.sci.2014.46.1.1Keywords:
density estimation, linear inversion, potential field, prior informationAbstract
The non-uniqueness in the solution of gravity inversion poses a major problem in the interpretation of gravity data. To overcome this ambiguity, "a priori" information is introduced by minimizing a functional that describes the geometrical or physical properties of the solution. This paper presents a 2D gravity inversion technique incorporating axes of anomalous mass concentration as constraints. The inverse problem is formulated as a minimization of the moment of inertia of the causative body with respect to the axes of the mass concentration. The proposed method is particularly applicable to homogeneous, linear mass distributions, such as mineralization along faults and intruded sills or dikes. Inversions of synthetic and field data illustrate the versatility of the implemented algorithm.References
Caratori-Tontini, F., Cocchi, L. & Carmisciano, C., Potential-Field Inversion for a Layer with Uneven Thickness: the Tyrrhenian Sea Density Model, Physics of the Earth and Planetary Interiors, 166(1), pp. 105-111, 2008.
Tadjou, J.M., Nouayou, R., Kamguia, J., Kande, H.L. & Manguelle-Dicou, E. Gravity Analysis of the Boundary Between the Congo Craton and the Pan-African Belt of Cameroon, Austrian Journal of Earth Sciences, 102(1), pp. 71-79, 2009.
Nagihara, S. & Hall, S.A., Three-Dimensional Gravity Inversion Using Simulated Annealing: Constraints on the Diapiric Roots of Allochthonous Salt Structures, Geophysics, 66(5), pp. 1438-1449, 2001.
Allen, T.I., Cooper, S.A. & Cull, J.P., High Definition Gravity Surveys and Density Modelling for Kimberlite Exploration, Exploration Geophysics, 32(2), pp. 89-94, 2001.
Peacock, R.J., Cavity Detection? An Engineering Application for Gravity, Exploration Geophysics, 23(4), pp. 567-570, 1992.
Bear, G.W., Al-Shukri, H.J. & Rudman, A.J., Linear Inversion of Gravity Data for 3D Density Distributions, Geophysics, 60(5), pp. 1354-1364, 1995.
Hinze, W.J., von Frese, R.R.B. & Saad, A.H., Gravity and Magnetic Exploration: Principles, Practices, and Applications, Cambridge University Press, Cambridge, 2013.
Grandis, H., Introduction to Geophysical Inversion (Text in Indonesian), Indonesian Association of Geophysicists (HAGI), Jakarta, 2009.
Menke, W., Geophysical Data Analysis: Discrete Inverse Theory, 3rd ed., Academic Press, New York, 2012.
Blakely, R.J., Potential Theory in Gravity and Magnetic Applications, Cambridge University Press, Cambridge, 1995.
Guillen, A. & Menichetti, V., Gravity and Magnetic Inversion with Minimization of a Specific Functional, Geophysics, 49(8), pp. 1354-1360, 1984.
Barbosa, V.C.F. & Silva, J.B.C., Generalized Compact Gravity Inversion, Geophysics, 59(1), pp. 57-68, 1994.
Silva, J.B.C. & Barbosa, V.C.F., Interactive Gravity Inversion, Geophysics, 71(1), pp. J1-J9, 2006.
Mendonca, C.A. & Silva, J.B.C., The Equivalent Data Concept Applied to the Interpolation of Potential Field Data, Geophysics, 59(5), pp. 722-732, 1994.
Mendonca, C.A. & Silva, J.B.C., Interpolation of Potential Field Data by Equivalent Layer and Minimum Curvature: A Comparative Analysis, Geophysics, 60(2), pp. 399-407, 1995.
Press, W.H., Flannery, B.P., Teukolsky, S.A. & Vetterling, W.T., Numerical Recipes: The Art of Scientific Computing, 2nd ed., Cambridge University Press, Cambridge, 1997.
Grandis, H., Equivalent-Source from 3D Inversion Modeling for Magnetic Data Transformation, International Journal of Geosciences, 4(7), pp. 1024-1030, 2013.
Li, Y.G. & Oldenburg, D.W., 3-D Inversion of Gravity Data, Geophysics, 63(1), pp. 109-119, 1998.
Yudistira, T. & Grandis, H., Inversion of 3D Magnetic Data, Proceedings of 26th Annual Convention of Indonesian Association of Geophysicists (HAGI), 2001.
