HR: 0800h
AN: GP31A-03    [Abstracts]
TI: Source location estimation from noisy magnetic data using Euler's homogeneity equation
AU: * Longo, L M
EM: lmlongoc@repsolypf.com
AF: REPSOL YPF Argentina, Talero 360, Neuquen, Nqn 8300, Argentina
AU: Ravazzoli, C L
EM: claudia@fcaglp.fcaglp.unlp.edu.ar
AF: CONICET and Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La PLata, Paseo del Bosque S/N, La Plata, Bue 1900, Argentina
AB: The development of automated techniques for the determination of the equivalent source location and characteristics from total field magnetic anomalies is an important task in potential field geophysics. This is especially convenient when large data sets are available, such as those measured in aeromagnetic surveys. In the context of hydrocarbon exploration, magnetic depth estimation is useful to know the thickness of the sedimentary section, since most sedimentary rocks have very low magnetizations. For mineral exploration these tools are applicable to the location of ore bodies containing magnetic minerals which motivated the interest of many authors in this field. In this work we focus our attention in the well known Euler's deconvolution procedure, in which the homogeneity properties of the magnetic fields associated to simple concentrated sources are used to estimate their horizontal position and depth. Although this approach has the advantage of not assuming a priori any particular geologic model, it requires the numerical computation of derivatives of the magnetic anomalies. These operations can be efficiently performed in the spatial wavenumber domain taking into account some general properties of the Fourier transforms of the scalar magnetic potentials. We present numerical examples to analyze the applicability of the method for the estimation of the source parameters associated to synthetic two-dimensional anomalies (i.e. profile data) for different models and geomagnetic inclinations, analyzing the convenience of using pole-reduced anomaly data. A parametric analysis of the solutions in the presence of random noise is also performed. The validity of the depth of the equivalent source as an indicator of the true depth to the top of the magnetic structures is also discussed, aiming at practical applications with real aeromagnetic data measured over the Argentine Atlantic ocean.
DE: 0903 Computational methods: potential fields (1214)
DE: 0925 Magnetic and electrical methods (5109)
DE: 3299 General or miscellaneous
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly