Automatic Interpretation of Magnetic Data Using Euler Deconvolution with Nonlinear Background

Abstract

The voluminous gravity and magnetic datasets demand automatic interpretation techniques like Naudy, Euler and Werner deconvolution. Of these techniques, the Euler deconvolution has become a popular choice because the method assumes no particular geological model. However, the conventional approach to solving Euler equation requires tentative values of the structural index preventing it from being fully automatic and assumes a constant background that can be easily violated if the singular points are close to each other. We propose a possible solution to these problems by simultaneously estimating the source location, depth and structural index assuming nonlinear background. The Euler equation is solved in a nonlinear fashion using optimization technique like conjugate gradient. This technique is applied to a published synthetic dataset where the magnetic anomalies were modeled for a complex assemblage of simple magnetic bodies. The results for close by singular points are superior to those obtained by assuming linear background. We also applied the technique to a magnetic dataset collected along the western continental margin of India. The results are in agreement with the regional magnetic interpretation and the bathymetric expressions.

Gravity and magnetic joint modeling of the Potiguar Rift Basin (NE Brazil): Basement control during Neocomian extension and deformation

“…The structural index can be determined by observing the clustering of solutions for different structural index values. For a particular feature, the correct structural index yields a tight cluster (Dewangan et al, 2007).…”

Evidences of a tectonic uplift and seismic hazard in south of the Pie de Palo Range, San Juan-Argentina

“…With this methodology, a variety of geological structures, such as faults, contacts, intrusive dykes, etc., can be identified and their depths estimated. However, the conventional approach to solving the Euler equation requires tentative values of the structural index, with results that are not fully automatic (Dewangan et al 2007).…”

Geophysical mapping of the inland extension of Deep Ocean Fault zones, south-western Nigeria

“…The second approach involved three-dimensional (3D) Euler Deconvolution method (Oruc and Selim, 2011;Dewangan et al, 2007;Reid et al, 1990;Marson and Klingele, 1993;Thompson, 1982) carried out to determine the shape and depth to magnetic anomaly sources, using both the 'Standard Euler' and 'Located Euler' Deconvolution approaches in order to arrive at the best results. Locations of peak-like structures were based on the Blakely (1996) method; using the highest sensitivity level to find all ridge peaks in the analytic signal map of the aeromagnetic data as described by Roest et al (1992).…”