Depth Estimation of Simple Causative Sources from Gravity Gradient Tensor Invariants and Vertical Component

Abstract

The gravity gradient tensor (GGT) is deduced from products of second-order derivatives of the gravitational potential. A new method based on the invariants of the GGT has been proposed in this research to interpret gravity data due to sphere, infinite horizontal cylinder and semi-infinite vertical cylinder. The method estimates the depth of these simple causative sources from the multiplication of the maximum of the gravity vertical component by the maximum value of the invariants I 1 to I 2 ratio. To show the reliability and correctness of the estimated depths on 3-D models, the method has been tested using theoretical data with and without random noise. In addition, I have applied the method to a field-data example in Texas, USA and the depth obtained by the present method is compared with those published in the literature.

Depth Estimation Method Based on the Ratio of Gravity and Full Tensor Gradient Invariant

“…Depth/km (NETTLETON 1976) 4.97 (MOHAN et al 1986) 4.63 (ABDELRAHMAN et al 1991) 4.65 (SHAW and AGARWAL 1997a) 4.13 (SALEM et al 2004) 5.12 (ESSA 2007) 4.18 (ORUÇ 2010) 4.12…”

Balanced gradient methods for the interpretation of gravity tensor gradient data

“…Some people (Beiki and Pedersen, 2010;Beiki et al, 2011;Wu et al, 2011) presented using the eigenvector of tensor gradient data to ascertain the locations of the geological bodies. Oruç (2010aOruç ( , 2010b combined the gravity tensor gradient invariants and vertical component to estimate the source depth. Oruç (2010aOruç ( , 2010b used the analytic signals of the magnetic tensor gradient and magnitude of vector components to compute the locations of the dipoles.…”

Güncel Optimizasyon Yöntemleri Kullanılarak Rezidüel Gravite Anomalilerinden Parametre Kestirimi

“…Gravite belirtilerinin değerlendirilmesi için çeşitli sayı-sal yöntemler kullanılmaktadır. En küçük kareler yaklaşımları (Gupta, 1983;Lines ve Treitel, 1984;Abdelrahman vd., 1991;Salem vd., 2003), Euler dekonvolüsyonu (Thompson, 1982;Reid vd., 1990), sinir ağları (Elawadi vd., 2001;Osman vd., 2007;Hajian, 2004), 3B analitik sinyal genliği (Roest vd., 1992), sürekli dalgacık dö-nüşümü (Chamoli vd., 2006), gravite tensörü-nün özvektör analizi (Beiki ve Pedersen, 2010), gravite gradyan tensörünün değişmezleri (Oruç, 2010), çoklu uyarlamalı nöro-bulanık çıkarım sistemleri (Hajian vd., 2011) bu yöntemlere ör-nek olarak gösterilebilir.…”