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Gravity inversion by the Multi‐HOmogeneity Depth Estimation method for investigating salt domes and complex sources
- Source :
- Geophysical Prospecting. 66:175-191
- Publication Year :
- 2018
- Publisher :
- Wiley, 2018.
-
Abstract
- We present a nonlinear method to invert potential fields data, based on inverting the scaling function (τ) of the potential fields, a quantity that is independent on the source property, that is the mass density in the gravity case or the magnetic susceptibility in the magnetic case. So, no a priori prescription of the density contrast is needed and the source model geometry is determined independently on it. We assume Talwani's formula and generalize the Multi-HOmogeneity Depth Estimation (MHODE) method to the case of the inhomogeneous field generated by a general 2D source. The scaling function is calculated at different altitudes along the lines defined by the extreme points of the potential fields and the inversion of the scaling function yields the coordinates of the vertices of a multiple source body. Once the geometry is estimated, the source density is automatically computed from a simple regression of the scaling function of the gravity data vs. that generated from the estimated source body with a unit-density. We solve the above nonlinear problem by the Very Fast Simulated Annealing algorithm. The best performance is obtained when some vertices are constrained by either reasonable bounds or exact knowledge. In the salt-dome case we assumed that the top of the body is known from seismic observations and we solved for the lateral and bottom parts of the body. We applied the technique on three synthetic cases of complex sources and on the gravity anomalies over the Mors salt-dome (Denmark) and the Godavari Basin (India). In all these cases the method performed very well in terms of both geometrical and source-property definition. This article is protected by copyright. All rights reserved
- Subjects :
- 010504 meteorology & atmospheric sciences
Gravity
Mathematical analysis
Inversion
010502 geochemistry & geophysics
01 natural sciences
Modelling
Gravity anomaly
Nonlinear system
Geophysics
Potential field
Geochemistry and Petrology
Simulated annealing
A priori and a posteriori
Extreme point
Density contrast
Geophysic
Scaling
0105 earth and related environmental sciences
Mathematics
Salt dome
Subjects
Details
- ISSN :
- 13652478 and 00168025
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- Geophysical Prospecting
- Accession number :
- edsair.doi.dedup.....fea600bfa92c44c621de62e8a0e5a75c