Constrained Joint Inversion of Gravity and Seismic Data Using the Simulated Annealing Algorithm

Self Cite

How to get rapid and stable inversion results and clear geological interfaces is a focus problem in current Magnetotelluric (MT) inversion. With the purpose to represent clear boundary with resistivity discontinuity, the paper integrates the ideas of OCCAM inversion and sharp boundary inversion (SBI) to construct a new objective function for inversion by using the minimum gradient support functional and conjugate gradient inversion method to solve the optimal minimum. So the 2-D MT inversion method based on OCCAM and SBI is fulfilled. Through the model tests and comparisons with the related published inversion results, this method is proved accurate in determining sharp electrical interfaces based on the smoothest and stable models. It is also applied to process the field observed MT data in the regions of Guangdong Xuwen, the results indicate this method's effect and feasibility.

Section: Field Data Applicationmentioning

confidence: 99%

Smoothest Model and Sharp Boundary Based Two‐Dimensional Magnetotelluric Inversion

Zhang¹,

Yu²,

Wang³

et al. 2009

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“…The author ever used the improved VFSA of Yang [19] and Chen et al [17,20] to conduct a joint inversion of magnetotelluric and seismic data and also the integrated inversion of gravity & magnetic data [21,22] . He also carried out a constrained joint inversion of gravity and seismic data using VFSA algorithm [23] , and quite good effects were obtained. Therefore, the gravity anomaly inversion including the synthetic model test and field observed data using this self-developed improved VFSA is introduced in this paper.…”

Section: The Improved Very Fast Simulated Annealing Algorithmmentioning

confidence: 99%

An Inversion of Gravity Anomalies by Using a 2.5 Dimensional Rectangle Gridded Model and the Simulated Annealing Algorithm

Yu¹,

Wang²,

Wu³

2007

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In accordance with the present state of gravity anomaly inversion, we use the 2.5 dimensional model construction method to divide the underground density structure into rectangle gridded units to simulate density models with arbitrary interfaces or bodies, then perform gravity forward modeling. This model construction is flexible and adaptable especially for the complicated geological models with horizontal varying densities usually appearing in practical situations. We employ the improved very fast simulated annealing algorithm (VFSA), which has obvious advantage of finding the global optimal solution in inverse problems to perform gravity anomaly inversion. Only the value of each rectangle unit needs to be inversed, the interfaces or shapes and the density distributions can be simultaneously determined during gravity anomaly inversion. Through the complicated model test, this approach is proved effective and practicable. The application in the lower Yangtze area of Jiangsu shows that this inversion approach could increase the accuracy of inversion under the constrained conditions of prior seismic data, the objective strata of Devonian‐Silurian and related geological problems could also be solved efficiently.

“…We have realized a constrained synchronous joint inversion of gravity and seismic data using improved simulated annealing algorithm [5] on the basis of analyses of present situations in gravity and seismic joint inversion, the effects and features of this method were represented by model test with uncommon density and velocity interfaces and practical application. Among them, gravity forward modeling was fulfilled by using a 2.5 dimensional rectangle gridded model [5,6] , the seismic travel time was computed by shooting method of raytracing [5,7] . The advantages of adopting travel time in joint inversion lie in that travel time depends mainly on the velocity structure and without close relations with exciting-receiving conditions and instrument properties, so may have high S/N ratio.…”

Section: Introductionmentioning

confidence: 99%

“…The advantages of adopting travel time in joint inversion lie in that travel time depends mainly on the velocity structure and without close relations with exciting-receiving conditions and instrument properties, so may have high S/N ratio. There are many methods to compute travel time, the shooting method uses ray-tracing equation to compute travel times and adjusts the shooting angle and ray density, the travel time is found by interpolating between the two rays closest to the receiver [5] . However, rays tracing may not be accurately determined when using shooting method in gridded media especially in the situations of low velocity stratum or large velocity variations [8] .…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the realized synchronous joint inversion techniques of magnetotelluric-seismic and gravityseismic data [5,7] , required the numbers of velocity strata and the value of velocity in each stratum should be identical without variation in the overall velocity model. Therefore, when facing the situations of complex structure with interface discontinuity and large horizontal variation of velocity, this kind of simple velocity model used by these joint inversion techniques could not meet the needs of solving practical geological problems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Joint Inversion of Gravity and Seismic Data Based on Common Gridded Model with Random Density and Velocity Distributions

Dai

Wang

et al. 2008

Self Cite

In view of the problems existing in joint inversion of gravity & seismic data and the published research results, we study a model construction method based on common gridded model with random density and velocity distributions to meet the needs of joint inversion and the complicated model with large density and velocity variations. 2.5 dimensional gravity forward modeling is fulfilled in accordance with this gridded model. By improving the ray-tracing method in 2 dimensional seismic travel-time computing to suit the gridded media with random velocity distribution, we realize the synchronous joint inversion of gravity & seismic data based on this kind of common gridded model in accordance with the improved very fast simulated annealing algorithm. The model test shows that the joint inversion could accurately determine the density and velocity structures of complicated model with uncommon interface and large variations of density and velocity. Moreover, joint inversion method is clearly superior to the single inversion of gravity data. The joint inversion of the observed data with a priori constraining information also gives good effects, which make it clear that this method is effective and practicable in improving inversion accuracy and reducing ambiguity.