scholarly journals An alternative 3D inversion method for magnetic anomalies with depth resolution

2009 ◽  
Vol 49 (4-5) ◽  
Author(s):  
A. Pignatelli ◽  
I. Nicolosi ◽  
M. Chiappini
Keyword(s):  
Depth Resolution ◽  
Magnetic Anomalies ◽  
Inversion Method ◽  
3D Inversion

scholarly journals 3D inversion and resolution analysis of land-based CSEM data from the Ketzin CO2 storage formation

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. E101-E114 ◽  
Author(s):  
Alexander V. Grayver ◽  
Rita Streich ◽  
Oliver Ritter
Keyword(s):  
Electric Field ◽  
Co2 Storage ◽  
Model Space ◽  
Depth Resolution ◽  
Data Uncertainty ◽  
Model Assessment ◽  
3D Inversion ◽  
Inversion Domain ◽  
Resolution Analysis ◽  
Robust Processing

We evaluated 3D inversion of land controlled-source electromagnetic (CSEM) data collected across the Ketzin [Formula: see text] storage formation. A newly developed, parallel and distributed 3D inversion code, which is based on a direct forward solver, has been used. This inversion scheme allowed us to calculate the Jacobian matrix explicitly within a reasonable time and use it to calculate regularization parameters, inspect survey coverage, and carry out resolution analysis. After demonstrating that the magnetic field components are sensitive to conductors only, whereas the electric field components are sensitive to all features of interest, we continued to work with electric field data only. Estimates of data uncertainty obtained from robust processing were used for automated data preselection and weighting during inversion. We tested different regularization techniques and a range of starting models to explore the model space and assess the influence of regularization on the inversion images. We further demonstrated an approach for handling numerical singularities due to sources located inside the inversion domain. We estimated survey coverage, horizontal and vertical resolution, and depth penetration using cumulative sensitivity, point spread functions, and depth-resolution plots. Based on data fit analysis, we determined a preferred subsurface conductivity model, which we compared to an independent regional structural geologic model, and we provided an interpretation for the structures resolved. The inversion approach we used provides robust results in good agreement with known geology, offers new possibilities for model assessment, and should be transferable to other CSEM data sets.

3D Inversion of Potential Fields with Depth Resolution

2001 ◽  
Author(s):  
V. Paoletti ◽  
M. Fedi ◽  
P.C. Hansen ◽  
A. Rapolla
Keyword(s):  
Depth Resolution ◽  
Potential Fields ◽  
3D Inversion

A Position-First 3D Inversion Method for Tomosar

2021 ◽  
Author(s):  
Ruizhe Shi ◽  
Zekun Jiao ◽  
Xiaolan Qiu ◽  
Chibiao Ding
Keyword(s):  
Inversion Method ◽  
3D Inversion

Uncertainties in breakup markers along the Iberian Newfoundland margin: The need for a new North Atlantic plate model

2020 ◽  
Author(s):  
Annabel Causer ◽  
Lucía Pérez-Díaz ◽  
Graeme Eagles ◽  
Jürgen Adam
Keyword(s):  
North Atlantic ◽  
Magnetic Anomalies ◽  
Oceanic Lithosphere ◽  
Seafloor Spreading ◽  
Inversion Method ◽  
Seismic Profiles ◽  
Potential Field Data ◽  
Rifted Margins ◽  
Basement Faults ◽  
Break Up

<p>The Iberian-Newfoundland conjugate margins are one of the most extensively studied non-volcanic rifted margins in the world. In recent years, researchers have focused their efforts at better understanding the earliest stages of continental rifting, often relying heavily on the identification of so-called “break-up features” imaged in seismic profiles or interpreted from potential field data. Along the Iberian-Newfoundland margins, widely used break-up markers include interpretations of old magnetic anomalies from the M-Series, as well as the J-anomaly, believed to mark the occurrence and spatial extent of first oceanic lithosphere. However, uncertainties in the location and interpretation of these features have led to discrepancies between modelled depictions of the palaeopositions of Iberia and Newfoundland during the early Cretaceous as well as the timing of first seafloor spreading between the two. </p><p>Using new seismic data from the Southern Newfoundland Basin (SNB) we are able to illustrate the unsuitability of “break-up” features along the Iberian – Newfoundland Margin for plate kinematic reconstructions. Our data shows that basement associated with the younger M-Series magnetic anomalies is comprised of exhumed mantle and magmatic additions, and most likely represents transitional domains and not true oceanic lithosphere. Magmatic activity in the SNB as early as M4 times (128 Ma), and the presence of SDR packages onlapping onto basement faults suggest that, at this time, plate divergence was still being accommodated by tectonic faulting. Therefore, young M-series anomalies (including the J-anomaly) are not suitable basis on which to reconstruct plate positions during the early stages of continental separation.</p><p>We instead follow an alternative modelling approach, not reliant on the identification of extended continental margin features, to robustly constrain North Atlantic tectonics pre-M0 (~121 Ma) times. We do this by using seafloor spreading data and a statistically robust inversion method as the basis for a number of purpose built two-plate models for Africa, Iberia, Eurasia, Greenland and North America, with quantified uncertainties. Together, these models will provide an invaluable framework within to study the evolution of the extended continental margins immediately prior to and during continental separation.</p><p> </p><p> </p><p> </p><p> </p><p> </p>

Integrating multiscale parameters information into 3D stochastic magnetic anomaly inversion

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. D85-D93 ◽  
Author(s):  
Pejman Shamsipour ◽  
Denis Marcotte ◽  
Michel Chouteau
Keyword(s):  
Magnetic Anomaly ◽  
Solution Space ◽  
Depth Resolution ◽  
Multiple Scale ◽  
Massive Sulfide ◽  
Inversion Method ◽  
Borehole Data ◽  
Scale Parameters ◽  
Geostatistical Approach ◽  
Surface Data

We present a 3D stochastic inversion method based on the geostatistical approach of cokriging for inversion of magnetic anomaly data on multiple scale parameters using borehole and surface data to limit the resulting solution space. Recovering susceptibilities in 3D magnetic anomaly inversion requires integration of many different data. These data mainly come from different sources with different volume supports (point and block support). The presented algorithm has the capability of inverting data on multiple supports using downscaling and upscaling. Borehole susceptibilities (point support) are up-scaled to block susceptibilities where some of them are selected as constraints. The block constraints are used in magnetic anomaly inversion and, finally, the inverted susceptibilities are down-scaled to small prisms. Two modes of application are presented: estimation and simulation. The method is first applied to a synthetic stochastic model. The results of downscaling and upscaling show the ability of the method to invert surface and borehole data simultaneously on multiple scale parameters. The results also clearly show the significant role of borehole data in improving depth resolution. Finally, a case study using susceptibility measurements collected on outcrops and on numerous borehole cores at the Perseverance mine (Quebec, Canada) is presented. The information from the recovered 3D model are useful in analyzing the geology of massive sulfide for the domain under study. It also shows that the addition of constraints at different scales helps in delineating bodies, which would have been missed by only using the magnetic anomaly data.

scholarly journals Analisis Sebaran Mineral Logam Pada Sedimentasi Batuan Di Daerah Kertajadi, Cidaun, Kabupaten Cianjur, Jawa Barat Menggunakan Metoda Geomagnet

Wahana Fisika ◽  
2017 ◽  
Vol 2 (1) ◽  
pp. 37
Author(s):  
Rajab Basuki ◽  
Nanang Dwi Ardi ◽  
Mimin Iryanti
Keyword(s):  
Magnetic Anomaly ◽  
Mineral Exploration ◽  
Ferrous Metal ◽  
Magnetic Anomalies ◽  
Coastal Areas ◽  
Inversion Method ◽  
Quantitative Interpretation ◽  
West Java ◽  
Value Range ◽  
The Difference

Cidaun merupakan salah satu daerah pesisir pantai selatan yang terletak pada Kabupaten Cinajur Provinsi Jawa Barat. Salah satu kelebihan dari daerah pesisir pantai selatan Pulau Jawa adalah terdapat banyaknya mineral logam penghasil besi yang tersebar luas di sepanjang pesisir pantai. Oleh karena itu dilakukanlah eksplorasi untuk memetakan sebaran mineral logam yang ada di daerah Cidaun. Dalam melakukan eksplorasi mineral logam dibutuhkan suatu metode yang paling efektif yaitu eksplorasi geofisika dengan menggunakan metode geomagnet. Proses pengolahan data pada metode geomagnet dilakukan dengan menghitung nilai anomali magnetik dari medan magnetik total yang telah dilakukan koreksi terhadap koreksi harian dan koreksi IGRF. Kemudian dengan metode inversi data yang telah didapat dijadikan sebuah model. Selain itu dilakukan juga interpretasi kualitatif dan interpretasi kuantitatif. Interperetasi kualitatif dilakukan pada data yang telah dimodelkan menggunakan software surfer 11, apabila data tersebut terdapat anomali magnetik bernilai sangat tinggi yang berdekatan dengan nilai anomali magnetik bernilai rendah atau perubahan nilai anomali terjadi secara signifikan kemudian dilakukan proses interpretasi secara kuantitatif. Interpretasi kuantitatif pada penelitian ini dengan dilakukan deliniasi berupa proses sayatan pada perbedaan nilai anomali magnetik yang terjadi perubahan secara signifikan. Tahap selanjutnya data dari proses sayatan tersebut kemudian dilakukanlah pemodelan menggunakan software mag2dc untuk mengetahui sebaran mineral logam dapa daerah tersebut. Berdasarkan data yang telah diolah pada daerah Kertajadi, Cidaun, Kabupaten Cianjur, Jawa Barat dengan koordinat 698283 easting - 757162 easting dan 9180169 northing - 9171050 northing memiliki rentang nilai anomali magnetik -5 nT – 145 nT. Sedangkan nilai anomali magnetik pada daerah yang telah dilakukan proses sayatan memiliki rentang nilai 84.18 nT - 119.69 nT dengan nilai susptibilitas -0.041000 – 0.050001. Dari rentang nilai suseptibilitas tersebut diduga sebaran mineral yang yang memiliki nilai suseptibilitas positif merupakan bijih besi sedangkan yang bernilai negatif merupakan lempung dan endapan pasir. Dari hasil dari penelitian ini diharapkan data tersebut dapat dijadikan informasi dan referensi bagi masyarakat, peneliti lain dan pengusaha tambang dalam eksplorasi mineral logam.Cidaun is one of the coastal areas of the southern coast located in the district of West Java province Cinajur. One of the advantages of the southern coastal areas of Java is that there are many ferrous metal mineral producer widespread along the coast. Therefore, the exploration was undertaken to map the distribution of metallic minerals in the area Cidaun. In conducting metal mineral exploration required a most effective method is a geophysical exploration using geomagnetic methods. Data processing on geomagnetic method is done by calculating the value of the magnetic anomalies of the total magnetic field has a daily correction of correction and correction IGRF. Then, with the inversion method of data has been obtained serve as a model. The researcher also interpretation of qualitative and quantitative interpretation. Qualitative Interperetasi performed on the data that has been modeled using software surfer 11, when the inputs are very high-value magnetic anomalies adjacent to the value of the magnetic anomalies of low value or change in value of the anomaly occurred significantly later performed quantitative interpretation process. Quantitative interpretation in this study conducted a process of delineation of the incision on the difference in magnetic anomaly change significantly. The next stage of the data are then perform the incision process modeling using software mag2dc to determine the distribution of metallic minerals onshore areas. Based on the data that has been processed in the region Kertajadi, Cidaun, Cianjur, West Java coordinate 698283 easting - 757162 easting and 9180169 northing - 917105 northing and has a value range of magnetic anomaly -5 nT - 145 nT. While the value of magnetic anomalies in the area that has been carried out the process of incisions have a range of values 84.18 nT - 119.69 nT with susptibilitas value -0.041000 - 0.050001. Of the value range susceptibility is suspected distribution of minerals that have a positive susceptibility value is the iron ore which is negative while the clay and sand deposits. From the results of this study are expected data can be made of information and reference for the community, other researchers and mining company in mineral exploration.

scholarly journals Inversion Technique of Physical Parameters Based on Regularization Extension Depth Constraint

2019 ◽  
Vol 23 (4) ◽  
pp. 331-338
Author(s):  
Yang Wang ◽  
Jun Li ◽  
Xuben Wang ◽  
Xingxiang Jian
Keyword(s):  
Physical Property ◽  
Magnetic Anomalies ◽  
Downward Continuation ◽  
Resolving Power ◽  
Depth Of Field ◽  
Inversion Method ◽  
Physical Parameters ◽  
Field Source ◽  
Gravity And Magnetic ◽  
Downward Continuation Of Gravity

Through the regularization downward continuation of gravity and magnetic anomalies, the depth of the field source can be solved. However, due to the Gibbs effect, the horizontal resolving power of the field source is poor. In view of this, based on the depth of field source established by regularization downward continuation, this paper proposes a physical property parameter inversion method based on iterative continuation and anomaly separation, which can effectively improve the inversion accuracy of superimposed anomaly physical parameters, and provide a new idea for solving the physical parameters of superposition gravity and magnetic anomalies.

3D inversion of airborne gravity gradiometry data for the Budgell Harbour Stock, Newfoundland: A case history using a probabilistic approach

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. B269-B284 ◽  
Author(s):  
Meixia Geng ◽  
J. Kim Welford ◽  
Colin G. Farquharson ◽  
Alexander L. Peace
Keyword(s):  
Joint Inversion ◽  
Probabilistic Approach ◽  
Stable Solution ◽  
Airborne Gravity ◽  
Inversion Method ◽  
Gravity Gradiometry ◽  
3D Inversion ◽  
Long Wavelength ◽  
Text Model ◽  
Airborne Gravity Gradiometry

We have studied the Mesozoic Budgell Harbour Stock, a gabbroic intrusion in north-central Newfoundland, Canada, using 3D inversion of airborne gravity gradiometry data based on a probabilistic inversion method. Significantly, differences were observed between the results when inverting the single [Formula: see text] component and when inverting the 5C combination. We also found that the [Formula: see text] model failed to reproduce the long-wavelength signals from other components, whereas the model recovered from five components accommodated all of the signals from all of the components. To estimate the influence of long-wavelength signals from targets other than the intrusion, such as deeper bodies or large-scale terrain variations, inversion tests are performed on a synthetic model. The inversion results for the synthetic example indicate that the joint inversion of five components is more sensitive to long-wavelength signals, which can generate spurious structures to fit all of the signals from the five components. In contrast, the [Formula: see text] model is less affected by the long-wavelength signals and thus tends to produce a stable solution, despite failing to incorporate all of the long-wavelength signals from the tensor data. We found that gravity gradiometry data could be used to delineate the intrusion within this study area, which is also consistent with the susceptibility model recovered from inversion of aeromagnetic data and with results from a previous geophysical study. Moreover, the differences between the [Formula: see text] model and the 5C model may reflect the long-wavelength signals in the gravity gradiometry data.

scholarly journals Joint interpretation of gravity and magnetic data in the Kolárovo anomaly region by separation of sources and the inversion method of local corrections

2014 ◽  
Vol 65 (2) ◽  
pp. 163-174 ◽  
Author(s):  
Ilya Prutkin ◽  
Peter Vajda ◽  
Miroslav Bielik ◽  
Vladimír Bezák ◽  
Robert Tenzer
Keyword(s):  
Lower Crust ◽  
Magnetic Anomalies ◽  
Magnetic Data ◽  
Inversion Method ◽  
Upper Crust ◽  
Linear Inversion ◽  
Danube Basin ◽  
Potential Field Data ◽  
Gravity And Magnetic ◽  
Admissible Solutions

Abstract We present a new interpretation of the Kolárovo gravity and magnetic anomalies in the Danube Basin based on an inversion methodology that comprises the following numerical procedures: removal of regional trend, depth-wise separation of signal of sources, approximation of multiple sources by 3D line segments, non-linear inversion based on local corrections resulting in found sources specified as 3D star-convex homogenous bodies and/or 3D contrasting structural contact surfaces. This inversion methodology produces several admissible solutions from the viewpoint of potential field data. These solutions are then studied in terms of their feasibility taking into consideration all available tectono-geological information. By this inversion methodology we interpret here the Kolárovo gravity and magnetic anomalies jointly. Our inversion generates several admissible solutions in terms of the shape, size and location of a basic intrusion into the upper crust, or the shape and depth of the upper/lower crust interface, or an intrusion into the crystalline crust above a rise of the mafic lower crust. Our intrusive bodies lie at depths between 5 and 12 km. Our lower crust elevation rises to 12 km with and 8 km without the accompanying intrusion into the upper crust, respectively. Our solutions are in reasonable agreement with various previous interpretations of the Kolárovo anomaly, but yield a better and more realistic geometrical resolution for the source bodies. These admissible solutions are next discussed in the context of geological and tectonic considerations, mainly in relation to the fault systems.

Application of 3D Apparent Physical Properties Inversion Method in an Iron Mine Area

2013 ◽  
Vol 734-737 ◽  
pp. 37-40
Author(s):  
Hai Xia Li ◽  
Hai Long Yu ◽  
Ping Chuan Zhang
Keyword(s):  
Physical Properties ◽  
Magnetic Data ◽  
Inversion Method ◽  
Algebraic Equations ◽  
Large Area ◽  
3D Inversion ◽  
Large Computer ◽  
Mine Area ◽  
Linear Algebraic Equations ◽  
Iron Mine

A rapid method for 3D physical properties inversion based on separation and continuation of potential field are introduced in this paper. The inversion technique characterized by faster computing speed, it does not need to divide the underground field sources region into many rectangular blocks in one time and does not need to solve linear algebraic equations as well. So, this technique can overcome the requirement of large computer memory, unstable solution and computation time bottleneck which hinders the application of 3D inversion to practice. The method is used to apparent magnetic susceptibility inversion of magnetic anomaly in a iron mine area, the inversion results show that the method has good accuracy, and the advantages of strong stability and a high computation speed, and is suitable for 3D inversion of magnetic data in large area.

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