Simultaneous inversion modeling of gravity and aeromagnetic data applied to a geothermal study in Utah

Geophysics ◽  
1984 ◽  
Vol 49 (8) ◽  
pp. 1327-1337 ◽  
Author(s):  
Laura F. Serpa ◽  
Kenneth L. Cook
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Hot Springs ◽  
Normal Faults ◽  
Geothermal Resource ◽  
Aeromagnetic Data ◽  
Potential Field Data ◽  
Simultaneous Inversion ◽  
Geothermal Potential ◽  
Deep Faults

Aeromagnetic and gravity surveys were conducted in the Black Rock Desert, Utah to assess the geothermal potential of the Meadow‐Hatton Known Geothermal Resource Area (KGRA). The presence of basalt flows less than 1000 yr old and a 400 000 yr old rhyolite dome suggested that a hot intrusive body, which should be detectable in both types of potential field data, may provide the heat source for hot springs in the study area. A simultaneous inversion computer program was developed as part of this study to model these potential field data. The resulting models indicate hydrothermal alteration about the hot springs extending to a depth of approximately 1 km. Normal faults above a low‐angle detachment appear to reach a depth of approximately 4 km and provide a path for the circulation of groundwater in the area. No evidence for a buried igneous body was found in the study area, and it is therefore concluded that the migration of fluids along the deep faults is sufficient to account for the water temperatures estimated for the KGRA.

Balancing images of potential-field data

Geophysics ◽  
2009 ◽  
Vol 74 (3) ◽  
pp. L17-L20 ◽  
Author(s):  
G. R. Cooper
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Large Range ◽  
Signal Amplitude ◽  
Analytic Signal ◽  
Aeromagnetic Data ◽  
Hilbert Transforms ◽  
Potential Field Data ◽  
Total Gradient ◽  
Data Source

Horizontal and vertical gradients, and filters based on them (such as the analytic signal), are used routinely to enhance detail in aeromagnetic data. However, when the data contain anomalies with a large range of amplitudes, the filtered data also will contain large and small amplitude responses, making the latter hard to see. This study suggests balancing the analytic signal amplitude (sometimes called the total gradient) by the use of its orthogonal Hilbert transforms, and shows that the balanced profile curvature can be an effective method of enhancing potential-field data. Source code is available from the author on request.

scholarly journals Implications of Tectonic Anomalies From Potential Field Data in Some Parts of Southeast Nigeria.

2021 ◽  
Author(s):  
STEPHEN EGUBA EKWOK ◽  
Anthony Effiong Akpan ◽  
Ogiji-Idaga Martins Achadu ◽  
Christian Atelwhobel Ulem
Keyword(s):  
Potential Field ◽  
High Frequency ◽  
Short Wavelength ◽  
Field Data ◽  
Low Frequency ◽  
Normal Faults ◽  
Tectonic Structures ◽  
Potential Field Data ◽  
Igneous Intrusions ◽  
Basin Topography

Abstract Tectonic structures controlling mineralization in some parts of Southeast Nigeria were evaluated using airborne potential field data. High and low frequency filters and depth determination tools were adopted to evaluate short and long wavelength anomalies, resolve the spatial spreading of igneous intrusions, depths to geologic sources and basin topography. The high frequency results exhibited high concentration of short wavelength anomalies in the Obudu Plateau and Ikom-Mamfe Rift. The underlying main tectonics of the area elucidated by the low frequency results caused the widespread occurrences of short wavelength geologic structures that are revealed by the high frequency maps. The study area is characterized by comparatively thin (~13.0 to <3000 m) sedimentation. The observed thin thickness is as a result of the massive Precambrian basement outcrops in some locations in the Obudu Plateau and the proliferation of igneous intrusions within this part of the Lower Benue Trough. The 2-D models showed the undulating nature of the underlying basin topography, the location of intrusions, domal structures and related normal faults. The locations and neighbourhood of intrusions and/or short wavelength structures are viable sites for lead-zinc-barite, brine and metallogenic minerals.

scholarly journals OpenMP Implementation of a Novel Potential-Field-Data Source-Growth-Based Inversion Approach for 3D Salt Imaging in Deepwater Gulf of Mexico

2020 ◽  
Vol 10 (14) ◽  
pp. 4798
Author(s):  
Naín Vera ◽  
Carlos Couder-Castañeda ◽  
Jorge Hernández ◽  
Alfredo Trujillo-Alcántara ◽  
Mauricio Orozco-del-Castillo ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Potential Field ◽  
Field Data ◽  
Three Dimensional ◽  
Synthetic Data ◽  
Complex Salt ◽  
Research Field ◽  
Inversion Method ◽  
Potential Field Data ◽  
Simultaneous Inversion

Potential-field-data imaging of complex geological features in deepwater salt-tectonic regions in the Gulf of Mexico remains an open active research field. There is still a lack of resolution in seismic imaging methods below and in the surroundings of allochthonous salt bodies. In this work, we present a novel three-dimensional potential-field-data simultaneous inversion method for imaging of salt features. This new approach incorporates a growth algorithm for source estimation, which progressively recovers geological structures by exploring a constrained parameter space; restrictions are posed from a priori geological knowledge of the study area. The algorithm is tested with synthetic data corresponding to a real complex salt-tectonic geological setting commonly found in exploration areas of deepwater Gulf of Mexico. Due to the huge amount of data involved in three-dimensional inversion of potential field data, the use of parallel computing techniques becomes mandatory. In this sense, to alleviate computational burden, an easy to implement parallelization strategy for the inversion scheme through OpenMP directives is presented. The methodology was applied to invert and integrate gravity, magnetic and full tensor gradient data of the study area.

Algorithm for error adjustment of potential field data along a survey network

Geophysics ◽  
1984 ◽  
Vol 49 (4) ◽  
pp. 467-469 ◽  
Author(s):  
P. K. Mittal
Keyword(s):  
Potential Field ◽  
Statistical Estimation ◽  
Field Data ◽  
Aeromagnetic Data ◽  
Rectangular Grid ◽  
Contour Map ◽  
Potential Field Data ◽  
Error Adjustment ◽  
Gravity And Magnetic ◽  
Instrumental Drift

Gravity and magnetic surveys on sea, land, or air invariably exhibit discrepancies at intersections of survey lines. These “misties” have to be removed before any meaningful contour map can be prepared. The misties are caused by many errors. Errors in location fixing, instrumental drift, diurnal magnetic variations, inaccuracies in Eötvös corrections because of errors in heading, and speed of ship or aircraft play a major role. Foster (1970) proposed a method for statistical estimation of the misties at line intersections with special reference to aeromagnetic data. The method can be extended to all gravity and magnetic surveys on land, sea, or air. However, it requires an approximately rectangular grid of survey lines. In case the network is irregular and there are lines in various directions crossing each other, Foster’s method would not be applicable.

Noniterative three‐dimensional inversion of magnetic data

Geophysics ◽  
1990 ◽  
Vol 55 (6) ◽  
pp. 782-785 ◽  
Author(s):  
A. M. Pustisek
Keyword(s):  
Inverse Problem ◽  
Potential Field ◽  
Field Data ◽  
Three Dimensional ◽  
Magnetic Data ◽  
Aeromagnetic Data ◽  
Nonlinear Inverse Problem ◽  
Potential Field Data

The interpretation of magnetic or aeromagnetic data often requires the inverse problem’s solution of the structure of the magnetization interface. This nonlinear inverse problem of mapping the basement topography from potential field data was first discussed by Peters (1949).

An improved approach for detecting the locations of the maxima in interpreting potential field data

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Luan Thanh Pham ◽  
Ozkan Kafadar ◽  
Erdinc Oksum ◽  
Ahmed M. Eldosouky
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Potential Field Data

Adaptive sampling of potential-field data: A direct approach to compressive inversion

Geophysics ◽  
2014 ◽  
Vol 79 (1) ◽  
pp. IM1-IM9 ◽  
Author(s):  
Nathan Leon Foks ◽  
Richard Krahenbuhl ◽  
Yaoguo Li
Keyword(s):  
Potential Field ◽  
Adaptive Sampling ◽  
Field Data ◽  
Computational Cost ◽  
Large Field ◽  
Magnetic Data ◽  
Data Sampling ◽  
Data Types ◽  
Data Set ◽  
Potential Field Data

Compressive inversion uses computational algorithms that decrease the time and storage needs of a traditional inverse problem. Most compression approaches focus on the model domain, and very few, other than traditional downsampling focus on the data domain for potential-field applications. To further the compression in the data domain, a direct and practical approach to the adaptive downsampling of potential-field data for large inversion problems has been developed. The approach is formulated to significantly reduce the quantity of data in relatively smooth or quiet regions of the data set, while preserving the signal anomalies that contain the relevant target information. Two major benefits arise from this form of compressive inversion. First, because the approach compresses the problem in the data domain, it can be applied immediately without the addition of, or modification to, existing inversion software. Second, as most industry software use some form of model or sensitivity compression, the addition of this adaptive data sampling creates a complete compressive inversion methodology whereby the reduction of computational cost is achieved simultaneously in the model and data domains. We applied the method to a synthetic magnetic data set and two large field magnetic data sets; however, the method is also applicable to other data types. Our results showed that the relevant model information is maintained after inversion despite using 1%–5% of the data.

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