Seismic attributes and gravity and magnetic transformations: The same mathematics under different names for different geophysical data sets

Author(s):  
Xiong Li
Author(s):  
Francesca Pace ◽  
Alessandro Santilano ◽  
Alberto Godio

AbstractThis paper reviews the application of the algorithm particle swarm optimization (PSO) to perform stochastic inverse modeling of geophysical data. The main features of PSO are summarized, and the most important contributions in several geophysical fields are analyzed. The aim is to indicate the fundamental steps of the evolution of PSO methodologies that have been adopted to model the Earth’s subsurface and then to undertake a critical evaluation of their benefits and limitations. Original works have been selected from the existing geophysical literature to illustrate successful PSO applied to the interpretation of electromagnetic (magnetotelluric and time-domain) data, gravimetric and magnetic data, self-potential, direct current and seismic data. These case studies are critically described and compared. In addition, joint optimization of multiple geophysical data sets by means of multi-objective PSO is presented to highlight the advantage of using a single solver that deploys Pareto optimality to handle different data sets without conflicting solutions. Finally, we propose best practices for the implementation of a customized algorithm from scratch to perform stochastic inverse modeling of any kind of geophysical data sets for the benefit of PSO practitioners or inexperienced researchers.


2021 ◽  
Author(s):  
Patricia MacQueen ◽  
Joachim Gottsmann ◽  
Matthew Pritchard ◽  
Nicola Young ◽  
Faustino Ticona J. ◽  
...  

Geophysics ◽  
2007 ◽  
Vol 72 (3) ◽  
pp. A29-A33 ◽  
Author(s):  
Sergey Fomel

Local seismic attributes measure seismic signal characteristics not instantaneously, at each signal point, and not globally, across a data window, but locally in the neighborhood of each point. I define local attributes with the help of regularized inversion and demonstrate their usefulness for measuring local frequencies of seismic signals and local similarity between different data sets. I use shaping regularization for controlling the locality and smoothness of local attributes. A multicomponent-image-registration example from a nine-component land survey illustrates practical applications of local attributes for measuring differences between registered images.


2021 ◽  
Author(s):  
Alexey Shklyaruk ◽  
Kirill Kuznetsov ◽  
David Arutyunyan ◽  
Ivan Lygin

<p>At the stage of small and medium-scale geological and geophysical studies, in addition to seismic exploration, methods of potential fields (gravimetry and magnetometry) are usually actively used. These methods, in contrast to the profile seismic observations, taking into account modern satellite and aviation technologies, provide a high-quality areal density and magnetic characteristics of the study area. The main tasks of modern gravimetry and magnetometry include the task of constructing areal models, contrasting in density and magnetization of surfaces. Among a large number of algorithmic solutions, the most effective are methods using an integrated approach, in which seismic data on the morphology of reflecting horizon is used as a reference.</p><p>Reconstruction of the structural surface morphology by geophysical data can be considered as the problem of finding the relationship between the input information (potential fields, geophysical data, and available a priori information) and the desired surface. To assess the dependence, it is proposed to use the reference plots on which both input and output data are presented. Currently, one of the trends in solving such problems is methods based on neural networks. Neural networks can be of various configurations (feedforward networks, radial-basis function networks, backpropagation networks, convolutional networks, etc.), have a different number of layers and neurons.</p><p>In this research, we consider the test and real-world example. A site with a known position of the sedimentary cover bottom is considered as a test model. To verify and compare the algorithms, the gravity and magnetic effects of the layer are calculated. The gravity and magnetic fields were supplied to the input to the algorithms for constructing regression dependence and training the neural network. An incomplete model of the sedimentary cover was supplied to the input for training neural networks. The task was to restore the missing part. The parameter of the standard deviation of the original and reconstructed model was less than 2% for all types of neural networks.</p><p>As a real model, a site was considered where basement cover is only partially available. It was obtained as a result of seismic interpretation. All available geological and geophysical data were used to reconstruct the horizon. Models obtained using reconstruction algorithms can be additional information for further detailed description of the geological structure.</p><p>It should be noted that since neural networks help to find complex functional relationships between field parameters and attributes of the studied environment, they could be used in the tasks of complex interpretation of geological and geophysical data.</p>


2021 ◽  
Author(s):  
Jan Michalek ◽  
Kuvvet Atakan ◽  
Christian Rønnevik ◽  
Helga Indrøy ◽  
Lars Ottemøller ◽  
...  

<p>The European Plate Observing System (EPOS) is a European project about building a pan-European infrastructure for accessing solid Earth science data, governed now by EPOS ERIC (European Research Infrastructure Consortium). The EPOS-Norway project (EPOS-N; RCN-Infrastructure Programme - Project no. 245763) is a Norwegian project funded by National Research Council. The aim of the Norwegian EPOS e‑infrastructure is to integrate data from the seismological and geodetic networks, as well as the data from the geological and geophysical data repositories. Among the six EPOS-N project partners, four institutions are providing data – University of Bergen (UIB), - Norwegian Mapping Authority (NMA), Geological Survey of Norway (NGU) and NORSAR.</p><p>In this contribution, we present the EPOS-Norway Portal as an online, open access, interactive tool, allowing visual analysis of multidimensional data. It supports maps and 2D plots with linked visualizations. Currently access is provided to more than 300 datasets (18 web services, 288 map layers and 14 static datasets) from four subdomains of Earth science in Norway. New datasets are planned to be integrated in the future. EPOS-N Portal can access remote datasets via web services like FDSNWS for seismological data and OGC services for geological and geophysical data (e.g. WMS). Standalone datasets are available through preloaded data files. Users can also simply add another WMS server or upload their own dataset for visualization and comparison with other datasets. This portal provides unique way (first of its kind in Norway) for exploration of various geoscientific datasets in one common interface. One of the key aspects is quick simultaneous visual inspection of data from various disciplines and test of scientific or geohazard related hypothesis. One of such examples can be spatio-temporal correlation of earthquakes (1980 until now) with existing critical infrastructures (e.g. pipelines), geological structures, submarine landslides or unstable slopes.  </p><p>The EPOS-N Portal is implemented by adapting Enlighten-web, a server-client program developed by NORCE. Enlighten-web facilitates interactive visual analysis of large multidimensional data sets, and supports interactive mapping of millions of points. The Enlighten-web client runs inside a web browser. An important element in the Enlighten-web functionality is brushing and linking, which is useful for exploring complex data sets to discover correlations and interesting properties hidden in the data. The views are linked to each other, so that highlighting a subset in one view automatically leads to the corresponding subsets being highlighted in all other linked views.</p>


2019 ◽  
Vol 7 (4) ◽  
pp. T857-T867 ◽  
Author(s):  
Mei Liu ◽  
Irina Filina ◽  
Paul Mann

We have investigated the crustal structure of a 400 km wide zone of thinned continental crust in the northeastern Gulf of Mexico (GOM) using gravity and magnetic modeling along two deeply penetrated seismic transects. Using this approach, we identify two zones of prominent, southward-dipping reflectors associated with 7–10 km thick, dense, and highly magnetic material. Previous workers have interpreted the zones as either coarse clastic redbeds of Mesozoic age that are tilted within half-grabens or seaward-dipping reflectors of magmatic origin. Both seismic reflection lines reveal a 10 km thick and 67 km wide northern zone of high density near the Florida coastline beneath the Apalachicola rift (AR). The southern zone of high density occurs 70 km to the south in the deepwater central GOM along the northern flank of the marginal rift, a 48 km wide, southeast-trending structure of inferred Late Jurassic age that is filled by 3 km of low-density and low-magnetic susceptibility sediments including complexly deformed salt deposits. We propose that these two subparallel rifts and their associated magmatic belts formed in the following sequence: (1) AR formed during Triassic-early Jurassic (210–163 Ma) phase 1 of diffuse continental stretching and was partially infilled on its northern edge by southward-dipping volcanic flows; and (2) the similarly southward-dipping southern magmatic zone formed adjacent to the marginal rift during the early phase 2 of late Jurassic (161–153 Ma) rifting of the GOM continental extension; this southern area of SDR formation immediately preceded the formation of the adjacent oceanic crust that separated the rift-related evaporates into the northern and southern GOM. Our integrated approach combining 2D seismic, gravity, and magnetic data sets results in a more confident delineation of these deep crustal features than from seismic data alone.


2013 ◽  
Vol 195 (3) ◽  
pp. 1745-1762 ◽  
Author(s):  
A. Sosa ◽  
A. A. Velasco ◽  
L. Velazquez ◽  
M. Argaez ◽  
R. Romero

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