Carlos Ortiz-Aleman

Centro de Investigación Científica de Yucatán | CICY · Water Science Unit

We present a 3D high-resolution modeling methodology based on the interpretation of gravity gradient data and its joint inversion with the simulated annealing (SA) global optimization method. The geometry of the model, used as computational domain in the solution of the forward and inverse problems, is defined with an irregular ensemble of cubic pr...

It is of particular importance for structural geology, geophysical exploration and also obvious economical purposes to retrieve structures possibly hidden below salt domes. And these domes could trap hydrocarbon or gas. We thus propose a sensitivity analysis of seismic data in salt tectonic areas to identify different wavelengths associated with th...

The Mexican subduction zone is a complex convergent margin characterized by a slab with an unusual morphology, an abnormal location of the volcanic arc, and the existence of slow earthquakes (slow slip events and tectonic tremors). The number of seismic imaging studies of the Mexican subduction zone has increased over the past decade. These studies...

Large impact structures are characterized by peak ring and central uplifts with lateral/vertical mass transport during late formation stages. Here we investigate the Chicxulub crater, which has been surveyed by an array of marine, aerial and land-borne geophysical methods. Seismic reflection surveys in its central sector have shown lack of resoluti...

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...

It is well known that high impedance contrasts between salt bodies and their surroundings yield blurriness in seismic images which does not allow adequate interpretation; some of the artifacts generated by this process are multiple reflections and diffractions. In this work we propose a novel method of detection and attenuation of multiples from se...

In this work we develop a mathematical model to estimate the error for inverse kinematics problem for Gough-Stewart parallel mechanisms. We propose the estimation error method to include manufacture, assembly, backlash and sensoring errors. We provide the error transmission matrices for the length of each leg of the hexapod, which permits to evalua...

The effects of high-energy particles coming from the Sun in human health as well as in the integrity of outer space electronics make prediction of periods of high solar activity a task of significant importance. Since periodicities in solar indexes have been identified, long-term predictions can be achieved. In this paper, we present a method based...

In this work, the Electrical Capacitance Tomography (ECT) technique is applied in monitoring internal deformation of geological analog models, which are used to study structural deformation mechanisms, in particular for simulating migration and emplacement of allochtonous salt bodies. A rectangular ECT sensor was used for internal visualization of...

A parameterized source and path effects inversion method based on the use of global optimization techniques is presented. We applied this method on velocity data from various seismic events collected between August, 2005 and April, 2007 in Mexico by the regional MesoAmerican Subduction Experiment (MASE) seismic network and other stations from the p...

A parameterized source and path effects inversion method based on the use of global optimization techniques is presented. We applied this method on velocity data from various seismic events collected between August, 2005 and April, 2007 in Mexico by the regional MesoAmerican Subduction Experiment (MASE) seismic network and other stations from the p...

Los efectos de las partículas ultra-energéticas provenientes del sol en la salud humana así como en la ingtegridad de equipo electronico espacial, hacen de la predicción de periodos de alta actividad solar una tarea de gran importancia. Dado que se han encontrado periodicidades en los registros solares, se pueden lograr predicciones a largo plazo....

We present a novel approach to automated volume extraction in seismic data and apply it to the detection of allochthonous salt bodies. Using a genetic algorithm, we determine the optimal size of volume elements that statistically, according to the U-test, best characterize the contrast between the textures inside and outside of the salt bodies thro...

We present a three-dimensional (3D) gravity modeling and inversion approach and its application to complex geological settings characterized by several allochthonous salt bodies embedded in terrigenous sediments. Synthetic gravity data were computed for 3D forward modeling of salt bodies interpreted from Prestack Depth Migration (PSDM) seismic imag...

The analytic solution of the gravimetric tensor components, making use of the gravitational potential equation for a three-dimensional volumetric assembly composed of unit prisms of constant density, demands a high computational cost. This is due to the gravitational potential of each one of these prisms must be calculated for all of the points of...

In this work an implementation with the CUDA technology in a single and in several graphics processing units (GPUs) of NVIDIA TESLA model is presented for the calculation of the direct modeling of gravimetric and gradiometric data from a tridimensional volumetric ensemble composed by unitary prisms of constant density.For this problem a previous im...

We present a novel method to enhance seismic data for manual and automatic interpretation. We use a genetic algorithm to optimize a kernel that, when convolved with the seismic image, appears to enhance the internal characteristics of salt bodies and the sub-salt stratigraphy. The performance of the genetic algorithm was validated by the use of tes...

An implementation with the CUDA technology in a single and in several graphics processing units (GPUs) is presented for the calculation of the forward modeling of gravitational fields from a tridimensional volumetric ensemble composed by unitary prisms of constant density. We compared the performance results obtained with the GPUs against a previou...

This work is aimed to obtain numerical results that allow the detection and characterization of subsurface discontinuities in metallic materials by the application of Rayleigh compression and shear elastic waves. The solution is obtained from boundary integral equations, which belong to the field of elasto-dynamics. Subsequent to the implementation...

This work shows the wave propagation in fluid-solid interfaces due to dynamic excitations. The interface connects an acoustic medium (fluid) and a solid one, a wide range of elastic solid materials is considered. By means of an analysis of diffracted waves in a fluid, it is possible to deduce the mechanical characteristics of the solid medium, spec...

We present a novel method to enhance seismic data for manual and automatic inter-pretation. We use a genetic algorithm to optimize a kernel that, when convolved withthe seismic image, appears to enhance the internal characteristics of salt bodies andthe sub-salt stratigraphy. The performance of the genetic algorithm was validated bythe use of test...

This study uses the deconvolution of small earthquakes registered in the SMNH01 station of KiK-net, one of the most important seismic networks which is located in Japan, to estimate effective shear wave velocities Β, shear modulus μ, and quality factors Q, and to identify physical changes in the soil. This station has a borehole which is equipped w...

This work shows the wave propagation in fluid-solid interfaces due to dynamic excitations. The interface connects an acoustic medium (fluid) and a solid one, a wide range of elastic solid materials is considered. By means of an analysis of diffracted waves in a fluid, it is possible to deduce the mechanical characteristics of the solid medium, spec...

Since interpretation of seismic data is usually a tedious and repetitive task, the ability to do so automatically or semi-automatically has become an important objective of recent research. We believe that the vagueness and uncertainty in the interpretation process makes fuzzy logic an appropriate tool to deal with seismic data. In this work we dev...

The Green's function can be retrieved from averaging cross correlations of recorded motions within a diffuse field. When autocorrelation is performed the energy density at a point is proportional to the trace of the imaginary part of the Green's function tensor at the source itself. This is because the singularity of the Green's function is restric...

In this paper scattering of elastic waves in fluid–solid interfaces is investigated. We use the Indirect Boundary Element Method to study this wave propagation phenomenon in 2D models. Three models are analyzed: a first one with an interface between two half-spaces, one fluid on the top part and the other solid in the bottom; a second model includi...

In earthquake engineering and seismology it is of interest to know the surface motion at a given site due to the incoming and scattered seismic waves by surface geology. This can be formulated in terms of diffraction of elastic waves and then the indirect boundary element method (IBEM) for dynamic elasticity is used. It is based on the explicit con...

In this work two novel image processing techniques are applied to detect and delineate complex salt bodies from seismic exploration profiles: Hough transform and principal component analysis (PCA). It is well recognized by the geophysical community that the lack of resolution and poor structural identification in seismic data recorded at sub-salt p...

The analytic benchmark solution for the scattering and diffraction of elastic P- and S-waves by a single spherical obstacle is presented in a condensed format. Our aim is divulge to the scientific community this not widely known classical solution to construct a direct seismic model for 3D objects. Some of the benchmark papers are frequently plague...

The analytic signal method and forward modeling in three dimensions are applied to magnetic field data over the Chicxulub crater in order to determine and document the main magnetic anomaly sources and crater structure in the central zone. Aeromagnetic data over the structure reveal three strong, well-defined concentric patterns, with a central 40-...

The scattering and diffraction of Rayleigh waves by shallow cracks using the indirect boundary element method (IBEM) are investigated. The detection of cracks is of interest because their presence may compromise structural elements, put technological devices at risk or represent economical potential in reservoir engineering. Shallow cracks may give...

Analytic signal, inversion and forward models in three-dimensions are applied to magnetic field over the Chicxulub crater to investigate magnetic anomaly sources and crater structure in the central zone. Aeromagnetic data show three strong, well-defined concentric patterns, with a central 40-km diameter zone of high amplitude anomalies. Magnetic an...

The invention relates to an image-reconstruction technique which is used to view multiphase flows using electrical capacitance tomography (ECT), which is based on non-linear heuristic global optimization methods involving simulated annealing and genetic algorithms. The inventive method consists in obtaining electrical capacitance data which are mea...

In this work we apply an acoustic wave model in two dimensions in order to simulate a real seismic acquisition. The main goal is to find optimal parameters (azimuth, position of receivers and sources) for seismic acquisition in zones with presence of salt Tectonics in the Gulf of Mexico. The model is built by using a varying order finite difference...

In this work we applied a three-dimensional high-resolution gravity inversion method based on simulated annealing to the imaging of salt structures in the Gulf of Mexico. The initial input solution was constrained by using a previously interpreted seismic velocity model and all the available geologic information. Conversion of seismic velocities in...

In this work we apply a highly optimized three-dimensional gravity inversion method based on simulated annealing to the imaging of salt structures in the Gulf of Mexico. The initial input solution was constrained by using a previously interpreted seismic velocity model and all the available geologic information. Conversion of seismic velocities int...

We introduce a numerically improved inversion approach for 3D potential field modeling based on simulated annealing. In this simulated annealing inversion method, a large linear system of algebraic equations is solved by minimizing iteratively an energy function. The vector of unknown densities is repeatedly updated, in a semi-random process that m...

Multiphase flow characterization is an important task for monitoring, measuring or controlling industrial processes. This can be done by means of process tomography. The use of tomographic techniques has been used within the oil industry. One of the potential applications is flow visualization and measurement in producing wells. Research on industr...

A highly optimized simulated annealing (SA) algorithm is applied to reconstruct permittivity images of real two-phase gas-oil flows through a cylindrical vessel using electrical capacitance tomography (ECT). ECT yields low-accuracy images but is robust, inexpensive and much faster than many other tomography processes. This non-intrusive method esse...

Electrical Capacitance Tomography (ECT) is a novel technology that can deal with the complexity of two-phase gas-oil flow measurement by explicitly deriving the component distributions on two adjacent planes along a pipeline. One of its most promising applications is the visualization of gas-oil flows. ECT offers some advantages over other tomograp...

In this work we apply a highly optimized simulated annealing (SA) inversion method to the reconstruction of permittivity images from real two-phase gas–oil flow electrical capacitance tomography (ECT) data. We test the SA inversion method using several flow regimes generated by varying gas and oil flow rates in a test loop facility. The SA-based pe...

In this work we apply the simulated annealing (SA) inversion method to the reconstruction of permittivity images from electrical capacitance tomography (ECT) data. We test the SA inversion method using static physical models simulating some typical distribution patterns of two and three-component flows. The SA-based permittivity inversions have som...

We introduce a numerically improved image reconstruction technique for imaging two-phase oil–gas pipe flows using electrical capacitance tomography, based on simulated annealing and iterative linear forward modelling. In the simulated annealing method, a permittivity image is reconstructed by minimizing iteratively an energy function related to the...

In this paper we introduce an image reconstruction technique for imaging permittivity distributions using electrical capacitance tomography, based on global optimization by very fast simulated annealing. Electrical capacitance measurement data are obtained between electrodes placed around the outer wall of an electrically insulating pipe. Such data...

The Zafarraya Basin is one of the intramountain Neogene basins of the Betic mountains (Southern Spain) located in one of the regions with the highest hazard level in the Iberian Peninsula. In this paper we use the indirect boundary element method (IBEM) to compute the 3-D ground motion of the Zafarraya Basin under incident P and S waves. We solve t...

The linear back-projection (LBP) algorithm was one of the first methods employed to perform image reconstruction in electrical capacitance tomography. Despite its relatively poor accuracy, it is a simple and fast procedure capable of real-time operation in many applications, and it has remained a popular choice. However, since it was first reported...

In this work we apply the simulated annealing (SA) and genetic algorithms (GA) inversion methods to the reconstruction of permittivity images from electrical capacitance tomography (ECT) measurements. The forward problem (i.e., to find the mutual capacitance data for a given permittivity distribution in the sensor) is calculated by using a finite-v...

The Zafarraya basin is one of the intramountain Neogene basins of the Betic mountains (South Spain) located in one of the regions with the highest hazard level in the Iberian Peninsula. In this paper we use the Indirect Boundary Element Method (IBEM) to compute the 3D ground motion of the Zafarraya basin under incident P and S waves. In this study...

Boundary element methods have been applied to calculate the seismic response of various types of geological structures. Dimensionality reduction and a relatively easy fulfillment of radiation conditions at infinity are recognized advantages over domain approaches. Indirect Boundary Element Method (IBEM) formulations give rise to large systems of eq...

Electrical capacitance tomography (ECT) is a technique for obtaining crosssectional images of the electrical permittivity distribution inside an electrically non-conducting body. It can be used to map the composition of two-phase mixtures like gas-oil systems and provides a useful tool for multiphase flow visualization and measurement and potential...

The Granada Basin is located in the southeast of Spain, in the central sector of the Betic Cordilleras, in an area of high seismic hazard in the Iberian Peninsula. This hazard is due, in part, to local ground-motion amplification effects that have been observed at various locations in this basin. In this work, we use the indirect boundary element m...

Mediante los métodos de inversión global denominadas algoritmos genéticos y recocido simulado (simulated annealing) se modelan los datos de campo magnético sobre la estructura de impacto de Chicxulub. Las anomalías aeromagnéticas sobre la estructura revelan tres rasgos concéntricos bien definidos, con una zona central de 40 km de diámetro que inclu...

En los últimos años se han dado avances significativos en el estudio de los impactos de meteoritos y cometas en la Tierra y en otros cuerpos del sistema solar. Estos estudios han permitido revalorar la importancia de estos procesos en la evolución geológica de nuestro planeta y en el sistema solar. En la Tierra, los diversos procesos geológicos han...

In this paper we study the seismic response of flat sedimentary basins and carry out numerical experiments to determine the extent to which we could go using the Horizontal to Vertical Spectral Ratio (HVSR) for a given site. The HVSR has been used by many researchers to characterize local conditions in terms of the dynamic response of the soil, and...

The analytic signal method in 3D is applied to the magnetic field data over the Chicxulub crater. In a second stage, source locations are used as a priori information in the construction of a prism-like magnetic configuration model.

We briefly review the basis of the indirect boundary element method (IBEM) and apply it to compute the seismic response of three-dimensional topographic features for incident P and S waves. The method is based on the integral representation for scattered and diffracted waves using single-layer boundary sources. This approach is called indirect beca...

Aside from its significance in establishing the impact-mass extinction paradigm, the Chicxulub crater will probably come to exemplify the structure of large complex craters. Much of Chicxulub’s structure may be ‘mapped’ by tying its gravity expression to seismic-reflection profiles revealing an ∼180 km diameter for the now-buried crater. The distri...

Among the class of global optimization techniques, which includes Monte Carlo and simulated annealing methods, the Genetic Algorithms constitute a new class of methods to solve highly non-linear optimization problems. The issue has generated considerable interest in the field of artificial intelligence, and recently, in some multi-parameter optimiz...

The buried Chicxulub impact structure is marked by a dramatic ring of sinkholes (called cenotes if containing water), and adjacent less prominent partial rings, which have been shown to coincide with maxima in horizontal gravity gradients and a topographic depression. These observations, along with the discreteness and spacing of the features, sugg...

Differing interpretations of the Bouguer gravity anomaly over the Chicxulub crater, Yucatan Peninsula, Mexico, have yielded diameter estimates of 170 to 320 km. Knowing the crater's size is necessary to quantify the lethal perturbations to the Cretaceous environment associated with its formation. The crater's size (and internal structure) is reveal...

IT is now widely believed that a large impact occurred on the Earth at the end of the Cretaceous period, and that the buried Chicxulub structure in Yucatan, Mexico, is the resulting crater(24). Knowledge of the size and internal structure of the Chicxulub crater is necessary for quantifying the effects of the impact on the Cretaceous environment. A...