# Khalid S. EssaCairo University | CU · Department of Geophysics

Khalid S. Essa

Professor

## About

90

Publications

32,690

Reads

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1,473

Citations

Introduction

Additional affiliations

June 2018 - February 2019

November 2014 - present

October 2014 - February 2015

Education

July 2001 - January 2004

January 1999 - June 2001

September 1993 - May 1997

## Publications

Publications (90)

This study focused on joint interpretation of the aeromagnetic and radiometric data to allocate and describe the structural elements and mineralization zones such as uranium, gold, and sulfide in the Gebel Umm Tineidba and its surroundings, Eastern Desert, Egypt. The study region is covered by exposures of Precambrian rocks such as gneisses, migmat...

Metaheuristic algorithms are increasingly being utilized as a global optimal method in the inversion and modeling of magnetic data. We proposed the Bat Algorithm Optimization (BAO) technique that is based on bat echolocation performance to find the global optimum solution. The best-estimated source parameters that correspond to the objective functi...

We investigated 22 different serpentinization level peridotite samples from the North Pyrenean Zone (NPZ) and along the North Pyrenean Fault (NPF) to characterize their mineralogical composition and petrophysical properties (bulk and grain density, porosity, compressional and shear wave velocities and thermal conductivity and diffusivity). Peridoti...

Recently gravity data modeling plays an important role in the study of volcanic activity and geothermal investigation. Generally, gravity data modeling assumes the subsurface either homogenous or spatially variable densities within modeled source rocks and surrounding sediments. As a result, the subsurface geothermal and volcanic goals and targets...

Rapid imaging technique, so-called “R-parameter”, utilized for interpreting a gravity anomaly profile. The R-parameter based on calculating the correlation factor between the analytic signal of the real anomaly and the analytic signal of the forward anomaly of assumed buried source denoted by simple geometric shapes. The model parameters (amplitude...

An interpretation for the gravity anomalies is essential to visualize the horizontal and vertical extension of the subsurface intrusion like mud diapirs resembling dike-like geologic bodies. Therefore, the use of simple-geometrical resembling models helps to validate the subsurface targets. A particle optimization algorithm is one of the recently e...

Herein, the gravity anomalies are a function of horizontal variations in subsurface rock densities; therefore, the interpretation of gravity anomalies is useful in prospecting the provinces that have contrasting geological structures, which contain crypts, minerals, ores, and hydrocarbon deposit. Depth-size relationships due to geological considera...

A comparison study using the least-squares minimization method, particle swam optimization method, and neural network method for interpreting self-potential data for typical shaped-models (spheres and cylinders). This interpretation process contains the delineation buried sources parameters, which are the amplitude factor, the depth to the structur...

We establish a method to elucidate the magnetic anomaly due to 2D fault structures, with an evaluation of first moving average residual anomalies utilizing filters of increasing window lengths. After that, the buried fault parameters are estimated using the global particle swarm method. The goodness of fit among the observed and the calculated mode...

This study focuses on interpreting Bouguer gravity anomalies by two-sided fault structures. Faults have prime concerns for hazardous zones, mineralized areas, and hydrocarbon systems. The proposed scheme is done through the following steps: first, it utilizes the residual moving average anomalies estimated from the Bouguer gravity anomalies using s...

This study focuses on interpreting gravity anomalies caused by fault structures. The faults types are the two-sided inclined fault, which represents mainly the normal and reverse faults, the two-sided vertical fault, the one-sided inclined fault, and the one-sided vertical fault. The study scheme is depends on the combination between the second mov...

The detection of buried geometrical model parameters is vital to full interpretation of potential field data, especially that related to gravity and/or self-potential anomalies. This study introduced a proposed non-linear least-squares algorithm for solving a combined formula for gravity and self-potential anomalies due to simple geometric shapes....

We have developed a new method for the interpretation of a magnetic anomaly profile by idealized-geometrical bodies using the variance analysis. This method is based on estimating the fourth horizontal derivative of the magnetic data profile. The advantage behind the use of the fourth horizontal derivative method is to reduce the regional backgroun...

We have developed a scheme for the interpretation of gravity data by a two-sided fault-like geological structure. The scheme is based on the particle swarm optimization and determines the model parameters of the upthrown and downthrown of the fault. It uses the second horizontal derivatives, which are calculated numerically from the measured gravit...

This paper describes a fast imaging technique, the so-called here the “R-parameter imaging technique”, for the interpretation of gravity data measured along profile. The technique calculates the R-parameter (a statistical parameter called the correlation coefficient) between the analytic signal of the measured gravity field and that of the syntheti...

A new imaging method has been developed for elucidating the observed magnetic data gauged along profile. The method is based on the calculation of the correlation factor (the R-parameter) between the analytic signal of the measured magnetic anomaly and the analytic signal of the calculated response of some geometrically simple interpretive models i...

A new approach to the inversion of gravity data utilizing the Particle Swarm Optimization (PSO) algorithm is used to model 2D vertical faults. The PSO algorithm is stochastic in nature; its development was motivated by the communal in-flight performance of birds looking for food. The birds are represented by particles (or models). Individual partic...

A global particle swarm algorithm utilized to assess the inverted two-dimensional horizontal thin sheet parameters from the gravity anomaly profile based on applying the second moving average method. The using of the second moving average method has more advantageous than using the Bouguer gravity anomaly because this method has a capability in eli...

A combined gravity and/or self-potential anomaly formula is utilized to estimate the model parameters of the buried geologic structures represented by simple geometric. The simple geometric shapes (spheres, cylinders, and sheets) are not really found but often applied to reduce the nonuniqueness in interpreting the gravity and self-potential data....

We have developed an algorithm to obtain the model parameters for two co-axial structures from self-potential data. The method uses the first numerical horizontal derivatives calculated from the observed self-potential anomaly employing filters of sequential window lengths (s-values) so as to gauge the model constraints for the shallow and deep str...

The self potential data interpretation is very important to delineate and trace the mineralized zones in several regions. We study how to interpret self potential anomalies due to a finite two-dimensional inclined dike using the particle swarm algorithm. However, the precise estimation of the model parameters during the inverse solution are unknown...

This paper emphasizes the use of the particle swarm optimization to infer second moving average residual magnetic anomalies. This approach was used to remove the impact of the regional background up to the third-order polynomial by applying filters of successive window lengths. The body parameters evaluated are the amplitude coefficient, depth, mag...

It can be demonstrated that magnetic data have diverse applications and can be used to study different geological provinces. We used six distinct numerical strategies for the body parameters (depth, origin, half-width, index angle and amplitude Coefficient) assessment of a 2D inclined dike like a geologic structure. These different strategies are t...

The book "Minerals" offers an important and thorough overview on different geophysical methods including gravity, magnetic and self-potential in mineral exploration, as well as physical and chemical analysis in delineating the minerals. Furthermore, the book describes the different types of minerals such as clay and its minerals, and uranium (which...

This paper describes a new method based on the particle swarm optimisation (PSO) technique for interpreting the second moving average (SMA) residual gravity anomalies. The SMA anomalies are deduced from the measured gravity data to eradicate the regional anomaly by utilising filters of consecutive window lengths (s-value). The buried structural par...

This paper describes the use of the particle swarm optimization (PSO) method for interpreting observed self-potential anomalies measured along a profile. First, the technique applies the second moving average to the observed self-potential data in order to eradicate the possible influence of the regional anomaly (up to the third-order polynomial ef...

Spatial information about soils generally results from local observations which are destructive and time consuming. Geophysical techniques could help soil mapping since they are non-destructive and fast. Electrical resistivity is interesting for soil studies due to a wide range of values and as it depends on soil characteristics. This work aims to...

A new algorithm has been established to interpret magnetic anomaly data due to inclined dike-like structure. This algorithm uses first horizontal derivative anomalies attained from magnetic anomaly data utilizing filters of sequential window lengths. The final estimated parameters are the half-width, the depth, angle of magnetization and amplitude...

The near-surface groundwater aquifer that threatened the Great Pyramids of Giza, Egypt, was investigated using integrated geophysical surveys. A total of 10 electrical resistivity imaging, 26 shallow seismic refraction, and 19 ground-penetrating radar surveys were conducted in the Giza Plateau. Collected data for each method were evaluated by state...

A new efficient approach to estimate parameters that controlled the source dimensions from magnetic anomaly profile data in light of PSO algorithm (particle swarm optimization) has been presented. The PSO algorithm has been connected in interpreting the magnetic anomaly profiles data onto a new formula for isolated sources embedded in the subsurfac...

A new approach is developed to depict the fault lineaments and pertinent tectonic evidence of the Sinai Peninsula, Egypt from gravity and magnetic data. The approach is capable of identifying not only the main basements trends, but also the main trends of the sedimentary structures. The main lineaments trends in the Peninsula were derived from the...

Geophysical studies were performed along selected locations across the Pyramids Plateau to investigate the groundwater table and the near aquifer, which harmfully affected the existed monuments of the Giza Pyramids and Sphinx. Electrical Resistivity Imaging (ERI), Shallow Seismic Refraction (SSR) and Ground Penetrating Radar (GPR) techniques were c...

A robust Particle Swarm Optimization (PSO) investigation for magnetic data by a 2D dipping dike has been presented. The interpretive model parameters are: the amplitude coefficient (K), the depth to the top of the dipping dike (z), exact origin of the dipping dike (x0), and the width of dipping dike (w). The inversion procedure is actualized to gau...

The integration between advanced techniques for groundwater exploration is necessary to manage and protect the vital resources. Direct current (DC) resistivity geoelectrical technique, Enhanced Thematic Mapper Landsat (ETM+) images and a geographic information system (GIS) are integrated to identify the groundwater potentiality in the study area. T...

Geophysical studies were performed along selected locations across the Pyramids Plateau to investigate the groundwater table and the near aquifer, which harmfully affected the existed monuments of the Giza Pyramids and Sphinx. Electrical Resistivity Imaging (ERI), Shallow Seismic Refraction (SSR) and Ground Penetrating Radar (GPR) techniques were c...

We have developed a new algorithm for the interpretation of magnetic data measured along a profile by a dipping dike like body. The algorithm is based on the second horizontal gradient (SHG) anomalies calculated from the observed magnetic data using filters of successive window lengths (s). The main merit of this new method is its capability to est...

In the present paper, we have developed a least-squares minimization approach to estimate simultaneously the depth and the width of a buried 2D thin sheet from moving average residual gravity anomalies using the window-curves method. The method involves fitting the 2D thin sheet model convolved with the same moving average filter as applied to the...

A new two-and-a-half dimensional (2.5D) regularized inversion scheme has been developed for the interpretation of residual gravity data by a dipping thin-sheet model. This scheme solves for the characteristic inverse parameters (depth to top z, dip angle θ, extension in depth L, strike length 2 Y, and amplitude coefficient A) of a model in the spac...

A new linear least-squares approach is proposed to interpret magnetic anomalies of the buried structures by using a new magnetic anomaly formula. This approach depends on solving different sets of algebraic linear equations in order to invert the depth (z), amplitude coefficient (K), and magnetization angle (θ) of buried structures using magnetic d...

We have developed a simple and fast numerical method to simultaneously determine the depth and shape of a buried structure from second moving average residual anomalies obtained from magnetic data with filters of successive window lengths. The method is similar to Euler deconvolution, but it solves for depth and shape independently. The method invo...

In this paper, we develop a method to determine the depth to two superimposed sources from a self-potential anomaly profile. The method is based on finding a relationship between the depths to the two superimposed structures from a combination of observations at symmetric points with respect to the coordinate of the sources' centre. Formulae have b...

We present in this paper a new formula representing the magnetic anomaly expressions produced by most geological structures. Using the new formula we developed a simple and fast numerical method to determine simultaneously the depth and shape of a buried structure from second-horizontal derivative anomalies obtained from magnetic data with filters...

We have developed three different least-squares minimization approaches to determine, successively, the depth, dip angle, and amplitude coefficient related to the thickness and density contrast of a buried dipping fault from first moving average residual gravity anomalies. By defining the zero-anomaly distance and the anomaly value at the origin of...

A new fast least-squares method is developed to estimate the shape factor (q-parameter) of a buried structure using normalized residual anomalies obtained from gravity data. The problem of shape factor estimation is transformed into a problem of finding a solution of a non-linear equation of the form f(q) = 0 by defining the anomaly value at the or...

In this paper, we have developed a new least-squares minimisation approach to determine the depth of a buried faulted structure approximated by a 2D semi-infinite horizontal slab from second moving average residual gravity anomalies. The problem of depth determination has been transformed into a problem of finding the solution to a nonlinear equati...

We have developed a least-squares method to determine simultaneously the depth and the dip angle of a buried fault from first moving average residual gravity anomalies using filters of successive window lengths. The method involves using a relationship between the depth and the dip angle of the source and a combination of windowed observations. The...

A new algorithm is developed to estimate simultaneously the depth and the dip angle of a buried fault from the normalized gravity gradient data. This algorithm utilizes numerical first horizontal derivatives computed from the observed gravity anomaly, using filters of successive window lengths to estimate the depth and the dip angle of a buried dip...

An inversion technique using a fast least-squares method is developed to estimate, successively, the shape factor (q-parameter), the depth (z-parameter) and the amplitude coefficient (A-parameter) of a buried structure using normalized residual anomalies obtained from gravity data. By defining the anomaly value at the origin and the anomaly value a...

We have developed a simple method to determine the depth, inclination
parameter and amplitude coefficient of a buried structure from a
residual magnetic anomaly profile using a new formula representing the
magnetic anomaly expressions produced by most geological structures. The
method is based on defining the anomaly value at the origin and four
ch...

An inversion technique using a fast method is developed to estimate, successively, the depth, the shape factor, and the amplitude coefficient of a buried structure using residual gravity anomalies. By defining the anomaly value at the origin and the anomaly value at different points on the profile, the problem of depth estimation is transformed int...

Rapid techniques for self-potential (SP) data interpretation are of prime importance in engineering and exploration geophysics. Parameters (e.g. depth, width) estimation of the ore bodies has also been of paramount concern in mineral prospecting. In many cases, it is useful to assume that the SP anomaly is due to an ore body of simple geometric sha...

An inversion algorithm is developed to estimate the depth and the associated model parameters of the anomalous body from the gravity or self-potential (SP) whole measured data. The problem of the depth (z) estimation from the observed data has been transformed into a nonlinear equation of the form F(z) = 0. This equation is then solved for z by min...

An inversion algorithm is developed to estimate the depth and associated model parameters of the anomalous body from the gravity or self-potential (SP) whole measured data. The problem of the depth (z) estimation from the observed data has been transformed into a nonlinear equation of the form F(z) = 0. This equation is then solved for z by minimiz...

We have developed a new numerical method to determine the shape (shape factor), depth, polarization angle, and electric dipole moment of a buried structure from residual self-potential (SP) anomalies. The method is based on defining the anomaly value at the origin and four characteristic points and their corresponding distances on the anomaly profi...

This paper develops a least-squares minimisation approach to determine the depth of a buried structure from numerical second horizontal derivative anomalies obtained from self-potential (SP) data using filters of successive window lengths. The method is based on using a relationship between the depth and a combination of observations at symmetric p...

We have developed a least-squares method to determine simultaneously the depth and the horizontal position (origin) of a buried thin dike that extends in both strike direction and down dip (2D) and in which the depth is much greater than the thickness from horizontal gradients obtained numerically from magnetic data using filters of successive wind...

We have developed a semi-automatic method to determine the depth and shape (shape factor) of a buried structure from second moving average residual self-potential anomalies obtained from observed data using filters of successive window lengths. The method involves using a relationship between the depth and the shape to source and a combination of w...

We have developed a new least-squares minimization approach to depth determination from self-potential (SP) data. By defining the anomaly value at the origin and at any two symmetrical points around the origin on the profile, the problem of depth determination from the residual SP anomaly has been transformed into finding a solution to a nonlinear...

We have developed a new least-squares inversion approach to determine successively the depth (z), polarization angle, and electric dipole moment of a buried structure from the self-potential (SP) anomaly data measured along a profile. This inverse algorithm makes it possible to use all the observed data when determining each of these three paramete...

We have developed an automatic method to determine the depth of a buried sphere from numerical second horizontal derivative
anomalies obtained from total field magnetic data. The method is based on using a relationship between the depth and a combination
of observations at symmetric points with respect to the coordinate of the projection of the cen...