Eslam Elawadi
King Saud University, Exploration, Faculty Member
- Earth Sciences, Geology, Exploration, GRAVITY ANOMALIES INTERPRETATION, Euler Deconvolution, Geophysical Investigation at Faulted Building, and 22 moreGeology & Geophysics, Groundwater Investigation using geophysical methods, Resistivity Method Groundwater Exploration, Methods of Groundwater Exploration, Geographic Information Systems (GIS), Environmental Engineering, Hydrology, Water resources, Hydrogeology, Geophysics, Environmental Management, Geomorphology, Sedimentology, Tectonics, Stratigraphy, Quaternary Geology, GPS Applications, Sedimentary geology and stratigraphy, Integrated Water Resources Management, Seismic, Geomorphology and Active tectonics, and Quaternary Sedimentology and Geomorphologyedit
- Eslam Elawadi Professor of Applied Geophysicsedit
An integrated geophysical survey was carried out in a new dwelling area at 15-May town, southeast Cairo, Egypt. The buildings in this area are intensively affected by dangerous cracks that cause structural instability. The survey aimed to... more
An integrated geophysical survey was carried out in a new dwelling area at 15-May town, southeast Cairo, Egypt. The buildings in this area are intensively affected by dangerous cracks that cause structural instability. The survey aimed to image the shallow subsurface structures, including karstic features, and evaluate their extent, as they may cause rock instability and lead to cracking of the residential buildings. Resistivity profiling (2-D), using a dipole-dipole array and ground penetrating radar (GPR) surveys were carried out along seven parallel traverses extending about [Formula: see text] between the buildings blocks. Additional measurements using a Schlumbereger array and very low frequency electromagnetic (VLF-EM) methods were conducted. The acquired data were processed and interpreted integrally to elucidate the shallow structural setting of the site. Integrated interpretation led to the delineation of hazard zones rich with karstic features in the area. Most of these ka...
Research Interests: Environmental Engineering, Geology, Geophysics, Ground Penetrating Radar, Seismology, and 9 moreVery Low Frequency Electromagnetics, Geophysical Survey, Instability, Site Investigation, Karst, ELECTRICAL RESISTIVITY TOMOGRAPHY, Engineering and environmental geophysics, Electric Dipole Moments, and building block
Abstract Effective management and planning for the sustainable development of urban regions requires a wide range of up-to-date and impartial information. This study focusses on earthquake catalog-based seismicity analysis for Cyprus... more
Abstract Effective management and planning for the sustainable development of urban regions requires a wide range of up-to-date and impartial information. This study focusses on earthquake catalog-based seismicity analysis for Cyprus region. It is followed by computation of seismic features and short-term prediction of seismic activity using machine learning techniques. Earthquake catalog is investigated temporally and noisy data is removed. Sixty seismic features were then computed based upon cleaned earthquake catalog to express the internal seismic state of the region. These seismic features are then modeled using machine learning techniques with the corresponding seismic activity. Three machine learning algorithms, namely Artificial Neural Networks, Support Vector Machines and Random Forests, are employed for seismic activity prediction. The framework is designed to obtain five days-ahead, one week-ahead, ten days-ahead and fifteen days-ahead predictions for moment magnitude thresholds of 3.0, 3.5, 4.0 and 4.5. Based on the Matthews correlation coefficient (MCC), the predictions obtained using the Random Forest were found to be the most accurate for magnitude thresholds of 3.0 and 3.5 across all the prediction periods. Similarly, the predictions obtained using the Support Vector Machine outperformed other techniques for magnitude thresholds of 4.0 and 4.5.
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The Uyaijah ring structure (URS), situated within the Precambrian Kushaymiyah Igneous Complex (KIC) at the eastern edge of the Arabian Shield, consists of three large laccoliths: two granitic and one granodioritic, intruded by late mafic... more
The Uyaijah ring structure (URS), situated within the Precambrian Kushaymiyah Igneous Complex (KIC) at the eastern edge of the Arabian Shield, consists of three large laccoliths: two granitic and one granodioritic, intruded by late mafic dikes. The transverse fault zone (TFZ), belonging to the Najd Fault System of Saudi Arabia, transects the URS along its major axis. The digital elevation map for the URS is first correlated with surface geology to clarify the effects of faulting on the elevation of the pluton. Next, the complete (terrain-corrected) Bouguer anomaly (CBA) map for the URS, based on 145 gravity stations, is examined to investigate the source of the URS through 3D-gravity inversion modeling. A pronounced CBA “low” (< 50 mgal amplitude) occupies the central part of the URS; this is interpreted as the lower density root of the pluton. Three-dimensional gravity inversion modeling traces the source magmatic body through sections at 2–10 km below sea level; this model is largely complemented by results from the 3D magnetic inversion of the RTP aeromagnetic anomalies. The gravity-magnetic inversion indicates that the pluton root zone lies below the SW of the URS at ~ 10-km depth; this value is significantly different from previous depth estimates of ~ 4.75 km. The root zone is noticeably offset by the TFZ. These results suggest a genetic relationship between pluton expansion and updoming, dyking, and faulting that probably reaches down to the base of the upper crust, involving pulsed emplacement.
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Western Saudi Arabia is one of the arid areas which occasionally subjected to flash flooding effects due to excessive rainfall. The most important and holiest areas in this region are Makkah and El-Madeina which are of great importance... more
Western Saudi Arabia is one of the arid areas which occasionally subjected to flash flooding effects due to excessive rainfall. The most important and holiest areas in this region are Makkah and El-Madeina which are of great importance not only to Saudi people, but also for ...
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Geoelectrical resistivity surveys were carried out in Al Quwy’yia area, located at the centeral part of Saudi Arabia, to map the acquifer and estimate the groundwater potentuality. The acquired vertical electrical sounding (VES) data sets... more
Geoelectrical resistivity surveys were carried out in Al Quwy’yia area, located at the centeral part of Saudi Arabia, to map the acquifer and estimate the groundwater potentuality. The acquired vertical electrical sounding (VES) data sets have been collected along three longitudinal profiles trending East-West, perpendicular to the basment/sedimentary contact. The data sets have been analysed using 1D to obtain the initial figure out of the resistivity layers along the areas. Then, the data were inversion resistivity section using 2D inversion scheme. Information from two boreholes were incorporated during the processing to enhance the results and constrain the resistivity models with geological layers. The results revealed mainly two geoelectric layers represent mainly the basement and sedimentary rocks. The basement rocks dip generally east ward, where the sedimentary section increases in this direction. The depth to the basement is about 50 m in the western part of the area and c...
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We have developed a simple approach to determine the depth and radius of subsurface cavities from microgravity data. The horizontal location of cavity centre is picked up as the projection of the minimum of gravity anomaly. Depth to the... more
We have developed a simple approach to determine the depth and radius of subsurface cavities from microgravity data. The horizontal location of cavity centre is picked up as the projection of the minimum of gravity anomaly. Depth to the cavity centre is estimated using a back ...
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Hohi area is located in central Kyushu island of Japan and is known as a volcano-tectonic depression region. The area is characterized by its potential geothermal resources. In this study, we attempt to delineate the subsurface structures... more
Hohi area is located in central Kyushu island of Japan and is known as a volcano-tectonic depression region. The area is characterized by its potential geothermal resources. In this study, we attempt to delineate the subsurface structures of the area using integrated interpretation of existing gravity data. The gravity survey of Hohi area is about 500 km 2 . The total number of gravity stations was up to 1500 and average distribution of stations was approximately 3 per km 2 . Interpretation of horizontal gradient of the gravity data indicated that the area is characterized by the existence of high gradient anomalies associated with existing geothermal fields and manifestations. Horizontal gradient analysis also enabled tracing several faults that are mainly striking in the S-N, NW-SE, and NE-SW directions. Euler deconvolution method has been applied to the gravity data and provided fast information about both the depth and trends of the shallower subsurface structures in the area. D...
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The Ghawar Anticline (GA) belongs to super-giant Rayn Anticlines in Eastern Saudi Arabia (ESA). The origin of GA is ascribed to basement-uplift, although, its evolution remains obscure due to inadequate knowledge on configuration of... more
The Ghawar Anticline (GA) belongs to super-giant Rayn Anticlines in Eastern Saudi Arabia (ESA). The origin of GA is ascribed to basement-uplift, although, its evolution remains obscure due to inadequate knowledge on configuration of deeper crust and role of crust in producing the basement uplift. The nature of deeper crust is comprehended by an integrated crustal model utilizing DEM, Bouguer anomaly (BA) map, and high-pass-filtered residual BA map by using Laplacian operator, tilt derivative, theta maps, and Euler 3D convolution map on BA data. These maps prove helpful in delineating the structural outline of GA and its edge detection of the uplifted basement against the adjoining sub-basins. 2D gravity inversion for a traverse represents a model on subsurface mass anomalies extending from basement to Moho depth, for which, constraints are utilized based on the nature of seismogenic crust in ESA and available results of receiver function for four seismic stations. A 3-layer source on mass anomalies with depths of 3–5, 22.5, and 40 km is inferred. Poisson’ ratio based on Vp/Vs values is high: 0.41–0.42 on its limbs to 0.44 at its median part, where the receiver function data reveals a zone of mantle uplift. Main results derived from Integrated Gravity Model underlying the traverse are as follows: (i) Moho is uplifted by ~ 9 km below GA, for a 220-km width, (ii) the zone of basement uplift in the top crust is ~ 4.5 km over a distance of ~ 75 km, where deep-penetrative faults assist the basement uplift, and (iii) a higher thermal regime probably influenced the crustal configuration below GA.
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The gravity effect of most geologic structures can be approximated by a continuous function in both depth and model type (shape factor) variables with an amplitude factor related to these buried structures. Interpretation of gravity data... more
The gravity effect of most geologic structures can be approximated by a continuous function in both depth and model type (shape factor) variables with an amplitude factor related to these buried structures. Interpretation of gravity data aims essentially to estimate location, depth ...
KAU Research Repository. Document Details Document Type, : Article In Journal. Document Title, : Analysis and Interpretation of Aeromagnetic Data for East of Nasser Lake Area, Aswan, Egypt. Authors, : Eslam A. Elawadi-Ahmed A.... more
KAU Research Repository. Document Details Document Type, : Article In Journal. Document Title, : Analysis and Interpretation of Aeromagnetic Data for East of Nasser Lake Area, Aswan, Egypt. Authors, : Eslam A. Elawadi-Ahmed A. Nigm-Mamdouh M. El-Tarras-Mahmoud I. Mira ...
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Geoelectrical measurements using the vertical electrical sounding method were conducted on the eastern Gulf of Aqaba (GOA) coast in Jordan. The objectives of the study were (i) to map the Quaternary sediments in areas where little is... more
Geoelectrical measurements using the vertical electrical sounding method were conducted on the eastern Gulf of Aqaba (GOA) coast in Jordan. The objectives of the study were (i) to map the Quaternary sediments in areas where little is known about the subsurface geology ...
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ABSTRACT Geological and structural mappings of Tayyib Al-Ism area were carried out using the rocks finite strain data, the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data and the field based observations. To analyze the finite strain... more
ABSTRACT Geological and structural mappings of Tayyib Al-Ism area were carried out using the rocks finite strain data, the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data and the field based observations. To analyze the finite strain in the studied rocks, the Rf /ϕ and Fry methods are applied to feldspar porphyroclasts and mafic grains from nine metavolcano-sedimentary samples (Hegaf Formation), four diorite-gabbros suite samples (Sawawin Complex), two meta-granite samples (Ifal suite) and five Zuhd alkali granite samples. The obtained data indicate traces of high to moderate level of deformation in the meta-granite and metavolcano-sedimentary rocks. The axial ratios along the XZ section range from 1.70 to 4.80 for the Rf/ϕ method and from 1.50 to 4.50 for the Fry method. A sub-vertical trend of short axes in association with sub-horizontal foliation is also observed. These informations allow us to conclude that a finite strain in the deformed granitic rocks is of the same order of magnitude as in the metavolcano-sedimentary rocks. The contacts between the metavolcano-sedimentary and granitic rocks in Tayyib al Ism area were formed during the granitic intrusions along some of the faults under brittle to semi-ductile deformation conditions. These faults have significantly influenced the geometry and style of rifting in the Red Sea during the Neogene. The finite strain was accumulated in the area during the process of deformation, which superimpose the already existed nappe structure. It indicates that the nappe contacts formed during the accumulation of finite strain. In addition to finite strain analysis, band ratio images (3/1, 5/3, 7/5) and Principal Component Analysis (PCA) technique have been used, which proved effective in mapping geological and structural features of various rock bodies exposed in the study area
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Aeromagnetic imaging of Wadi Natash volcanics, South Eastern Desert, Egypt. Eslam A. Elawadi and Atef A. Ismail. Airborne Geophysics Department, Nuclear Materials Authority of Egypt. ABSTRACT. Magnetic survey is an efficient ...
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Egyptian geologists have interpreted the depression to be a fault graben in the Esna area (RIGW, 1994). The bedrock walls of the graben are comprised of Cretaceous to Eocene marine shales, carbonate and sandstone. In the present, the... more
Egyptian geologists have interpreted the depression to be a fault graben in the Esna area (RIGW, 1994). The bedrock walls of the graben are comprised of Cretaceous to Eocene marine shales, carbonate and sandstone. In the present, the integration of the results obtained through the previous geological and geoelectric sounding as well as remote sensing data, and aeromagnetic data used to establish the common surface and subsurface characteristic features of the study area. The ETM image processing techniques used to extract the structural lineaments to determine the structural pattern at the investigated area. The rose diagram shows that the predominant structural trend affecting the area, is ENE-WSW direction. The zones of high structural lineament intensities are concentrated at the southwestern and the northeastern part of prospect area. The available vertical electrical soundings were conducted to define the depth of bed rock and its configuration. The average depth surface of bas...
ABSTRACT Dipolar aeromagnetic anomalies of the Quseir area and its extension to the offshore Red Sea have been interpreted to have a strong relation to the thermal sources of the Red Sea geothermal system. This interpretation is supported... more
ABSTRACT Dipolar aeromagnetic anomalies of the Quseir area and its extension to the offshore Red Sea have been interpreted to have a strong relation to the thermal sources of the Red Sea geothermal system. This interpretation is supported by field observations, ...