Eslam Elawadi | King Saud University (original) (raw)

Papers by Eslam Elawadi

Research paper thumbnail of Integrated Geophysical Survey for Site Investigation at a New Dwelling Area, Egypt

Journal of Environmental and Engineering Geophysics, 2006

An integrated geophysical survey was carried out in a new dwelling area at 15-May town, southeast... 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...

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Research paper thumbnail of Exploration Geophysics

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Research paper thumbnail of Seismicity analysis and machine learning models for short-term low magnitude seismic activity predictions in Cyprus

Soil Dynamics and Earthquake Engineering, 2020

Abstract Effective management and planning for the sustainable development of urban regions requi... 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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Research paper thumbnail of Pulsed emplacement under the Uyaijah granite ring structure, eastern Saudi Arabia—results from 3D gravity-magnetic inversion

Arabian Journal of Geosciences, 2021

The Uyaijah ring structure (URS), situated within the Precambrian Kushaymiyah Igneous Complex (KI... 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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Research paper thumbnail of Induced and Ambient Crustal Seismicity under the Ghawar Oil-Gas Fields, Saudi Arabia

Journal of the Geological Society of India, 2018

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Research paper thumbnail of Interpretation of Isolated Gravity Anomalies Using Euler Deconvolution

64th EAGE Conference & Exhibition, 2002

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Research paper thumbnail of Mapping surface geology using airborne gamma-ray spectrometric survey data-A case study

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Research paper thumbnail of Flooding risk analysis of the central part of western Saudi Arabia using remote sensing data

saudigis.org

Western Saudi Arabia is one of the arid areas which occasionally subjected to flash flooding effe... 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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Research paper thumbnail of Southwest of Saudi Arabia

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Research paper thumbnail of Aquifer boundaries explored by geoelectrical measurements in the Red Sea coastal plain of Jazan area, Southwest Saudi Arabia

academicjournals.org

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Research paper thumbnail of Groundwater exploration using geoelectrical resistivity technique at Al-Quwy’yia area central Saudi Arabia

Geoelectrical resistivity surveys were carried out in Al Quwy’yia area, located at the centeral p... 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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Research paper thumbnail of Detection of cavities and tunnels from gravity data using a neural network

Exploration Geophysics, 2001

We have developed a simple approach to determine the depth and radius of subsurface cavities from... 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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Research paper thumbnail of Subsurface Structural Mapping Using Gravity Data of Hohi Geothermal Area, Central Kyushu, Japan

Hohi area is located in central Kyushu island of Japan and is known as a volcano-tectonic depress... 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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Research paper thumbnail of A Quantitative Site-Specific Classification Approach Based on Affinity Propagation Clustering

IEEE Access

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Research paper thumbnail of Geophysical studies for the aquifer properties along Wadi Nu’man, Holy Makkah area, Saudi Arabia

Arabian Journal of Geosciences

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Research paper thumbnail of Crustal control on basement uplift beneath the Ghawar Anticline, Saudi Arabia—gravity modeling with receiver function constraints

Arabian Journal of Geosciences

The Ghawar Anticline (GA) belongs to super-giant Rayn Anticlines in Eastern Saudi Arabia (ESA). T... 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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Research paper thumbnail of Cinder cone morphometry in relation to gravity anomaly zones in the Harrat al Birk and Asir foreland, SW Saudi Arabia

Journal of Earth System Science

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Research paper thumbnail of Estimation of shape factor of buried structure from residual gravity anomaly data

faculty.ksu.edu.sa

The gravity effect of most geologic structures can be approximated by a continuous function in bo... 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 ...

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Research paper thumbnail of Analysis and Interpretation of Aeromagnetic Data for East of Nasser Lake Area, Aswan, Egypt

Earth Sciences, 2009

KAU Research Repository. Document Details Document Type, : Article In Journal. Document Title, : ... 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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Research paper thumbnail of Crustal structure beneath the volcanic field in the Tihamat Plains, Saudi Arabia: An integrated model constrained by gravity modelling and receiver function results

Journal of Asian Earth Sciences

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Research paper thumbnail of Integrated Geophysical Survey for Site Investigation at a New Dwelling Area, Egypt

Journal of Environmental and Engineering Geophysics, 2006

An integrated geophysical survey was carried out in a new dwelling area at 15-May town, southeast... 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...

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Research paper thumbnail of Exploration Geophysics

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Research paper thumbnail of Seismicity analysis and machine learning models for short-term low magnitude seismic activity predictions in Cyprus

Soil Dynamics and Earthquake Engineering, 2020

Abstract Effective management and planning for the sustainable development of urban regions requi... 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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Research paper thumbnail of Pulsed emplacement under the Uyaijah granite ring structure, eastern Saudi Arabia—results from 3D gravity-magnetic inversion

Arabian Journal of Geosciences, 2021

The Uyaijah ring structure (URS), situated within the Precambrian Kushaymiyah Igneous Complex (KI... 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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Research paper thumbnail of Induced and Ambient Crustal Seismicity under the Ghawar Oil-Gas Fields, Saudi Arabia

Journal of the Geological Society of India, 2018

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Research paper thumbnail of Interpretation of Isolated Gravity Anomalies Using Euler Deconvolution

64th EAGE Conference & Exhibition, 2002

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Mapping surface geology using airborne gamma-ray spectrometric survey data-A case study

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Flooding risk analysis of the central part of western Saudi Arabia using remote sensing data

saudigis.org

Western Saudi Arabia is one of the arid areas which occasionally subjected to flash flooding effe... 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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Research paper thumbnail of Southwest of Saudi Arabia

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Aquifer boundaries explored by geoelectrical measurements in the Red Sea coastal plain of Jazan area, Southwest Saudi Arabia

academicjournals.org

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Groundwater exploration using geoelectrical resistivity technique at Al-Quwy’yia area central Saudi Arabia

Geoelectrical resistivity surveys were carried out in Al Quwy’yia area, located at the centeral p... 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...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Detection of cavities and tunnels from gravity data using a neural network

Exploration Geophysics, 2001

We have developed a simple approach to determine the depth and radius of subsurface cavities from... 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 ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Subsurface Structural Mapping Using Gravity Data of Hohi Geothermal Area, Central Kyushu, Japan

Hohi area is located in central Kyushu island of Japan and is known as a volcano-tectonic depress... 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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Research paper thumbnail of A Quantitative Site-Specific Classification Approach Based on Affinity Propagation Clustering

IEEE Access

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Geophysical studies for the aquifer properties along Wadi Nu’man, Holy Makkah area, Saudi Arabia

Arabian Journal of Geosciences

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Crustal control on basement uplift beneath the Ghawar Anticline, Saudi Arabia—gravity modeling with receiver function constraints

Arabian Journal of Geosciences

The Ghawar Anticline (GA) belongs to super-giant Rayn Anticlines in Eastern Saudi Arabia (ESA). T... 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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Research paper thumbnail of Cinder cone morphometry in relation to gravity anomaly zones in the Harrat al Birk and Asir foreland, SW Saudi Arabia

Journal of Earth System Science

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Research paper thumbnail of Estimation of shape factor of buried structure from residual gravity anomaly data

faculty.ksu.edu.sa

The gravity effect of most geologic structures can be approximated by a continuous function in bo... 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 ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Analysis and Interpretation of Aeromagnetic Data for East of Nasser Lake Area, Aswan, Egypt

Earth Sciences, 2009

KAU Research Repository. Document Details Document Type, : Article In Journal. Document Title, : ... 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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Research paper thumbnail of Crustal structure beneath the volcanic field in the Tihamat Plains, Saudi Arabia: An integrated model constrained by gravity modelling and receiver function results

Journal of Asian Earth Sciences

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