Dr Hesham Mossa | National Research Institute Of Astronomy And Geophysics Nriag (original) (raw)

Papers by Dr Hesham Mossa

Research paper thumbnail of Utilization of Abandoned Oil Well Logs and Seismic Data for Modeling and Assessing Deep Geothermal Energy Resources: A Case Study of the Hammam Faraun Area, Sinai Peninsula, Egypt

Research paper thumbnail of Capsule Neural Network Guided by Compact Convolutional Transformer for Discriminating Earthquakes from Quarry Blasts

Seismological Research Letters

Misclassified nonearthquake seismic events like quarry blasts can contaminate the earthquake cata... more Misclassified nonearthquake seismic events like quarry blasts can contaminate the earthquake catalog. The local earthquakes sometimes have similar features as the quarry blasts, which makes manual discrimination difficult and unreliable. Thus, we propose to use the compact convolutional transformer (CCT) and capsule neural network to discriminate between earthquakes and quarry blasts. First, we extract 60 s three-channel seismograms, that is, 10 and 50 s before and after the P-wave arrival time. Then, we transform the time-series data into a time–frequency domain (scalogram) using the continuous wavelet transform. Afterward, we utilize the CCT network to extract the most significant features from the input scalograms. The capsule neural network is utilized to extract the spatial relation between the extracted features using the routing-by-agreement approach (dynamic routing). The capsule neural network extracts different digit vectors for the earthquake and the quarry blast classes,...

Research paper thumbnail of Site Response Mapping at Pulau Pinang, Malaysia Using the Horizontal-to-Vertical Spectral Ratio Technique and Multichannel Analysis of Surface Waves

Advances in Science, Technology & Innovation/Advances in science, technology & innovation, 2024

Research paper thumbnail of Seismo-Lineaments in Egypt: Analysis and Implications for Active Tectonic Structures and Earthquake Magnitudes

Remote Sensing

Quiescent faults may be capable of creating catastrophic earthquakes in locations with moderate a... more Quiescent faults may be capable of creating catastrophic earthquakes in locations with moderate and/or low seismic activity, such as Egypt. This study combines structural, remote sensing (RS), geophysical, and seismic activity data to examine and analyze the relationship between tectonic structures and seismotectonic activity in Egypt. In a new seismo-lineaments map of Egypt, tectonic lineaments of the Egyptian mainland were delineated and classified. The database contains 8000 lineaments that were divided into distinct geographical zones using statistical analysis and general features. Delineated lineaments were integrated with digitized geological and geophysical surface and subsurface faults and geographic information systems (GIS) processing techniques were applied to produce 4249 faults. The spatial distribution of seismic activity was determined to extract 1968 competent faults out of 4249 capable faults (i.e., greater than 10 km and suitably orientated concerning the existing...

Research paper thumbnail of Discriminating Earthquakes From Quarry Blasts Using Capsule Neural Network

IEEE Geoscience and Remote Sensing Letters

Research paper thumbnail of An Optimized Learning Model Augment Analyst Decisions for Seismic Source Discrimination

IEEE Transactions on Geoscience and Remote Sensing

Research paper thumbnail of Spectral characteristics of P-and S-wave quarry blasts in Aswan region, South Egypt

Journal of African Earth Sciences

Research paper thumbnail of Discrimination between earthquakes and quarry blasts in the Aswan region, southern Egypt using P-wave source spectra

We analyzed 3,069 seismic signals from 413 events (112 explosions and 301 shallow earthquakes, de... more We analyzed 3,069 seismic signals from 413 events (112 explosions and 301 shallow earthquakes, depths

Research paper thumbnail of A review of the Egyptian National Seismological Network after 20 years of operation

NRIAG Journal of Astronomy and Geophysics, 2020

On 12 October 1992, a moderate earthquake with magnitude, Mw 5.8 was occurred in Cairo; the epice... more On 12 October 1992, a moderate earthquake with magnitude, Mw 5.8 was occurred in Cairo; the epicentre is located 25 km south west of Cairo, resulted in great damage in the surrounding area and extended 300 km away from the epicentre. Subsequently, the government established Egyptian National Seismological Network (ENSN) under the supervision of National Research Institute of Astronomy and Geophysics (NRIAG) with 66 stations of different recording bands (e.g. short period, broadband) for monitoring the seismic activity in and around Egypt. The network started operation since mid-1997 up till now, consider revising 20 years of operation, a lot of changes were done (sensors, digitisers, station locations and even stations name), there is still the absence of adequate documentation of the type of changes made. This article is the first attempt to study the recorded data to track all changes done in the network, as a first step towards a different studies regarding determination of the detection capabilities of ENSN's stations and proposed an optimisation solutions for the current faced problems. A software code was designed under Matlab programme to read around 55,000 recorded events and track different changes that took place during the operational time. The output of this study will affect all related research work including magnitude determination and hazard analysis.

Research paper thumbnail of Deterministic scenarios for seismic hazard assessment in Egypt

Journal of African Earth Sciences, 2019

Abstract This study is an extension of the previous works in the field of seismic hazard assessme... more Abstract This study is an extension of the previous works in the field of seismic hazard assessment in Egypt with the aim of making the results more accurate and effective, in view of the worst possible scenarios to assess the seismic hazard. The deterministic seismic hazard approach was applied to assess the hazard in Egypt. An updated earthquake catalog of Egypt was prepared and the aftershocks were screened and removed. All the earthquake sizes were unified to the moment magnitude scale. The earthquake catalog was used to identify and locate, accurately, the possible multi-seismotectonic scenarios in and around Egypt. The controlling earthquake was identified from the effective seismic source. Suitable ground motion equations were used to calculate the hazard from each source. Seismic hazard was calculated from each seismic source with the maximum expected earthquake and the shortest distance (worst scenario) from these sources to specific sites all over Egypt distributed on a grid with 0.45° interval. Hazard maps were produced for the peak ground acceleration and for the 0.1, 0.2, 0.5, 1 and 2 s spectral periods for the 50th (median) percentile level for the selected probabilities of exceedance on bedrock condition for various possible seismotectonic models. Finally, the results obtained from the worst case scenarios were compared with the published probabilistic hazard results to ensure the general level of hazard in Egypt.

Research paper thumbnail of Local site characteristics and earthquake ground motion parameters around the Nile River, south of Cairo, Egypt

Journal of Applied Geophysics, 2021

Parameters related to local site conditions represent an essential information for earthquake haz... more Parameters related to local site conditions represent an essential information for earthquake hazard evaluation and seismic risk mitigation at any region. In this research, the authors determine the local site characteristics and seismic ground motions around the Nile River, south of Cairo City, Egypt. This area suffered from a moderate earthquake (Mw 5.8) on 12 October 1992 and influenced by a soil liquefaction. Furthermore, the area is covered by soft sediments with large thickness, which may amplify seismic waves and lead to more damage in the event of earthquakes occurrence. Microtremor survey was carried out at six liquefiable sites in the study area by array of seismic stations. The recorded data was analyzed by the Centerless Circular Array (CCA) method to infer the shear wave velocity (Vs). The dispersion curves yielded from this analysis cover frequency range from 2.3 to 13.5 Hz. An inversion process was applied to get the Vs profile. The obtained velocities were averaged at 30 m depth (Vs 30) which in turn have been used for a soil classification and for calculating the bearing capacity of soil. The H/V spectral ratio method was used for an experimental estimation of the site predominant frequency and its corresponding amplitude of seismic waves. Moreover, seismic amplification was calculated using the shear wave velocities. The Peak Ground Acceleration (PGA) and seismic intensity (MMI) were calculated for the October 12, 1992, earthquake. The results reveal Vs 30 values from 170 to 240 m/s. Soil Class D is predominant in the study area. The amplification factor ranges from 2.5 to 4.5, corresponding to predominant frequency from 0.5 to 1.4 Hz. The allowable bearing capacity ranges from 0.7 to 1.0 Kg/cm 2. The PGA at the surface ranges from 0.16 to 0.4 g. The calculated seismic intensity (MMI) ranges from VII to VIII which are the same with those observed during the 12 October 1992 earthquake. The parameters estimated in this research may effectively contribute to the earthquake risk reduction in the study area.

Research paper thumbnail of A homogenous moment magnitude and local magnitude scaling relation for earthquakes in Egypt

NRIAG Journal of Astronomy and Geophysics, 2020

Research paper thumbnail of Re-evaluation of Liquefaction Potentiality for Selected Pre-liquefied Sites Associated with the 1992 Cairo Earthquake

Indian Geotechnical Journal, 2017

A moderate earthquake (Ms = 5.8) was occurred on October 12, 1992 at about 25 km south west of Ca... more A moderate earthquake (Ms = 5.8) was occurred on October 12, 1992 at about 25 km south west of Cairo city—Egypt. It caused large damage to numerous poorly constructed buildings. One of the important seismological phenomenon happened during the earthquake is the soil liquefaction which was associated usually with the occurrence of big sand-boils near the epicenter of the earthquake. Recently different methods are used to re-evaluate the liquefaction potentiality, in this study five different sites that showed high liquefaction potentiality during Cairo earthquake, have been selected to be studied to for re-evaluate liquefaction potentiality in Egypt. Shear wave velocity determination provides a promising tool to calculate the factor of safety (FS) against liquefaction, and resistance evaluation of sandy soils against this phenomenon. Multi-channel analysis of surface wave method as an efficient tool and is here used to infer the velocity profile at the considered sites to be used as input for the calculation of FS as an indication for liquefaction potentiality. The aim of this study is to determine the potentiality of liquefaction phenomenon in the selected sites to be one of soil characteristics input for any further hazard study. The selected five sites are named: Aquaz, Atf, Bedsa, El-Gammal, Zaweit Dahshour showed a liquefaction liquation during the 1992 Cairo earthquake which forced us to re-evaluate and update our knowledge through the recent technique about the liquefaction potentiality at these sites. The FS obtained by using shear wave was compared with the values obtained from SPT from previous studies.

Research paper thumbnail of Correction to: The efficiency of horizontal to vertical spectral ratio technique for buried monuments delineation (case study, Saqqara (Zoser) pyramid, Egypt)

Arabian Journal of Geosciences, 2018

Research paper thumbnail of Earthquake ground motion simulation at Zoser pyramid using the stochastic method: A step toward the preservation of an ancient Egyptian heritage

NRIAG Journal of Astronomy and Geophysics, 2017

Strong ground shaking during earthquakes can greatly affect the ancient monuments and subsequentl... more Strong ground shaking during earthquakes can greatly affect the ancient monuments and subsequently demolish the human heritage. On October 12th 1992, a moderate earthquake (Ms = 5.8) shocked the greater Cairo area causing widespread damages. Unfortunately, the focus of that earthquake is located about 14 km to the south of Zoser pyramid. After the earthquake, the Egyptian Supreme council of antiquities issued an alarm that Zoser pyramid is partially collapsed and international and national efforts are exerted to restore this important human heritage that was built about 4000 years ago. Engineering and geophysical work is thus needed for the restoration process. The definition of the strong motion parameters is one of the required studies since seismically active zone is recorded in its near vicinity. The present study adopted the stochastic method to determine the peak ground motion (acceleration, velocity and displacement) for the three largest earthquakes recorded in the Egypt's seismological history. These earthquakes are Shedwan earthquake with magnitude Ms = 6.9, Aqaba earthquake with magnitude Mw = 7.2 and Cairo (Dahshour earthquake) with magnitude Ms = 5.8. The former two major earthquakes took place few hundred kilometers away. It is logic to have the predominant effects from the epicentral location of the Cairo earthquake; however, the authors wanted to test also the long period effects of the large distance earthquakes expected from the other two earthquakes under consideration. In addition, the dynamic site response was studied using the Horizontal to vertical spectral ratio (HVSR) technique. HVSR can provide information about the fundamental frequency successfully; however, the ampli

Research paper thumbnail of Probabilistic seismic hazards assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau

Journal of Geophysics and Engineering, 2017

Research paper thumbnail of Magnitude scales regression for Egyptian seismological network

Arabian Journal of Geosciences, 2015

Your article is protected by copyright and all rights are held exclusively by Saudi Society for G... more Your article is protected by copyright and all rights are held exclusively by Saudi Society for Geosciences. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Research paper thumbnail of Review of the Seismotectonic Setting of the Gulf of Aqaba with Respect to the 27 June 2015 and the 16 May 2016 Earthquake Sequences

Pure and Applied Geophysics, 2018

The Gulf of Aqaba is one of the most active places around Egypt, with several earthquake sequence... more The Gulf of Aqaba is one of the most active places around Egypt, with several earthquake sequences having occurred there through ancient and modern times. In the last century, four earthquake sequences took place in the gulf (1983, 1990, 1993, and 1995). Recently, on 27 June 2015, a sequence of 96 earthquakes with local magnitudes ranging from 0.7 to 5.2 was recorded by the Egyptian National Seismological Network (ENSN). On 16 May 2016, another earthquake sequence started and continued for several consecutive days, with 95 events with local magnitudes ranging from 1.6 to 5.5 being centered south of the 27 June 2015 sequence. In this paper, we analyse the complete waveform and polarity data set of both earthquake sequences to determine their focal mechanisms and to update our knowledge of the stress field in the Gulf of Aqaba. Through the results obtained, we conclude that, the Gulf of Aqaba is affected by a primary structure of a left-lateral strike-slip fault with a minor normal component in most segments. Our study also infers the presence of a secondary structure, which is indicated to be a right-lateral strike-slip with a minor reverse component.

Research paper thumbnail of Probabilistic seismic hazards assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau

Journal of Geophysics and Engineering

Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by c... more Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by common seismological activity; generally an earthquake of moderate magnitude is experienced at an interval of roughly every 20 years, originating mainly from two major sources, either a local source (e.g. Ranau and Lahad Dato) or a regional source (e.g. Kalimantan and South Philippines subductions). The seismicity map of Sabah shows the presence of two zones of distinctive seismicity, these zones are near Ranau (near Kota Kinabalu) and Lahad Datu in the southeast of Sabah. The seismicity record of Ranau begins in 1991, according to the international seismicity bulletins (e.g. United States Geological Survey and the International Seismological Center), and this short record is not sufficient for seismic source characterization. Fortunately, active Quaternary fault systems are delineated in the area. Henceforth, the seismicity of the area is thus determined as line sources referring to these faults. Two main fault systems are believed to be the source of such activities; namely, the Mensaban fault zone and the Crocker fault zone in addition to some other faults in their vicinity. Seismic hazard assessments became a very important and needed study for the extensive developing projects in Sabah especially with the presence of earthquake activities. Probabilistic seismic hazard assessments are adopted for the present work since it can provide the probability of various ground motion levels during expected from future large earthquakes. The output results are presented in terms of spectral acceleration curves and uniform hazard curves for periods of 500, 1000 and 2500 years. Since this is the first time that a complete hazard study has been done for the area, the output will be a base and standard for any future strategic plans in the area.

Research paper thumbnail of Strength and ductility level earthquake design for Gulf of Suez oil platforms

Journal of Seismology

Gulf of Suez area which characterized by a moderate seismic activity is consider as a very import... more Gulf of Suez area which characterized by a moderate seismic activity is consider as a very important area in Egypt. Nearly 75% of the national oil production is covered from this area. Seismic hazard (both probabilistic and deterministic) was carried out to study the possibility of earthquake damage in the area; a new seismic model was used taking into account the seismo-tectonic framework of the region. The hazard calculations utilized at strength and ductility level periods at the whole area of the Gulf of Suez. Fundamentally, the hazard calculations were performed at bedrock conditions, and the spectrum was estimated over the period range of 0.001–12 s. At Abou Zeniama area, where many oil platforms exist, the hazard was calculated at the sea floor, at depth 4.7 m and at depth 26.0 m. The maximum spectral accelerations at strength level earthquakes (SLEs) are found to be 0.260 (g), 0.203 (g), and 0.156 (g) for 90.48% chance, of non-exceedance in 50 years (return period 500 year) at sea floor, at depth 4.7 m and at depth 26 m, respectively. While the ductility level earthquake (DLE) are found to be 0.30 (g), 0.23 (g), and 0.18 (g) for 95.12% chance of non-exceedance in 50 years (return period 1000 year) at sea floor, at depth 4.7 m, and at depth 26 m, respectively. The deterministic hazard calculation was estimated at 50th and 84th percentile levels for the median peak ground acceleration. The study target initiated from the importance of studying the seismic hazard, SLE, and DLE in the area which contain most of the Egyptian oil industry with many off shore platforms.

Research paper thumbnail of Utilization of Abandoned Oil Well Logs and Seismic Data for Modeling and Assessing Deep Geothermal Energy Resources: A Case Study of the Hammam Faraun Area, Sinai Peninsula, Egypt

Research paper thumbnail of Capsule Neural Network Guided by Compact Convolutional Transformer for Discriminating Earthquakes from Quarry Blasts

Seismological Research Letters

Misclassified nonearthquake seismic events like quarry blasts can contaminate the earthquake cata... more Misclassified nonearthquake seismic events like quarry blasts can contaminate the earthquake catalog. The local earthquakes sometimes have similar features as the quarry blasts, which makes manual discrimination difficult and unreliable. Thus, we propose to use the compact convolutional transformer (CCT) and capsule neural network to discriminate between earthquakes and quarry blasts. First, we extract 60 s three-channel seismograms, that is, 10 and 50 s before and after the P-wave arrival time. Then, we transform the time-series data into a time–frequency domain (scalogram) using the continuous wavelet transform. Afterward, we utilize the CCT network to extract the most significant features from the input scalograms. The capsule neural network is utilized to extract the spatial relation between the extracted features using the routing-by-agreement approach (dynamic routing). The capsule neural network extracts different digit vectors for the earthquake and the quarry blast classes,...

Research paper thumbnail of Site Response Mapping at Pulau Pinang, Malaysia Using the Horizontal-to-Vertical Spectral Ratio Technique and Multichannel Analysis of Surface Waves

Advances in Science, Technology & Innovation/Advances in science, technology & innovation, 2024

Research paper thumbnail of Seismo-Lineaments in Egypt: Analysis and Implications for Active Tectonic Structures and Earthquake Magnitudes

Remote Sensing

Quiescent faults may be capable of creating catastrophic earthquakes in locations with moderate a... more Quiescent faults may be capable of creating catastrophic earthquakes in locations with moderate and/or low seismic activity, such as Egypt. This study combines structural, remote sensing (RS), geophysical, and seismic activity data to examine and analyze the relationship between tectonic structures and seismotectonic activity in Egypt. In a new seismo-lineaments map of Egypt, tectonic lineaments of the Egyptian mainland were delineated and classified. The database contains 8000 lineaments that were divided into distinct geographical zones using statistical analysis and general features. Delineated lineaments were integrated with digitized geological and geophysical surface and subsurface faults and geographic information systems (GIS) processing techniques were applied to produce 4249 faults. The spatial distribution of seismic activity was determined to extract 1968 competent faults out of 4249 capable faults (i.e., greater than 10 km and suitably orientated concerning the existing...

Research paper thumbnail of Discriminating Earthquakes From Quarry Blasts Using Capsule Neural Network

IEEE Geoscience and Remote Sensing Letters

Research paper thumbnail of An Optimized Learning Model Augment Analyst Decisions for Seismic Source Discrimination

IEEE Transactions on Geoscience and Remote Sensing

Research paper thumbnail of Spectral characteristics of P-and S-wave quarry blasts in Aswan region, South Egypt

Journal of African Earth Sciences

Research paper thumbnail of Discrimination between earthquakes and quarry blasts in the Aswan region, southern Egypt using P-wave source spectra

We analyzed 3,069 seismic signals from 413 events (112 explosions and 301 shallow earthquakes, de... more We analyzed 3,069 seismic signals from 413 events (112 explosions and 301 shallow earthquakes, depths

Research paper thumbnail of A review of the Egyptian National Seismological Network after 20 years of operation

NRIAG Journal of Astronomy and Geophysics, 2020

On 12 October 1992, a moderate earthquake with magnitude, Mw 5.8 was occurred in Cairo; the epice... more On 12 October 1992, a moderate earthquake with magnitude, Mw 5.8 was occurred in Cairo; the epicentre is located 25 km south west of Cairo, resulted in great damage in the surrounding area and extended 300 km away from the epicentre. Subsequently, the government established Egyptian National Seismological Network (ENSN) under the supervision of National Research Institute of Astronomy and Geophysics (NRIAG) with 66 stations of different recording bands (e.g. short period, broadband) for monitoring the seismic activity in and around Egypt. The network started operation since mid-1997 up till now, consider revising 20 years of operation, a lot of changes were done (sensors, digitisers, station locations and even stations name), there is still the absence of adequate documentation of the type of changes made. This article is the first attempt to study the recorded data to track all changes done in the network, as a first step towards a different studies regarding determination of the detection capabilities of ENSN's stations and proposed an optimisation solutions for the current faced problems. A software code was designed under Matlab programme to read around 55,000 recorded events and track different changes that took place during the operational time. The output of this study will affect all related research work including magnitude determination and hazard analysis.

Research paper thumbnail of Deterministic scenarios for seismic hazard assessment in Egypt

Journal of African Earth Sciences, 2019

Abstract This study is an extension of the previous works in the field of seismic hazard assessme... more Abstract This study is an extension of the previous works in the field of seismic hazard assessment in Egypt with the aim of making the results more accurate and effective, in view of the worst possible scenarios to assess the seismic hazard. The deterministic seismic hazard approach was applied to assess the hazard in Egypt. An updated earthquake catalog of Egypt was prepared and the aftershocks were screened and removed. All the earthquake sizes were unified to the moment magnitude scale. The earthquake catalog was used to identify and locate, accurately, the possible multi-seismotectonic scenarios in and around Egypt. The controlling earthquake was identified from the effective seismic source. Suitable ground motion equations were used to calculate the hazard from each source. Seismic hazard was calculated from each seismic source with the maximum expected earthquake and the shortest distance (worst scenario) from these sources to specific sites all over Egypt distributed on a grid with 0.45° interval. Hazard maps were produced for the peak ground acceleration and for the 0.1, 0.2, 0.5, 1 and 2 s spectral periods for the 50th (median) percentile level for the selected probabilities of exceedance on bedrock condition for various possible seismotectonic models. Finally, the results obtained from the worst case scenarios were compared with the published probabilistic hazard results to ensure the general level of hazard in Egypt.

Research paper thumbnail of Local site characteristics and earthquake ground motion parameters around the Nile River, south of Cairo, Egypt

Journal of Applied Geophysics, 2021

Parameters related to local site conditions represent an essential information for earthquake haz... more Parameters related to local site conditions represent an essential information for earthquake hazard evaluation and seismic risk mitigation at any region. In this research, the authors determine the local site characteristics and seismic ground motions around the Nile River, south of Cairo City, Egypt. This area suffered from a moderate earthquake (Mw 5.8) on 12 October 1992 and influenced by a soil liquefaction. Furthermore, the area is covered by soft sediments with large thickness, which may amplify seismic waves and lead to more damage in the event of earthquakes occurrence. Microtremor survey was carried out at six liquefiable sites in the study area by array of seismic stations. The recorded data was analyzed by the Centerless Circular Array (CCA) method to infer the shear wave velocity (Vs). The dispersion curves yielded from this analysis cover frequency range from 2.3 to 13.5 Hz. An inversion process was applied to get the Vs profile. The obtained velocities were averaged at 30 m depth (Vs 30) which in turn have been used for a soil classification and for calculating the bearing capacity of soil. The H/V spectral ratio method was used for an experimental estimation of the site predominant frequency and its corresponding amplitude of seismic waves. Moreover, seismic amplification was calculated using the shear wave velocities. The Peak Ground Acceleration (PGA) and seismic intensity (MMI) were calculated for the October 12, 1992, earthquake. The results reveal Vs 30 values from 170 to 240 m/s. Soil Class D is predominant in the study area. The amplification factor ranges from 2.5 to 4.5, corresponding to predominant frequency from 0.5 to 1.4 Hz. The allowable bearing capacity ranges from 0.7 to 1.0 Kg/cm 2. The PGA at the surface ranges from 0.16 to 0.4 g. The calculated seismic intensity (MMI) ranges from VII to VIII which are the same with those observed during the 12 October 1992 earthquake. The parameters estimated in this research may effectively contribute to the earthquake risk reduction in the study area.

Research paper thumbnail of A homogenous moment magnitude and local magnitude scaling relation for earthquakes in Egypt

NRIAG Journal of Astronomy and Geophysics, 2020

Research paper thumbnail of Re-evaluation of Liquefaction Potentiality for Selected Pre-liquefied Sites Associated with the 1992 Cairo Earthquake

Indian Geotechnical Journal, 2017

A moderate earthquake (Ms = 5.8) was occurred on October 12, 1992 at about 25 km south west of Ca... more A moderate earthquake (Ms = 5.8) was occurred on October 12, 1992 at about 25 km south west of Cairo city—Egypt. It caused large damage to numerous poorly constructed buildings. One of the important seismological phenomenon happened during the earthquake is the soil liquefaction which was associated usually with the occurrence of big sand-boils near the epicenter of the earthquake. Recently different methods are used to re-evaluate the liquefaction potentiality, in this study five different sites that showed high liquefaction potentiality during Cairo earthquake, have been selected to be studied to for re-evaluate liquefaction potentiality in Egypt. Shear wave velocity determination provides a promising tool to calculate the factor of safety (FS) against liquefaction, and resistance evaluation of sandy soils against this phenomenon. Multi-channel analysis of surface wave method as an efficient tool and is here used to infer the velocity profile at the considered sites to be used as input for the calculation of FS as an indication for liquefaction potentiality. The aim of this study is to determine the potentiality of liquefaction phenomenon in the selected sites to be one of soil characteristics input for any further hazard study. The selected five sites are named: Aquaz, Atf, Bedsa, El-Gammal, Zaweit Dahshour showed a liquefaction liquation during the 1992 Cairo earthquake which forced us to re-evaluate and update our knowledge through the recent technique about the liquefaction potentiality at these sites. The FS obtained by using shear wave was compared with the values obtained from SPT from previous studies.

Research paper thumbnail of Correction to: The efficiency of horizontal to vertical spectral ratio technique for buried monuments delineation (case study, Saqqara (Zoser) pyramid, Egypt)

Arabian Journal of Geosciences, 2018

Research paper thumbnail of Earthquake ground motion simulation at Zoser pyramid using the stochastic method: A step toward the preservation of an ancient Egyptian heritage

NRIAG Journal of Astronomy and Geophysics, 2017

Strong ground shaking during earthquakes can greatly affect the ancient monuments and subsequentl... more Strong ground shaking during earthquakes can greatly affect the ancient monuments and subsequently demolish the human heritage. On October 12th 1992, a moderate earthquake (Ms = 5.8) shocked the greater Cairo area causing widespread damages. Unfortunately, the focus of that earthquake is located about 14 km to the south of Zoser pyramid. After the earthquake, the Egyptian Supreme council of antiquities issued an alarm that Zoser pyramid is partially collapsed and international and national efforts are exerted to restore this important human heritage that was built about 4000 years ago. Engineering and geophysical work is thus needed for the restoration process. The definition of the strong motion parameters is one of the required studies since seismically active zone is recorded in its near vicinity. The present study adopted the stochastic method to determine the peak ground motion (acceleration, velocity and displacement) for the three largest earthquakes recorded in the Egypt's seismological history. These earthquakes are Shedwan earthquake with magnitude Ms = 6.9, Aqaba earthquake with magnitude Mw = 7.2 and Cairo (Dahshour earthquake) with magnitude Ms = 5.8. The former two major earthquakes took place few hundred kilometers away. It is logic to have the predominant effects from the epicentral location of the Cairo earthquake; however, the authors wanted to test also the long period effects of the large distance earthquakes expected from the other two earthquakes under consideration. In addition, the dynamic site response was studied using the Horizontal to vertical spectral ratio (HVSR) technique. HVSR can provide information about the fundamental frequency successfully; however, the ampli

Research paper thumbnail of Probabilistic seismic hazards assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau

Journal of Geophysics and Engineering, 2017

Research paper thumbnail of Magnitude scales regression for Egyptian seismological network

Arabian Journal of Geosciences, 2015

Your article is protected by copyright and all rights are held exclusively by Saudi Society for G... more Your article is protected by copyright and all rights are held exclusively by Saudi Society for Geosciences. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Research paper thumbnail of Review of the Seismotectonic Setting of the Gulf of Aqaba with Respect to the 27 June 2015 and the 16 May 2016 Earthquake Sequences

Pure and Applied Geophysics, 2018

The Gulf of Aqaba is one of the most active places around Egypt, with several earthquake sequence... more The Gulf of Aqaba is one of the most active places around Egypt, with several earthquake sequences having occurred there through ancient and modern times. In the last century, four earthquake sequences took place in the gulf (1983, 1990, 1993, and 1995). Recently, on 27 June 2015, a sequence of 96 earthquakes with local magnitudes ranging from 0.7 to 5.2 was recorded by the Egyptian National Seismological Network (ENSN). On 16 May 2016, another earthquake sequence started and continued for several consecutive days, with 95 events with local magnitudes ranging from 1.6 to 5.5 being centered south of the 27 June 2015 sequence. In this paper, we analyse the complete waveform and polarity data set of both earthquake sequences to determine their focal mechanisms and to update our knowledge of the stress field in the Gulf of Aqaba. Through the results obtained, we conclude that, the Gulf of Aqaba is affected by a primary structure of a left-lateral strike-slip fault with a minor normal component in most segments. Our study also infers the presence of a secondary structure, which is indicated to be a right-lateral strike-slip with a minor reverse component.

Research paper thumbnail of Probabilistic seismic hazards assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau

Journal of Geophysics and Engineering

Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by c... more Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by common seismological activity; generally an earthquake of moderate magnitude is experienced at an interval of roughly every 20 years, originating mainly from two major sources, either a local source (e.g. Ranau and Lahad Dato) or a regional source (e.g. Kalimantan and South Philippines subductions). The seismicity map of Sabah shows the presence of two zones of distinctive seismicity, these zones are near Ranau (near Kota Kinabalu) and Lahad Datu in the southeast of Sabah. The seismicity record of Ranau begins in 1991, according to the international seismicity bulletins (e.g. United States Geological Survey and the International Seismological Center), and this short record is not sufficient for seismic source characterization. Fortunately, active Quaternary fault systems are delineated in the area. Henceforth, the seismicity of the area is thus determined as line sources referring to these faults. Two main fault systems are believed to be the source of such activities; namely, the Mensaban fault zone and the Crocker fault zone in addition to some other faults in their vicinity. Seismic hazard assessments became a very important and needed study for the extensive developing projects in Sabah especially with the presence of earthquake activities. Probabilistic seismic hazard assessments are adopted for the present work since it can provide the probability of various ground motion levels during expected from future large earthquakes. The output results are presented in terms of spectral acceleration curves and uniform hazard curves for periods of 500, 1000 and 2500 years. Since this is the first time that a complete hazard study has been done for the area, the output will be a base and standard for any future strategic plans in the area.

Research paper thumbnail of Strength and ductility level earthquake design for Gulf of Suez oil platforms

Journal of Seismology

Gulf of Suez area which characterized by a moderate seismic activity is consider as a very import... more Gulf of Suez area which characterized by a moderate seismic activity is consider as a very important area in Egypt. Nearly 75% of the national oil production is covered from this area. Seismic hazard (both probabilistic and deterministic) was carried out to study the possibility of earthquake damage in the area; a new seismic model was used taking into account the seismo-tectonic framework of the region. The hazard calculations utilized at strength and ductility level periods at the whole area of the Gulf of Suez. Fundamentally, the hazard calculations were performed at bedrock conditions, and the spectrum was estimated over the period range of 0.001–12 s. At Abou Zeniama area, where many oil platforms exist, the hazard was calculated at the sea floor, at depth 4.7 m and at depth 26.0 m. The maximum spectral accelerations at strength level earthquakes (SLEs) are found to be 0.260 (g), 0.203 (g), and 0.156 (g) for 90.48% chance, of non-exceedance in 50 years (return period 500 year) at sea floor, at depth 4.7 m and at depth 26 m, respectively. While the ductility level earthquake (DLE) are found to be 0.30 (g), 0.23 (g), and 0.18 (g) for 95.12% chance of non-exceedance in 50 years (return period 1000 year) at sea floor, at depth 4.7 m, and at depth 26 m, respectively. The deterministic hazard calculation was estimated at 50th and 84th percentile levels for the median peak ground acceleration. The study target initiated from the importance of studying the seismic hazard, SLE, and DLE in the area which contain most of the Egyptian oil industry with many off shore platforms.