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Delineation and characterization of a new seismic source model for seismic hazard studies in Egypt

Research Abstract

In the present study, a new seismic source model for the Egyptian territory and its surroundings is proposed. This model can be readily used for seismic hazard assessment and seismic forecasting studies. Seismicity data, focal mechanism solutions, as well as all available geological and tectonic information (e.g. active faults) were taken into account during the definition of this model, in an attempt to define zones which do not show only a rather homogeneous seismicity release, but also exhibit similar seismotectonic characteristics. This work presents a comprehensive description of the different tectonic features and their associated seismicity to define the possible seismic sources in and around Egypt. The
proposed seismic source model comprises 28 seismic sources covering the shallow seismicity for the Egyptian territory and its surroundings. In addition, for the Eastern Mediterranean region, we considered the shallow seismic source zones, used in the SHARE project for estimating the seismic hazard for Europe. Furthermore, to cover the intermediate-depth seismicity, seven intermediate seismic source zones were delineated in the Eastern Mediterranean region.
Following the determination of zone boundaries, a separate earthquake and focal mechanism sub-catalogue for each seismic zone was created. Seismicity parameters (b-value, activity ‘‘a-value’’ and maximum expected magnitude) have been computed for each source. In addition, the predominant focal mechanism solution was assigned for each source zone using the stress field inversion approach. The proposed seismic source model and its related seismicity parameters can be employed directly in seismic hazard assessment studies for Egypt.

Research Authors
Sawires, R, Pela´ez, J.A., Ibrahim, H.A., Fat-Helbary, R.E., Henares, J., Hamdache, M.
Research Department
Research Journal
Natural Hazards
Research Member
Research Pages
1823-1864
Research Publisher
Springer Science+Business Media Dordrecht 2015
Research Rank
1
Research Vol
80
Research Website
https://link.springer.com/article/10.1007/s11069-015-2034-x
Research Year
2016

Delineation and characterization of a new seismic source model for seismic hazard studies in Egypt

Research Abstract

In the present study, a new seismic source model for the Egyptian territory and its surroundings is proposed. This model can be readily used for seismic hazard assessment and seismic forecasting studies. Seismicity data, focal mechanism solutions, as well as all available geological and tectonic information (e.g. active faults) were taken into account during the definition of this model, in an attempt to define zones which do not show only a rather homogeneous seismicity release, but also exhibit similar seismotectonic characteristics. This work presents a comprehensive description of the different tectonic features and their associated seismicity to define the possible seismic sources in and around Egypt. The
proposed seismic source model comprises 28 seismic sources covering the shallow seismicity for the Egyptian territory and its surroundings. In addition, for the Eastern Mediterranean region, we considered the shallow seismic source zones, used in the SHARE project for estimating the seismic hazard for Europe. Furthermore, to cover the intermediate-depth seismicity, seven intermediate seismic source zones were delineated in the Eastern Mediterranean region.
Following the determination of zone boundaries, a separate earthquake and focal mechanism sub-catalogue for each seismic zone was created. Seismicity parameters (b-value, activity ‘‘a-value’’ and maximum expected magnitude) have been computed for each source. In addition, the predominant focal mechanism solution was assigned for each source zone using the stress field inversion approach. The proposed seismic source model and its related seismicity parameters can be employed directly in seismic hazard assessment studies for Egypt.

Research Authors
Sawires, R, Pela´ez, J.A., Ibrahim, H.A., Fat-Helbary, R.E., Henares, J., Hamdache, M.
Research Department
Research Journal
Natural Hazards
Research Member
Research Pages
1823-1864
Research Publisher
Springer Science+Business Media Dordrecht 2015
Research Rank
1
Research Vol
80
Research Website
https://link.springer.com/article/10.1007/s11069-015-2034-x
Research Year
2016

An earthquake catalogue (2200 B.C. to 2013) for seismotectonic and seismic hazard assessment studies in Egypt

Research Abstract

Of all natural hazards, earthquakes are those which historically have caused the most extensive impact and disruption in terms of damage to infrastructure, human-casualties and economic losses. They are the expression of a continuing evolution of the Earth Planet and a reshaping of the Earth’s surface. They are the most deadly of all natural disasters affecting the human environment. Every year more than one million earthquakes shake different regions of the world, some so feeling and gentle that only the most sensitive instruments can detect the motion,
and others so violent that whole communities are shattered and large sections of terrain are shifted in this process that can start landslides, block rivers, causefloods, and set massive sea waves surging across the oceans.
The amount of damage and number of fatalities at a certain location caused by an earthquake depends on various factors: the magnitude and characteristics of the earthquake focus, distance from the epicenter, soil characteristics, density of buildings and population, and structural design of buildings and infrastructures, among others. These facts are playing an important role in decreasing or increasing the number of victims in recent earthquakes, especially in the developing countries. The increasing population in the earthquake-prone cities, poor construction quality
and lack of building code enforcement are major reasons why the vulnerability due to earthquake is also increasing.

Research Authors
Sawires, R., Peláez, J.A., Fat-Helbary, R.E., Ibrahim, H.A.
Research Department
Research Journal
S. D’Amico (ed.),Earthquakes and Their Impact on Society,
Springer Natural Hazards, DOI 10.1007/978-3-319-21753-6_4
Research Member
Research Pages
97-136
Research Publisher
Springer International Publishing Switzerland 2016
Research Rank
1
Research Vol
NULL
Research Website
https://link.springer.com/chapter/10.1007/978-3-319-21753-6_4
Research Year
2016

An earthquake catalogue (2200 B.C. to 2013) for seismotectonic and seismic hazard assessment studies in Egypt

Research Abstract

Of all natural hazards, earthquakes are those which historically have caused the most extensive impact and disruption in terms of damage to infrastructure, human-casualties and economic losses. They are the expression of a continuing evolution of the Earth Planet and a reshaping of the Earth’s surface. They are the most deadly of all natural disasters affecting the human environment. Every year more than one million earthquakes shake different regions of the world, some so feeling and gentle that only the most sensitive instruments can detect the motion,
and others so violent that whole communities are shattered and large sections of terrain are shifted in this process that can start landslides, block rivers, causefloods, and set massive sea waves surging across the oceans.
The amount of damage and number of fatalities at a certain location caused by an earthquake depends on various factors: the magnitude and characteristics of the earthquake focus, distance from the epicenter, soil characteristics, density of buildings and population, and structural design of buildings and infrastructures, among others. These facts are playing an important role in decreasing or increasing the number of victims in recent earthquakes, especially in the developing countries. The increasing population in the earthquake-prone cities, poor construction quality
and lack of building code enforcement are major reasons why the vulnerability due to earthquake is also increasing.

Research Authors
Sawires, R., Peláez, J.A., Fat-Helbary, R.E., Ibrahim, H.A.
Research Department
Research Journal
S. D’Amico (ed.),Earthquakes and Their Impact on Society,
Springer Natural Hazards, DOI 10.1007/978-3-319-21753-6_4
Research Member
Research Pages
97-136
Research Publisher
Springer International Publishing Switzerland 2016
Research Rank
1
Research Vol
NULL
Research Website
https://link.springer.com/chapter/10.1007/978-3-319-21753-6_4
Research Year
2016

Forecasting moderate earthquakes in Northern Algeria and Morocco

Research Abstract

The studied region, in the northern border of the African Plate, has suffered moderate to strong earthquakes in the last decades. Among them, the September 9, 1954, and the October 10, 1980, El Asnam (formerly known as Orléansville), Algeria, earthquakes, with magnitudes MS6.7 and 7.3, respectively, the February 29, 1960, Agadir, Morocco, M*6.0 earthquake, or the most recent May 21, 2003, Zemmouri-Algiers, Algeria, MW6.8 earthquake. The 1954, 1980 and 2003 Algerian earthquakes caused a large loss of lives (1200, 5000–20,000, according to different estimates, and 2300 people killed, respectively), as well as the 1960 Moroccan earthquake (*12,000 people killed).
In all cases, there were a myriad of injured people, left homeless and heavily damaged and destroyed homes due to structural inadequacies of the buildings. Moreover, critical facilities as hospitals or schools were damaged or destroyed in all quoted earthquakes. Only during the 2003 Algerian earthquake, 130 schools suffered extensive to complete damage in the Algiers region (Bendimerad2004). Apart from these large earthquakes, a large amount of small to moderate earthquakes has been also recorded in this area. A review can be read in the works by Peláez et al. (2007) and Hamdache et al. (2010).

Research Authors
Peláez, J.A., Hamdache, M., Sanz de Galdeano, C., Sawires, R., and García Hernández, M.T.
Research Department
Research Journal
S. D’Amico (ed.),Earthquakes and Their Impact on Society,
Springer Natural Hazards, DOI 10.1007/978-3-319-21753-6_3
Research Member
Research Pages
81-95
Research Publisher
Springer International Publishing Switzerland 2016
Research Rank
1
Research Vol
NULL
Research Website
https://link.springer.com/chapter/10.1007/978-3-319-21753-6_3
Research Year
2016

Probabilistic Seismic Hazard Deaggregation for Selected Egyptian Cities

Research Abstract

A probabilistic seismic hazard analysis in terms of
peak ground acceleration (PGA) and spectral acceleration (SA) values has been performed for the Egyptian territory. Eighty-eight potential seismic sources (for shallow- and intermediate-depth seismicity) in and around Egypt were identified and characterized based on an updated and unified earthquake catalog spanning the time period from 2200 B.C. until 2013 A.D. A logic-tree approach was followed, after a sensitivity analysis, to consider the epistemic uncertainty in the different input parameters, including the selected ground-motion attenuation models to predict the ground motion for the different tectonic environments. Then the seismic hazard deaggregation results, in terms of distance and magnitude, for the
most important cities in Egypt have been computed to help
understanding the relative contributions of the different seismic sources. Seismic hazard deaggregation, in particular, was computed for PGA and SA at periods of 0.2, 1.0 and 2.0 s for rock-site conditions, and for 10% probability of exceedance in 50 years. In general, the results at most of the cities indicate that the distance to
the seismic sources which mostly contribute to the seismic hazard is mainly controlled by the nearby seismic sources (especially for PGA). However, distant events contribute more to the hazard for larger spectral periods (for 1.0 and 2.0 s). A significant result of this type of work is that seismic hazard deaggregation provides useful data on the distance and magnitude of the contributing seismic sources to the hazard in a certain place, which can be applied to generate scenario earthquakes and select acceleration
records for seismic design.

Research Authors
Sawires, R., Peláez, J.A., Fat-Helbary, R.E., Panzera, F., Ibrahim, H.A., and Hamdache M.
Research Department
Research Journal
Pure and Applied Geophysics
Research Member
Research Pages
DOI 10.1007/s00024-017-1490-5
Research Publisher
Springer International Publishing
Research Rank
1
Research Vol
NULL
Research Website
https://link.springer.com/article/10.1007/s00024-017-1490-5
Research Year
2017

Probabilistic Seismic Hazard Deaggregation for Selected Egyptian Cities

Research Abstract

A probabilistic seismic hazard analysis in terms of
peak ground acceleration (PGA) and spectral acceleration (SA) values has been performed for the Egyptian territory. Eighty-eight potential seismic sources (for shallow- and intermediate-depth seismicity) in and around Egypt were identified and characterized based on an updated and unified earthquake catalog spanning the time period from 2200 B.C. until 2013 A.D. A logic-tree approach was followed, after a sensitivity analysis, to consider the epistemic uncertainty in the different input parameters, including the selected ground-motion attenuation models to predict the ground motion for the different tectonic environments. Then the seismic hazard deaggregation results, in terms of distance and magnitude, for the
most important cities in Egypt have been computed to help
understanding the relative contributions of the different seismic sources. Seismic hazard deaggregation, in particular, was computed for PGA and SA at periods of 0.2, 1.0 and 2.0 s for rock-site conditions, and for 10% probability of exceedance in 50 years. In general, the results at most of the cities indicate that the distance to
the seismic sources which mostly contribute to the seismic hazard is mainly controlled by the nearby seismic sources (especially for PGA). However, distant events contribute more to the hazard for larger spectral periods (for 1.0 and 2.0 s). A significant result of this type of work is that seismic hazard deaggregation provides useful data on the distance and magnitude of the contributing seismic sources to the hazard in a certain place, which can be applied to generate scenario earthquakes and select acceleration
records for seismic design.

Research Authors
Sawires, R., Peláez, J.A., Fat-Helbary, R.E., Panzera, F., Ibrahim, H.A., and Hamdache M.
Research Department
Research Journal
Pure and Applied Geophysics
Research Member
Research Pages
DOI 10.1007/s00024-017-1490-5
Research Publisher
Springer International Publishing
Research Rank
1
Research Vol
NULL
Research Website
https://link.springer.com/article/10.1007/s00024-017-1490-5
Research Year
2017

An updated and unified earthquake catalog from 1787 to 2018 for seismic hazard assessment studies in Mexico

Research Abstract

Here we present a new updated and unified Poissonian earthquake catalog for Mexico. The details about the catalog compilation, the removal of duplicate events, unifying the magnitude scales, removal of dependent events through the declustering process and its completeness analysis are presented. Earthquake and focal mechanism data have been compiled from various local, regional and international sources. Large earthquake events (MW ≥ 6.5) have been carefully revised for their epicentral locations and magnitudes from trusted publications. Different magnitude-conversion relationships, compatible with available local and regional ones, has been established to obtain unified moment magnitude estimates for the whole catalog. Completeness periods for the declustered catalog were estimated for the definition of appropriate seismic source models for the whole territory. The final unified Poissonian earthquake catalog spans from 1787 to 2018, covering a spatial extent of 13° to 33°N and 91° to 117°W. This catalog is compatible with other published catalogs providing basis for new analysis related to seismicity, seismotectonics and seismic hazard assessment in Mexico.

Research Authors
Sawires, R., Santoyo, M.A., Peláez, J.A., and Corona-Fernández, R.D.
Research Department
Research Journal
Scientific Data
Research Member
Research Pages
241
Research Publisher
Nature Publishing Group
Research Rank
1
Research Vol
6
Research Website
https://www.nature.com/articles/s41597-019-0234-z
Research Year
2019

A state-of-the-art seismic source model for the United Arab Emirates

Research Abstract

NULL

Research Authors
Sawires, R., Peláez, J.A., AlHamaydeh, M., and Henares, J.
Research Department
Research Journal
Journal of Asian Earth Sciences
Research Member
Research Pages
104063
Research Publisher
NULL
Research Rank
1
Research Vol
186
Research Website
https://www.sciencedirect.com/science/article/abs/pii/S1367912019304158
Research Year
2019

Subsurface structural imaging of Ceboruco Volcano area, Nayarit, Mexico using high-resolution aeromagnetic data

Research Abstract

Ceboruco volcano is one of the largest volcanoes of the Trans-Mexican Volcanic Belt (TMVB), which extends along central Mexico. Among the western TMVB, Ceboruco Volcano comes in the second place after Colima Volcano in its activity. Also, it is considered as the only one that has historically-documented eruptions. Few geophysical studies have been published with the aim of studying the internal structure of the volcano. In the current work, and throughout the support of the CeMIEGeo-P24 geothermal exploration project, we aim to delineate the possible subsurface structural trends, to determine the approximate depth to the basement surface, and to provide an illustrative 3D model for its subsurface structure. To achieve such goals, a detailed analysis of the aeromagnetic data for the volcano area was performed. 2D interpretation was carried out for the aeromagnetic data. Edge detection filters, such as Tilt Derivative, and Analytic Signal, were used to map the contact/faults within the study area. In addition, 3D inversion was used to image the subsurface structure of the volcano. Aeromagnetic data was inverted using the GMSYS-3D inversion program by applying Parker algorithm. Four subsurface layers at depths of 250, 500, 750 and 1000 m were assumed during the inversion process. Results indicate that the limits “boundary” of the subsurface magma chamber of the volcano can be traced easily from the first subsurface layer. A secondary structure line appears towards the east from the volcano boundary and it can be observed from the inversion of the second and third layers. This indicates that both, the base of the volcano and the structure line, stem from the same source. Finally, they disappear in the inversion results for the last layer, which concludes that we reach the basement above which the volcano is formed. Combination of all obtained results with the geological information, helped to understand the main structure of the Ceboruco volcano.

Research Authors
Sawires, R. and Aboud, E.
Research Department
Research Journal
Journal of Volcanology and Geothermal Research
Research Member
Research Pages
162–176
Research Publisher
NULL
Research Rank
1
Research Vol
371
Research Website
https://www.sciencedirect.com/science/article/abs/pii/S0377027318303238
Research Year
2019
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