asem salama

Seismotectonic, paleotsunami deposits and tsunami scenarios are investigated along the north coast of Egypt in the framework of the tsunami ASTARTE European and the French-Egyptian IMHOTEP projects. The geology, geomorphology, seismicity, focal mechanisms, calculated stress inversion, and GPS data were used to identify the present day stress regime of the main active zones and the tsunamigenic zones. Trenches and cores were dug in Kefr Saber and EL Alamein sites. X-ray scanning, magnetic susceptibility, grain size analysis, sampling, macrofossil detections, XRD analysis, total organic and inorganic matter measurements and carbon dating are carried out to identify the paleotsunami signatures. The high-energy white sandy layer rich in reworked fossils at Kefr Saber are correlated with 21 July 365, while the four characteristic high-energy sedimentary layers at the El Alamein site are correlated with the historical tsunami events of 1600 BC, 21 July 365, 8 August 1303, and 24 June 1870.

We are grateful to the referee that helped us to clarify our text and figures and improve the presentation of our article. All comments, remarks and questions of each referee (and related annotations in manuscript) are addressed in our revised version (see underlined sections in article) and a detailed answer has been prepared in order to clarify the article (see attached sheets). RC1 (R. Paris) request mainly a rewrite and update

Sismotectonique, paleotsunami et le tsunami scenarios sont examines sur la cote du Nord de l'Egypte dans le cadre du tsunami europeen ASTARTE projet et le projet IMHOTEP francais-egyptiens. La geologie, la geomorphologie, seismicite, des mecanismes focaux, l'inversion de stress calculee et des donnees GPS utilisee pour identifier le regime de stress de jour present des zones actives et les zones de tsunamigene. Tranchees et carottes ont ete creusees a deux sites. Le balayage de radiographie, la sensibilite magnetique, l'analyse de taille de grain, l'echantillonnage, macrofossile detections, total des materiaux organiques et inorganiques et la datation au carbone est effectuee pour identifier les signatures tsunami. La couche sablonneuse blanche de haute energie riche en fossiles retravailles est correlee avec le 21 juillet 365 dans le Kefr Saber. Les quatre couches sedimentaires de haute energie a l'El Alamein sont correlees les tsunamis historiques de 1600 avant...

Major earthquakes display a significant tsunamigenic seismic activity (with Mw > 7) that may affect Africa continent. These events are from the far-field tectonics plates or even nearby tectonics boundaries. The main target of this study was to choose the most dangerous tsunamigenic zones according to the historical tsunami events and to update the tsunami hazard map of Africa published in UNISDR (2009). This was done by using nested bathymetry grids to reevaluate the maximum wave height using high-resolution (15 arcs per second) data near the African coastlines. Mirone version 2.10 software is used in these calculations. Four tsunamigenic zones sources affecting the African coastal zones have been tested at Andaman-Sumatra subduction zone, Makran trench zone, Western and Eastern Hellenic arcs. These tsunamigenic source zones were responsible for huge tsunamis generated from large historical earthquakes on 26 December 2004; 27 November 1945; 8 August 1303; and 21 July 365. Two to 4 m was the calculated maximum wave height resulted from the scenario 1 which arrived to the coasts of Tanzania, South Africa, and South Madagascar, while scenario 2 resulted in maximum wave height of 1–2 m toward the Somalian coast. The scenarios 3 and 4 were responsible for the maximum wave height of 2–4 m at the Egyptian and Libyan coasts. Preparing an early warning system will be required necessarily for the whole of Africa to overcome possible future high tsunami risk to the African coastal cities.

Geographic information system (GIS) and shallow seismic refraction tools are used in this study in order to detect some parts of this Pelusaic branch and delineate the groundwater aquifer. This Pelusaic branch was mentioned on ancient Egyptian monuments as ''The waters of the sun''. In this study, thirteen shallow seismic refraction profiles were measured near Tell Farma area. Using different analysis techniques and software for the data were analyzed and interpreted. Results interpreted of spot satellite image shows Pelusiac branch trace, and the subsiding of seismic surveys show clearly that parts of the Pelusaic paleoriver branch were found at depths ranged between 14 and 16 meter. Also, it is concluded that the Late Holocene -Early Pleistocene aquifer is the main aquifer in the study area.

Large earthquakes have affected Gulf of Aqaba with magnitudes ranging from 6 to 7.3 as examples in years 1068, 1212, 1588 AD during historical records. In recent seismicity, a large earthquake occurred on 22 November 1995, of Mw 7.3 that triggered a small tsunami that affected the port of Nuweiba in Egypt, Eilat and Aqaba beaches. The epicenter of this earthquake has been occurred between the Aragonese and Eilat basin at the central part of the Gulf of Aqaba. The long low seismicity, especially for significant events at the southern Arnona fault, manifested its act as possible seismic gap with an expected a future rupture of Mw 7.2 earthquake. This event will affect the three countries Egypt, Saudi Arabia, Jordon Israel coastal cities using two scenarios. We used Mirone version 3.10 software to calculate the maximum wave height at the Gulf of Aqaba cities. The main two tested scenarios depend on the 22 November 1995 which was earthquake located at the Aragonese fault and the 1068 or 1839 AD earthquake with epicenters at Arnona fault at Aqaba basins. The Nov.,1995 scenario will produce a maximum wave height of 2.10 meters in the Nuweiba and 0.5 meters at Dahab coastal cities and 0.7 meters at Eilat city. The Arnona fault second scenario will produced a maximum wave height of 1.2 m Dahab, 1.8 m Nuweiba coastal cites at Egypt and 2.10 meters at Magna Saudi Arabia with less wave height to 1.2 m at Eilat city and Aqaba at Israel and Jordon respectively.