SEISMIC HAZARD STUDY FOR THE NORTH WESTERN PART OF EGYPT

Abstract

Natural, physical and environmental processes that occur near or at the surface of the earth can produce unexpected events of unusual magnitude or severity. Such occurrences are generally regarded as natural hazards. The outcome can be catastrophic, frequently resulting in damage to property, injury to humans and other organisms, and tragically even loss of life. In these cases, natural hazards are considered natural disasters. The community of scientific research plays an important role in the mitigation of such disasters by the precise assessment and determinations of their sources. Seismic hazard represents the main natural hazard. Proceeding from this, the current thesis is preformed for scientific analysis and practical assessment of seismic hazard in the North western part of Egypt as step towards the seismic risk mitigation in the north western part of Egypt. For this purpose, the current thesis is organized in five main chapters as follows: Chapter One: It gives a brief account on geological setting, structure and tectonic elements of Egypt and a description of geological characteristics of the study area. The study area is covered with a thick sequence of relatively undisturbed sedimentary strata of Paleozoic, Mesozoic and Cenozoic age. Also, there are few lines of major faults and the few folds noted are minor rolls with gentle dips and large amplitude. Several tectonic events affected the north Western Desert. The most important tectonic event occurred during the late Cretaceous and early Tertiary and was probably related to the movement of the North African plate towards Europe. It resulted in Chapter 6 Summary and conclusions 136 the elevation and folding of major portions of the north Western Desert along an ENE-WSW trend (Syrian Arc system) and the development of faults of considerable displacements (Said, 1990) Chapter Two: The seismicity of the study area is presented through the compilation of the required earthquake catalogue for assessment the seismic hazard in the area of interest. The earthquake catalogue is compiled from all available resources taking into account the paleo-seismological studies and the historical earthquakes. The catalogue covers a spatial region spanning 19o to 37o E and 25o to 37o N. all events having an assigned magnitude of 3.0 and above on any magnitude scale are included. An extensive effort has been put to remove the duplicate events by both automated