الفهرس 
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Abstract
Blasting explosions in Egypt occur in quarry and mining areas for cement and gold production. Sometimes, both earthquakes and quarry explosions occur together in complicated tectonic zones. The Egyptian earthquake catalogue is generally contaminated by these industrial explosions. Therefore, the discrimination of these events is essential to identify real seismicity, nature of tectonic faults and for seismic hazard assessment in Egypt. Quarry and mining events for the period 1997-2015 are analyzed to find their locations and to identify areas of contamination with micro earthquakes. During this period, the catalogue includes 15769 artificial events recorded by the Egyptian National Seismological Network stations with ML ≤ 3.5. According to their distributions, Egypt is divided in to five zones, where Northern Egypt zone is the highest among them. In this study, many steps are implemented for discrimination purpose. The first step is to map the artificial sources after identifying them based on source location, time, magnitude and depth, where statistical analysis is applied on the quarry blasts catalogue in the second step. In the third step, spectral analyses are used to compare the P- and S-waves displacement amplitude spectra for both earthquakes and quarry blasts focusing on the ranges of corner frequencies and source spectral shapes. In addition, the amplitude velocity spectra at the same stations are analyzed to study spectral properties and frequency content of both events. Finally, from corrected spectra, the average source parameters are computed for each event to construct and develop some quantitative criteria and scaling relations for the discrimination purpose. The comparison between the ratio fc(P)/fc(S) versus Mw for both earthquakes and quarry blasts events is also constructed. This relation shows that, the shift fc(P) relative to fc(S) is larger for explosions (1.52-2.84) than for earthquakes (1.04-1.51). This parameter is independent on the moment magnitude Mw. Thus, its discrimination threshold value to separate quarry explosions from earthquakes in Egypt is estimated as " ~ " 1.51-1.52. A relation between fc(P), fc(S) and Md is constructed for both earthquakes and explosions, separately to check the dependency of corner frequency on duration magnitude. It is found that the displacement corner frequency of explosions is independent on the duration magnitude; on contrary to earthquakes. In addition, frequency content analysis of velocity spectra is also done. It shows that, earthquakes have a wide range of frequency content (2 - 20 Hz) with a slow decay of signals energy. On contrast, explosions have a limited range of frequency (2 - 8 Hz) and the energy of signals decay rapidly. The last step in this work is based on the time-frequency analyses with applying a liner (LDF) and quadratic (QDF) algorithms for events classification. Many tools are used; S/P amplitude ratio (AS/AP – log AS), source complexity and spectral ratio (C-Sr), power of event and complexity (Pe-C), and power of event and spectral ratio (Pe-Sr) in the discrimination process. The Pe-Sr discrimination technique has the highest success rate for most stations. The results are taken in consideration when at least three of these four methods yield the same event type, this will be the best result. Moreover, the use of the linear and quadratic algorithms provides significant results with high discrimination performance. Applying these methods, the final discrimination results of the total 639 events in Northern and Central Egypt are; 289 events as earthquakes (EQ) and 346 as quarry blasts (QB), while 4 events still misclassified.