# Seismic and Geodetic Crustal Moment-Rates Comparison: New Insights on the Seismic Hazard of Egypt
## 6 Delimitation of Seismic Sources
### Seismic Sources along the Gulf of Aquba-Dead Sea Transform Fault System (EG-01 to EG-04)  
The Gulf of Aquba-Dead Sea Transform Fault (GoA-DST) can be divided into three main sectors [63] (see Figure 1b). The southern one (Jordan Rift) comprises the area from the junction of the Gulf of Aquba with the Red Sea and extends through the Dead Sea and the Jordan Valley (Figure 1b). It is characterized by the presence of N12\({}^{\circ}\) E to N20\({}^{\circ}\) E striking left-lateral strike-slip faults. The central sector (Lebanese Spplays) is running through Lebanon and southwest Syria (Figure 1b). It is characterized by about 200 km long NNE-SSW striking restraining bend [64]. Finally, the northern sector (El-Gharb Rift) of the GoA-DST is characterized by the occurrence of two N-S striking faults bounding the Ghab Valley and intersecting with both the East Anatolian Fault and the Cyprian Arc [42]. This intersection corresponds to the Hatay triple junction (Figure 1) between the Arabian, Nubian, and Anatolian plates [65]. The Gulf of Aquba (Figure 1) forms the southernmost segment of the GoA-DST. It has experienced the largest recorded instrumental earthquake in Egypt (the 22 November 1995, Mw 7.2, earthquake). It comprises three elongated _en-chelon_ basins transected by longitudinal faults [66]. Several tectonic basins were originated as a result of this en-echelon system, forming rhombic-shaped grabens (Figure 1b). These are the Tiran \"Dakar\" (from the south), Dakar, Aragonese, and Elat \"Aqaba\" (from the north) basins. The complex deformation pattern along the Gulf of Aquba is related to a left-lateral strike-slip motion  
Figure 5: Spatial distribution of lower hemisphere equal-area projection for the focal-mechanism solutions dataset (after [61]). Black lines refer to the faults defined by the EGSA [62]. Sizes and colors of the plotted focal mechanism are relative to their moment magnitudes and faulting types, respectively. NF: normal-faulting, NS: normal with a strike-slip component, SS: strike-slip faulting, TF: thrust faulting, TS: thrust with a strike-slip component, U: undefined. which dominates parallel to the main axis of the gulf, and a minor normal-slip component that dominates along the transverse faults [38; 67; 68; 69; 70]. In the current work, three main seismic sources (EG-01, EG-02, and EG-03; see Figures 3-5) were delimited along the GoA-DST, starting from the junction between the Gulf of Aqaba with the Red Sea (from the south) and reaching the northern latitude of 34\({}^{\circ}\) (from the north). The first defined seismic source is the EG-01 Tiran zone, which lies at the southern tip of the Gulf of Aqaba. No historical earthquakes are available for this source (Figure 3). The focal mechanism solutions inside this source is characterized by an average normal-faulting mechanism with a minor strike-slip component (Figure 5). The 3 August 1993 (Mw 6.1) earthquake represents the largest recorded magnitude (Figure 4) for the instrumental period within this source (Table 1). The second delimited seismic source (EG-02) covers the region extending from the Aragonese Basin passing through the Aqaba \"Elat\" Basin (along the Gulf of Aqaba) to the Arava Valley (to the north) (Figure 1b). The Gulf of Aqaba has been the focus of the largest recorded earthquake in Egypt, the 22 November 1995 (Mw 7.2) earthquake. In addition, paleoseismological investigations by [PERSON] and [PERSON] [71] deduced that border-faults of the Arava Valley could generate earthquakes bigger than Mw 6.0 for an average 1000-3000 years return period. Three historical earthquakes (Figure 3) have been reported in this source: the 18 March 1068 (felt intensity VIII, Mw 5.8), the 2 May 1212 (VII-IX, Mw 6.1), and the 4 January 1588 (VIII, Mw 5.8) earthquakes. The first one, in 1068, was reported in northern Hejaz, causing huge destruction along northwestern Saudi Arabia, and killing about 20,000 persons [59].