Simulation of strong ground motion parameters of the 1 June 2013 Gulf of Suez earthquake, Egypt

Abstract

This article aims to simulate the ground motion parameters of the moderate magnitude (ML 5.1) June 1, 2013 Gulf of Suez earthquake, which represents the largest instrumental earthquake to be recorded in the middle part of the Gulf of Suez up to now. This event was felt in all cities located on both sides of the Gulf of Suez, with minor damage to property near the epicenter; however, no casualties were observed. The stochastic technique with the site-dependent spectral model is used to simulate the strong ground motion parameters of this earthquake in the cities located at the western side of the Gulf of Suez and north Red Sea namely: Suez, Ain Sokhna, Zafarana, Ras Gharib, and Hurghada. The presence of many tourist resorts and the increase in land use planning in the considered cities represent the motivation of the current study. The simulated parameters comprise the Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), and Peak Ground Displacement (PGD), in addition to Pseudo Spectral Acceleration (PSA). The model developed for ground motion simulation is validated by using the recordings of three accelerographs installed around the epicenter of the investigated earthquake. Depending on the site effect that has been determined in the investigated areas by using geotechnical data (e.g., shear wave ​velocities and microtremor recordings), the investigated areas are classified into two zones (A and B). Zone A is characterized by higher site amplification than Zone B. The ground motion parameters are simulated at each zone in the considered areas.The results reveal that the highest values of PGA, PGV, and PGD are observed at Ras Gharib city (epicentral distance∼11km) as 67cm/s2, 2.53cm/s, and 0.45cm respectively for Zone A, and as 26.5cm/s2, 1.0cm/s, and 0.2cm respectively for Zone B, while the lowest values of PGA, PGV, and PGD are observed at Suez city (epicentral distance∼190km) as 3.0cm/s2, 0.2cm/s, and 0.05cm/s respectively for Zone A, and as 1.3cm/s2, 0.1cm/s, and 0.024cm respectively for Zone B. Also the highest PSA values are observed in Ras Gharib city as 200cm/s2 and 78cm/s2 for Zone A and Zone B respectively, while the lowest PSA values are observed in Suez city as 7cm/s2 and 3cm/s2 for Zone A and Zone B respectively. These results show a good agreement with the earthquake magnitude, epicentral distances, and site characterizations as well.