Evolution in seismic monitoring system and updating seismic zones of Egypt

Abstract

ABSTRACT On 3 September 2015, an unexpected earthquake with magnitude MB = 4.5 occurred in a completely silent area, located at 40 km south El Alamein city north western desert, where there are ~ 20 million pieces of unexploded ordnance. This study aims to: i) review and interpret the widespread seismic activity in Egypt during the last three decades, and ii) delineate the active seismic source zones map of Egypt based on realistic assumptions. These assumptions include only the real and accurate seismic events from the whole earthquake catalogue of Egypt. The idea based on the accuracy of the monitoring system, magnitude size of earthquakes, and detailed structure elements map of Egypt. The seismic catalogue of Egypt was updating to the end of 2019 including the historical and instrumental earthquakes since −2200 BC. The seismicity map of Egypt was outlined along five interval periods based on the significant evolution in the seismic monitoring system. The advanced monitoring period in the detection and location of seismic events in entire Egypt was supposed to begin in 2003 where the ENSN almost accomplished. Seismicity of advanced monitoring period 2003–2019 can be used as a tracer of real seismicity boundaries entire Egypt. Active seismic source zones map was delineated based on the advanced monitoring period and the unified Mw ≥ 4.5 instrumental catalogue from 1900 to 2019. To validate the seismic zones model, it compared with the structural elements map and given a rational matching. The new local seismic spots entire Egypt was discussed because of the invention in the seismic monitoring system entire Egypt and attributed to the misdetection and/or dislocation events due to the lack of monitoring system before the accomplished of ENSN. In conclusion, a validated active seismic zones map of Egypt was delineated using real and accurate seismic and geologic data based on powerful assumptions.