Identification of the dynamic subsurface structures and their seismic implications based on geophysical methods at the southern part of Cairo area, Egypt

Abstract

The main purpose of paper is to detect the active subsurface structures and their seismic implications located at the southern part of Cairo area. To achieve this target, the reduction-to-the-pole (RTP) aeromagnetic, ground magnetic, magnetotelluric, and seismological data were used. The RTP aeromagnetic data was used to delineate the regional extensions of the subsurface structures along a wide area. The activities of the detected structures were confirmed from the distributions of the earthquake epicenters along the investigated area. The type of the fault structures was identified using the focal mechanism analyses for the seismological data. Moreover, the active subsurface structures have been traced using a detailed ground magnetic survey for the study area. In addition, the magnetotelluric survey was carried out crossing the fault structures which detected previously from aeromagnetic. The results show that the selected area is identified as active zone for earthquakes. This zone extends from Gulf of Suez at the east crossing Wadi Araba and Nile River to south Giza and Cairo cities where the 12th October 1992 earthquake’s epicenter exists. Finally, the Curie magnetic depth investigation indicates the activities of these structures where the curie magnetic depths reach less than 8 km.