Near surface assessment of New capital city using geophysical techniques

Abstract

ABSTRACT The Egyptian government announced the creation of a brand new capital city to address Cairo’s rapid population expansion and improve the quality of life for citizens, which is thought to have a strong demand for housing. In this study, we focused on the application of geophysical techniques, specifically Electrical Resistivity Tomography (ERT) and Very Low Frequency Electromagnetic Method (VLF-EM), to investigate the shallow subsurface in the New Capital city in Egypt. The study area is located in the eastern part of Cairo and is characterised by Oligocene and Miocene rocks. The ERT profiles reveal four geoelectrical layers based on resistivity values, with the first layer (Resistivity >300 Ω.m) interpreted as sand and conglomerate on the surface or basalt below. The second layer (100–300 Ω.m) is identified as sandstone, while the third layer (15–100 Ω.m) is interpreted as humid sandstone. The fourth layer (1–15 Ω.m) is characterised as shale. The abrupt changes in resistivity values horizontally indicate the probability of subsurface structures, including faults. The VLF-EM method is used to identify faults and cracks in the earth’s crust. The results provide information on the size, shape, and depth of both shallow and deep subterranean conductors. Anomalies of high conductivity suggest fault or fracture zones influencing underlying strata.