Rift-related active fault-system and a direction of maximum horizontal stress in the Cairo-Suez district, northeastern Egypt: A new approach from EMR-Technique and Cerescope data

• The EMR-Technique using Cerescope is applied here for the first time to the study area.
• An active fault system was detected following the old rift-related trends indicating an ongoing activity.
• The detected active faults and the direction of maximum horizontal stress are corresponding with the active trends estimated in many seismic studies on northern Egypt.
• The maximum horizontal stress directions were used for a new stress map for the study area.
• This study will add new data to the WSM (World Stress Map) of Heidbach et al. (2008).

An active fault system has been detected along the Cairo-Suez district in northeastern Egypt, applying the EMR-Technique using Cerescope. The E-W (old Mediterranean) and NW-SE (Red Sea-Gulf of Suez) fault-trends are estimated to have ongoing activity. Horizontal EMR-measurements indicate a NW to NNW orientation as a maximum horizontal stress direction (σ1), whereas an E-W orientation to has a secondary tendency. A simplified stress map for the Cairo-Suez district is constructed from the horizontal stress data measured at about 20 locations within the district. The mapped stresses will contribute to the stress data of the Cairo-Suez region on the world stress map (WSM). The present study results indicate rejuvenation of the inherited Mesozoic E-W oriented and Oligocene-Miocene rift-related NW-SE oriented faults. The transfer of rift-related deformation from Red Sea-Gulf of Suez region, which is currently undergoing an extensional stress regime in NE to NNE direction, would explain a seismotectonic activity of the Cairo-Suez district. These results are consistent with a present day NNW oriented compressional stresses attributed to a convergence between the African and Eurasian plates.