Stress field and tectonic regime of the Eastern Mediterranean from inversion of earthquake focal mechanisms

• Published in: Journal of Asian earth sciences Vol. 262; p. 106005
• Main Author: Ali, Sherif M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2024
• Subjects: Eastern Mediterranean; Focal Mechanisms; Slip Tendency; Stress Tensor; Tectonic Regime; Win-Tensor; Win-Tensor; Slip Tendency; Eastern Mediterranean; Focal Mechanisms; Stress Tensor; TectonicRegime
• ISSN: 1367-9120; 1878-5786
• DOI: 10.1016/j.jseaes.2023.106005

•The stress field in the Eastern Mediterranean region is complex and exhibits multiple stress regimes.•Analysis of 1258 earthquake focal mechanism solutions was used to estimate the orientations of the regional principal stress axes.•The predominant tectonic regimes in the Eastern Mediterranean have been estimated.•The study area was divided into zones based on structural and deformation patterns.•The stress field and slip tendency in each zone has been determined. The formal stress inversions of 1258 earthquake focal mechanism solutions reveal the presence of six distinct stress regimes. However, the predominant tectonic regimes comprise normal faulting (39%), strike-slip faulting (29%), thrust faulting (25%), and unspecified oblique faulting (7%). The division of the study area into zones based on structural and deformation patterns has provided valuable insights into the variations in the stress field and tectonic processes within this seismically active region. For each designated zone, reduced stress tensors were derived using the improved right dihedron method and the rotation optimization technique implemented by the Win-Tensor software. The stress field derived from the entire dataset is characterized by R′ = 1.0 and an NW-SE SHmax orientation, strongly influenced by the tectonic stress regime of the Hellenic Arc. In specific regions such as CYS, CEM, and WEM, the prevailing tectonic regimes is characterized by a predominant compressive setting with a stress index (R' = 2.0 to 2.5). This pattern aligns with neotectonic deformation associated with the subduction of the African Plate beneath the Eurasian Plate. The EMZ Zone exhibits a strike-slip tectonic regime with an R' of 1.50, primarily influenced by the Dead Sea Transform Fault. This fault accommodates differential motion between the African and Arabian plates in the NNE direction, resulting in left-lateral strike-slip motion along the plate boundary. The mean slip tendency values, varying between 0.62 and 0.66, suggests that the faults in the study area are appropriately oriented for slip or shear displacement, indicating an elevated probability of reactivation.