Structure and Seismicity of the Dead Sea Fault and the Galilee Revealed by 3D Earthquake Tomography

Strike-slip fault systems near regions of oblique tectonic convergence/divergence commonly develop bends, stepovers, and other complexities that control crustal deformation, stress localization, and associated geophysical processes. Here, we investigate the complex crustal structure of the strike-slip Dead Sea Fault (DSF) system and the Galilee, in an area bounded by the Lebanese Restraining Bend in the north and by the intraplate Carmel-Gilboa-Faria Fault (CGFF) system in the south. Using traveltime data from ∼1,500 local earthquakes (1.5 < M_W), we present 3D velocity models for P-waves (Vp), S-waves (Vs), their ratio (Vp/Vs), and a catalog of relocated seismicity for this complex tectonic region. Along the DSF, shallow differences between a high-velocity western side and a low-velocity eastern side form a bimaterial fault interface. Within the CGFF system, major sedimentary basins exhibit lower velocities than the surrounding crust. In the northern Kinneret basin (the Sea of Galilee), elevated Vp/Vs values suggest significant rock damage, possibly due to intense seismic activity. Increased mean Vp/Vs values and seismic activity below 15 km depth indicate a transition zone, perhaps related to changes in crustal mechanical properties. Relocated seismicity is generally confined to vertical fault segments along the DSF, with activity alternating between the border faults of the system. Beneath the Kinneret basin, shallow seismicity delineates a high-angle, eastward-dipping fault surface on the western side, possibly forming part of a negative flower structure beneath the basin. These observations provide new insights into the crustal structure of this region, revealing key features related to the DSF and CGFF systems.