Determination of depth-dependent body wave attenuation beneath the Dead Sea Fault system

Abstract We derive a regional 1-D body-wave attenuation (Q⁻ 1 ) model for a segment of the Dead Sea Fault System using moderate earthquakes (3.0 ≤ M W ≤ 4.5). Q P and Q S are estimated through spectral modeling of stations within 350 km, with corner frequencies independently constrained using the empirical Green’s function method to reduce trade-offs between source and attenuation parameters. Path-averaged Q values increase approximately linearly with epicentral distance up to ~ 150 km for both P and S waves, followed by a gradual flattening toward an asymptotic regime. This transition is consistent with increasing mantle path contributions associated with the P g –P n and S g –S n phase crossover rather than an abrupt change in intrinsic attenuation properties. Inversion of the distance-dependent trends yields a layered 1-D Q(z) structure that reflects relatively low attenuation in the upper crust and higher effective Q at greater depths. Residual analysis indicates only modest lateral variability, suggesting that large-scale path effects dominate over local site controls within the resolution of this dataset. The resulting attenuation model provides physically consistent parameters for ground-motion simulations and offers a framework for future three-dimensional attenuation studies along the Dead Sea Fault System.