New geodetic constraints on the role of faults and blocks versus distributed strain in the Nubia-Arabia-Eurasia zone of active plate interactions

Abstract

We present a broad view of present-day motions and deformations derived from uniform processing of GNSS observations within the Nubia-Arabia-Eurasia zone of plate interaction. The new observations we present provide a similar to 29% increase in the number of velocity determinations, a reduction in average station spacing from similar to 76 km to similar to 39 km, and an improvement in velocity uncertainties (for similar to 126,000 km(2), bounded by the North and East Anatolian Faults exhibits internal velocity differences of <0.5 mm/year, indicating strain rates of < similar to 1.5 nanostrain/year. Geodetically constrained fault slip rates obtained from this simplified approach are comparable to geologic rates, indicating that major faults have controlled the recent geologic evolution of the region (i.e. 5-10 Myr). The pattern of present-day deformation, including increasingly fast motions towards the Hellenic trench, and the roughly simultaneous opening of all the major Mediterranean basins in the early Miocene with the slowing of the Nubia-Eurasia convergence, support conceptual models that foundering and rollback of the subducted Nubian slab beneath the Aegean is the primary mechanism responsible for present-day motion and internal deformation of the Anatolian-Aegean region.