Collaborative Research: Space-Based Measurements of Crustal Deformation along the Entire Dead Sea Fault System (Eastern Mediterranean)

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This study assembles the first, comprehensive view of near-field strain along the entire Dead Sea fault system using Global Positioning System (GPS) measurements. The fault system, a prominent element of the eastern Mediterranean geodynamic framework, bounds the Arabian and Sinai plates and links proto-oceanic spreading in the Red Sea (Gulf of Aqaba) with the Arabian-Eurasian collision (southern Turkey). Spanning more than 800 km, the left-lateral Dead Sea fault system ranks among the large continental transform systems of the world. With mean recurrence intervals between 500 to 1,100 years for large earthquakes on different sections and a paucity of large (magnitude greater than 7) earthquakes during the past two centuries, the fault system is an excellent locale to understand the relationship between earthquake recurrence and crustal deformation along a slow moving (less than 10 mm/yr) transform fault. By the fourth year of this project, most GPS sites (survey and new continuous) will have 1-sigma uncertainties less than 0.5 mm/yr. The resulting GPS velocity field will provide a basis for kinematic and geodynamic modeling of the Dead Sea fault system that will elucidate fundamental aspects of transform tectonics, as well as broader issues pertaining to eastern Mediterranean tectonics (e.g., internal deformation of the Sinai and Arabian plates, nature of the Dead Sea fault-East Anatolian Fault-Cyprus arc triple junction, age and geological evolution of the Dead Sea fault). Key issues addressed by the research include: 1) variation of slip rates along the transform and the implications about existing plate tectonic models for the region; 2) comparison between present-day slip rates with geological estimates with implications for the timing of initiation of the main parts of the Dead Sea fault system and its relationship to the Arabia-Eurasia collision and Red Sea rifting; 3) slip transfer and strain partitioning at fault bends and step-overs (e.g., the Lebanese restraining bend and the Dead Sea Basin); 4) the influence of lithospheric rheology on strain partitioning along a transform.The Dead Sea fault system ranks among the major continental transform fault systems in the world. In addition to elucidating geodynamic aspects of the eastern Mediterranean region, focused studies on the fault system can yield insight into tectonic and geodynamic processes operating along continental transforms, in general. From a structural perspective, the Dead Sea fault system is relatively simple when compared with other transform fault systems. The structural simplicity permits relatively straightforward modeling of the earthquake cycle and crustal deformation processes, which can yield fundamental insight pertinent to more complicated fault systems, such as the San Andreas fault system. To this end, sufficient historical and palaeoseismic records of large earthquakes exist to facilitate such studies along most of the Dead Sea fault system. This study provides the critical constraints on present-day crustal deformation using high-precision GPS measurements. Additionally, results from this project will be directly applicable for an urgently needed improvement in the understanding of the earthquake hazard in a region that is potentially overdue for a large earthquake. Regional earthquake hazard is a concern for nearby megacities including Damascus, Beirut, Amman, Aleppo, and Jerusalem.