Continental Lithospheric Deformation Along a Major Strike-Slip Fault Zone: The Central North Anatolian Fault Zone, Turkey

University Of Arizona, Tucson AZ

Investigators

Abstract

Continental Lithospheric Deformation Along a Major Strike-slip Fault: The Central North Anatolian Fault Zone The 1500 km long North Anatolian Fault Zone (NAFZ) is one of the world's largest active continental strike-slip faults and forms the northern margin of the Anatolian block or plate. All indications are that the NAFZ is a newly coalescing continental transform plate boundary. This gives us an opportunity to study a snapshot of lithospheric deformation in its evolution into a plate boundary at the surface and at depth. Despite much geological work at the surface, the deep structure of the NAFZ is relatively unknown. We propose to study the central portion of the NAFZ using data from a 2-year, 40 station portable broadband seismic deployment to address the following questions: (1) Is the NAFZ a lithospheric-scale transform fault and if so, how does the lithosphere respond to the deformation? Is the NAFZ a thin vertical fault at depth or a broad zone of deformation? Are the crust and upper mantle deformation coupled or decoupled? (2) How does the deeper asthenospheric flow signature relate to the crustal velocity field (as defined by GPS studies) and westward tectonic escape model for the Anatolian plate? (3) Does the spatial distribution and composition of magmatism along the fault zone in the last 10 Ma relate to the deep structure of the fault? (4) How do the fault segments, rupture segments and major splays interact along strike and at depth? What is the depth of the seismogenic zone, and how does it relate to the segmentation defined by the major earthquakes this century? We will use seismic tomography (teleseismic, regional and local), receiver function analysis, modeling of regional waveforms, surface wave dispersion, crust and mantle anisotropy measurements, gravity modeling, and seismicity studies to address these questions.