On the relationships between slab dip, back‐arc stress, upper plate absolute motion, and crustal nature in subduction zones

摘要: [1] Statistical analysis of modern oceanic subduction zone parameters, such as the age a downgoing plate or absolute motions, is performed in order to investigate which parameter controls dip slab and, conversely, what influence geometry on upper behavior. For that purpose, parameters have been determined from global databases along 159 transects all zones are not perturbed by nearby collision ridge/plateau/seamount subduction. On basis tomographic images, slabs penetrate through, lie on, 670 km discontinuity also identified. The results statistical follows: (1) Back-arc stress correlates with dip, i.e., back-arc spreading observed for deep dips (deeper than 125 km) larger 50°, whereas shortening occurs only less 30°. (2) Slab motion overriding plate. correlation even better when lies more penetrates discontinuity. (3) Slabs steeply, about 20° average, beneath plates continental ones. (4) steeply average 10° near edges. (5) does correlate magnitude pull, subducting lithosphere at trench, thermal regime lithosphere, convergence rate, polarity (east versus west). present study provides evidence plays an important role well strain. Retreating often ones and thus may partially explain steeper plates. One can infer low compression advancing plates, steep associated extension retreating Excess weight old counterbalanced other forces, probably asthenospheric origin, lateral mantle flow edges anchor determine dip.