Shallow fault systems of thrust anticlines responding to changes in accretionary prism lithology (Nankai, SE Japan)

Three-dimensional (3D) pre-stack depth migrated seismic data are used to analyse the geometry and growth of shallow faults associated with tectonic shortening in four (4) prominent thrust anticlines off Nankai, SE Japan. The show a trenchward increase horizontal deform seafloor at present. They shortened overburden strata by 7143 m Late Quaternary, reflecting 32.9% response plate subduction. A significant number closely spaced segmented fault arrays is observed their hinge regions. Vertically local throw maxima between 5 14 relate existence more competent (strong) intervals, or layers. Incompetent (weak) intervals record relatively small values 2 m. We that presence spaced, stratigraphic levels can have impact on stress distribution, controlling near-seafloor strain accretionary prisms as Nankai's. mechanical layering likely continue control accumulation posed reactivate during events.