The Calabrian Arc: three-dimensional modelling of the subduction interface.

ABSTRACT: The Calabrian Arc is a one-of-a-kind subduction zone, featuring one of the shortest slab segments (<150?km), one of the thickest accretionary wedges, and one of the oldest oceanic crust in the world. Despite a convergence rate of up to 5 mm/y and well-known intraslab seismicity below 40?km, its shallow interface shows little signs of seismic activity. Nonetheless, it has been attributed as generating historical large earthquakes and tsunamis. To gain insights into this subduction zone, we first made a geological reconstruction of the shallower slab interface (<20?km) and its overlying accretionary wedge by interpreting a grid of 54 seismic reflection lines (8,658?km) with 438 intersections within an area of 105?km2. Then, we constrained a deeper portion of the slab surface (40-350?km) using the seismicity distribution. Finally, we interpolated the two parts to obtain a seamless 3D surface highlighting geometric details of the subduction interface, its lateral terminations and down-dip curvature, and a slab tear at 70-100?km depth. Our 3D slab model of the Calabrian Arc will contribute to understanding of the geodynamics of a cornerstone in the Mediterranean tectonic puzzle and estimates of seismic and tsunami hazards in the region.

SUBMITTER: Maesano FE 

PROVIDER: S-EPMC5567100 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature