Subduction rollback, slab breakoff, and induced strain in the uppermost mantle beneath Italy

Abstract

Differences in seismic anisotropy revealed by split SKS waves that traverse the upper mantle beneath the Italian region reveal four areas of internally coherent anisotropic strength, providing evidence for mantle strain partitioning. When compared to uppermost mantle structure imaged by tomography, the sequence of these areas displays a straightforward parallelism. Under proper assumptions, the correspondence between areas of coherent splitting degree and areas of coherent velocity perturbations offers new insights into the late evolution of subduction in Italy and their effect on mantle strain.