In the middle of the Mediterranean, the partly still active Apennines subduction system has been usually defined using tomographic images and available shear wave splitting measurements. In this paper we describe the new seismic anisotropy dataset for Central Italy, the region where the transition between Northern and Southern Apennines occurs. The new measurements show NW-SE fast polarisation directions beneath the belt, due to the retreat of the slab, NNE-SSW orientations from proper Adriatic mantle sources, and E-W directed anisotropy, attributed to mantle convection flow at the Thyrranian side. Additionally, the new data suggest the presence of a toroidal mantle flow through a tear in the Apenninic slab, from the Adria to the Tyrrhenian side. However, mantle circulation and flows, identified by the pattern of shear wave splitting results, seem different from what was proposed in previous geodynamic models. Indeed, our results support the presence of a vertical slab tear with limited dimension. In the geodynamic model we propose, the tear acts to accommodate a differential slab retreat. The slab partitioning results in a different pattern and strength of seismic anisotropy traced from the Central Apennines with respect to the adjacent Northern and Southern Apennines.

在地中海中部，部分仍然活跃的亚平宁俯冲系统通常使用断层扫描图像和可用的剪切波分裂测量来定义。在本文中，我们描述了意大利中部的新地震各向异性数据集，该地区发生了北部和南部亚平宁山脉之间的过渡。新的测量结果显示带下方的 NW-SE 快速极化方向，由于板片的后退，NN E- 来自适当亚得里亚海地幔源的 SSW 方向和 EW 定向各向异性，归因于 Thyrranian 一侧的地幔对流流动。此外，新数据表明，从亚德里亚到第勒尼安一侧的亚平宁板块撕裂处存在环形地幔流。然而，由剪切波分裂结果模式确定的地幔环流和流动似乎与以前的地球动力学模型中提出的不同。事实上，我们的结果支持存在尺寸有限的垂直板撕裂。在我们提出的地球动力学模型中，撕裂作用以适应不同的板后退。板块划分导致从中央亚平宁山脉与相邻的北亚平宁山脉和南亚平宁山脉追踪的不同模式和强度的地震各向异性。