Identifying Seismic Anisotropy Patterns in the Alps and Apennines with Splitting Intensity and Backazimuthal Dependencies

Abstract

<p>The current tectonics of the Alps and Apennines are driven and influenced by current and<br>past subduction systems. Computational advances over the years made it possible to<br>identify remnant and active slabs until great depths and large seismic deployments<br>revealed mostly clockwise rotation SKS splitting measurements. But the effects of layered<br>anisotropy and regional upper mantle flow through possible tears in the slabs remain<br>unknown. A comparison of several seismological methods can be a very efficient tool to<br>separate lithospheric and asthenospheric anisotropy. This study tries to understand if<br>anisotropy patterns change with depth in some regions (e.g., possible subslab mantle flow<br>in the Western Alps) and if tears can be identified with shear wave splitting measurements<br>(e.g., Central Apennines). Furthermore, splitting intensities will be analyzed for<br>backazimuthal dependencies and used to correct velocities in a full-waveform tomography.<br>By mapping and comparing existing and new anisotropy measurements (e.g., SKS, Pn<br>anisotropy, azimuthal anisotropy from surface waves tomography, and splitting intensities)<br>we intend to identify anisotropic depth dependencies.</p>