Three-dimensional S-velocity structure of the mantle along the Tethyan margin

Various three-dimensional mantle models exist for parts of the mantle along the Tethyan margin. For purposes of studying the lateral and vertical continuity and edges of structural features, as well as for ultimately predicting seismograms for this region we venture to unify these models into a single 3-D model by jointly inverting a variety of different seismic data. Our study of the Tethyan margin extends from the western Mediterranean region to the Hindu Kush and encompasses northeastern Africa, the Arabian peninsula, the Middle East, and part of the Atlantic Ocean for reference. We jointly invert regional waveforms, surface wave group velocity measurements, teleseismic S arrival times, and crustal thickness estimates from receiver functions and refraction lines. These measurements are made from a combination of MIDSEA, PASSCAL, GeoScope, Geofon, GSN, IDA, MedNet, national networks, and local deployments throughout the region. These data types have complementary resolving power for crust and mantle structures, vertical and lateral variations, shallow and deep mantle features, local and global structure, and are jointly inverted to image the complexity of this tectonically diverse area. We have fitted the waveforms of regional S and Rayleigh waves from over 3800 seismograms using Partitioned Waveform Inversion. We have accumulated over 300 crustal thicknesses from receiver functions, gravity measurements, and refraction profiles. We have measured Love and Rayleigh wave group velocities for hundreds of new paths recorded at the MIDSEA stations and combined them with thousands of existing paths transecting the region. We have over 3000 teleseismic S arrival times measured through cross correlation and 30000 more from picks originally reported to the ISC. We demonstrate our inversion methodology and discuss results from combining these new measurements in a preliminary joint inversion for S velocity structure. We discuss features of our new model, which includes oceanic structure, cratons, subducting slabs that penetrate into the lower mantle and others that do not, low- velocity mantle plumes, rifts, plateaus, and basins.