Supplementary information for Structure of the European Upper Mantle revealed by adjoint tomography

The main tectonic features in our study region are indicated in Fig. S1. We use 190 earthquakes for the iterative structure inversion (Fig. S2a). Most of the earthquakes are shallow (< 30 km), occurred from 1996 to 2011 (Fig. S3), and are evenly distributed along the North Atlantic Ridge and the Mediterranean-Himalayan belt. Initial source parameters (e.g., centroid time, location, etc.) are collected from the Global Centroid-Moment-Tensor (CMT) website (www.globalcmt.org). All source parameters are reinverted in the 3D global starting model using 3D Green’s functions calculated based on a spectral-element method (SEM) [1, 2, 3, 4]. To obtain good azimuthal coverage, seismic waveforms recorded by