Figure 1. The Gao and Shen 2014 shear wave velocity model of the upper mantle from full-wave ambient noise tomography reveals low-velocity anomalies (dark reds) along the Cascade back-arc. This horizontal slice was generated using the IRIS visualisation tool, for a depth of 94 km (Vs in km/s). The seismic velocity model is linked from the GeoPRISMS Data Portal and is tied to references.