Uppermost mantle P-wave seismic velocity structure of the Juan de Fuca and Gorda plates (VanderBeek and Toomey, 2019)

This data set is a tomographic model of mantle P-wave speeds beneath the Juan de Fuca and Gorda plates offshore of the Pacific northwest. The model conforms to a surface located 1 km beneath the oceanic Moho. Due to the nature of the seismic data used to construct this tomographic image (primarily Pn head waves), P-wave speeds reflect an average over the uppermost ~7 km of the oceanic mantle. The model and results are described in VanderBeek and Toomey (2019). In summary, the model was constructed by inverting 3363 travel-times from 162 local earthquakes recorded by Cascadia Initiative ocean bottom seismometers. Travel-times were inverted using an iterative anisotropic tomography algorithm. The isotropic and anisotropic component of the model is provided as an ASCII file (see header comments in file for file structure). The isotropic component of the model (the P-wave speed) is also provided as a data layer in GeoMapApp. The data set was generated as part of the projects called "Structure and Dynamics of the Lithosphere-Asthenosphere System Beneath the Juan de Fuca Plate" and "Understanding Subduction Systems by Linking Anisotropic Seismic Imaging and Geodynamic Modeling". This work was supported by the National Science Foundation under grants OCE‐1139701, OCE‐1333196, and EAR‐1520694 to the University of Oregon.