EAGER: Vectorial Anisotropic Body and Surface Wave Tomography Using USArray Data

University Of Florida, Gainesville FL

Investigators

Abstract

Robust modeling of both strength and orientation of anisotropic structure is a tantalizing tool for constraining the dynamic processes in the lithospheric and sub-lithospheric mantle beneath North America, directly meeting the Earthscope goals of understanding the active deformation of North America and tying it to deep Earth structure and dynamics. The long term goal of this research is to develop more detailed regional and global models of seismic anisotropy that can both illuminate the dynamic processes of the upper mantle, as well as allowing for direct comparison with geodynamically predicted models. The objective of this EAGER application, which is the next step towards this long-term goal, is to develop a new approach to image dynamic processes in the lithospheric and sub-lithospheric mantle beneath North America with a novel technique combining both body wave and surface wave observables that allows for finite-frequency vectorial tomography. The international collaboration proposed here is uniquely suited to bring these approaches the PI and the research group of S´ebastien Chevrot have been working on together and take advantage of the incredible dataset offered by the USArray transportable array to move towards obtaining an unprecedented model of anisotropic structure beneath North America. The project will develop these models by pursuing the following specific aims. 1) Perform synthetic testing of joint inversions using this new approach. The inversions will allow us to gain unprecedented information about both strength and orientation of anisotropy. 2) Assemble and process USArray shear splitting and surface wave data and merge and improve existing software between the two research groups. Dense data coverage of both splitting intensity and multi-taper fundamental mode phase delay will be possible, and since both approaches have been developed from a consistent elastic parameterization, merging the software and performing joint inversions of the data shows great potential for greatly improving the capabilities of anisotropic modeling.