Continental dynamics of the North American plate

We study the continental dynamics of the contiguous U.S. using global mantle flow models. Our study focuses on three aspects: upper mantle horizontal shear and how it forms seismic anisotropy, basal tractions from the sublithospheric mantle, and how they contribute to forming the present day surface topography, and the flow induced surface deformation. We study the significance of multi-layer seismic anisotropy in the eastern U.S., and the role of small scale flow related shear that affects the anisotropy alignment in the western U.S. Our study proposes the importance of understanding the complexity of sublithospheric mantle flow in the western U.S. With predictions of dynamic topography, we present the effect of plate boundary dynamics on the western U.S. flow, and the various levels of support from mantle flow to the western Cordillera and Intermountain Region. We further constrain the lithosphere-sublithosphere interactions with vertical crustal motions. We observe mantle flow contributions to the subduction zone related deformation with along strike variations, reduced mantle flow support at the center of Great Basin, and the uplift at the Sierra Nevada. We propose the next step of research towards a comprehensive analysis using flow predicted deformation and lithospheric heterogeneity