Complicated Lithospheric Structure Beneath the Contiguous US Revealed by Teleseismic S‐Reflections

Lithospheric discontinuities, including the lithosphere-asthenosphere boundary (LAB) and enigmatic mid-lithospheric discontinuities (MLDs), hold important clues about structure evolution of tectonic plates. However, P- S-receiver-function (PRF SRF) techniques, two traditional techniques to image Earth's deep have some shortcomings in imaging lithosphere discontinuities. Here, we propose a new method using reflections generated by teleseismic S waves (hereafter S-reflections) lithospheric which are less affected multiple phases than PRFs better depth resolution SRFs. We apply this data collected Transportable Array other regional seismic networks obtain high-resolution images below contiguous US. Beneath tectonically active Western US, observe negative polarity reflector (NPR) range 60–110 km, with greatly varying amplitude depth, correlates processes. interpret feature as LAB stable Central Eastern NPRs ranges 60–100 km 100–150 whose also vary significantly, appear correlate past these features MLDs Our results show reasonable agreement from PRFs, similar resolution, suggesting possibility joint inversion S-reflections constrain properties