Path-averaged delay times for seismic tomography

Abstract

SUMMARY The delay times reported for 427 17 476 mantle and core phases in the ISC-EHB Bulletins for the years 1964–2018 are averaged into 120 41 671 summary rays. For each summary ray, I estimate the standard variance of the mean delay and an upper bound for use in tomographic inversion. The trade-off between model norm and the fit to mantle P-wave data shows that the regularized tomographic problem for these data is well posed, with data adequately fit between their error bounds.