Seismic Event Coda‐Correlation: Toward Global Coda‐Correlation Tomography

Dynamic ray tracing and traveltime corrections for global seismic tomography

We present a dynamic ray tracing program for a spherically symmetric Earth that may be used to compute Fréchet kernels for traveltime and amplitude anomalies at finite frequency. The program works for arbitrarily defined phases and background models. The numerical precisions of kinematic and dynamic ray tracing are optimized to produce traveltime errors under 0.1 s, which is well below the data...

On the relevance of Born theory in global seismic tomography

[1] Does the application of seismic Born theory, as opposed to simpler ray theory, lead to an improvement in tomographic images of the Earth? In recent publications, Montelli et al. (2004a, 2004b) and van der Hilst and de Hoop (2005) among others have expressed opposite opinions. We propose a quantitative approach to the comparison of tomographic images, which we apply to the case of surface-wa...

Seismic Tomography

The inversion of seismic travel-time data for radially varying media was initially investigated by Herglotz, Wiechert, and Bateman (the HWB method) in the early part of the 20th century [1]. Tomographic inversions for laterally varying media began in seismology starting in the 1970's. This included early work by Aki, Christoffersson, and Husebye who developed an inversion technique for estimati...

Diffraction and seismic tomography

Diffraction tomography is formulated in such a way that the data ( t ravel t ime4r waveform perturbations) are related to the medium perturbations through the sum of two terms. The first term is the ray integral of ordinary tomography and involves only phase perturbations. The additional diffraction term involves both phase and amplitude perturbations. The diffraction term is linear in the grad...

Seismic Traveltime Tomography 1