Probabilistic inversion of circular phase spectra: Application to two-station phase-velocity dispersion estimation in western Canada

Author(s)
Jeremy M. Gosselin, Pascal Audet, Clement Esteve, Andrew J. Schaeffer
Abstract

Periodic directional and temporal measurements are common in seismology, and necessitate specific statistical analyses that are appropriate for circular quantities. In this work, we explore the use of a von Mises distribution as a representation of errors on circular seismological observations. Specifically, we automate the estimation of surface-wave phase-velocity dispersion for the teleseismic two-station method, which generally suffers from a 2π phase ambiguity. The use of Bayesian inverse techniques, which aim to rigorously quantify model parameter uncertainty, have become widespread throughout seismology over the last decade. Here, we apply Bayesian inversion to measurements of surface-wave phase spectra in order to estimate 1-D, path-averaged Earth structure between station pairs. The dispersion curve and associated uncertainties are additional results of the inversion, which can then be used as input for subsequent analyses (e.g. tomography). We demonstrate this technique through application to surface-wave recordings from long-running seismic stations throughout western Canada. Our results for over 10 000 station pairs reveal first-order tectonic features consistent with previous studies, which provides confidence in our approach as well as an initial step towards resolving a full 3-D seismic velocity model for the region. This work also presents a foundation for the inversion of surface-wave phase spectra to estimate 3-D Earth structure directly. Finally, the ideas presented in this work are not limited to the inversion of surface-wave phase spectra, but can also be considered for Bayesian geophysical inversion of any circular quantities.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
University of Calgary, University of Ottawa, Natural Resources Canada (NRCan)
Journal
Geophysical Journal International
Volume
233
Pages
1387–1398
No. of pages
12
ISSN
0956-540X
DOI
https://doi.org/10.1093/gji/ggac506
Publication date
12-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
105122 Seismic
Keywords
ASJC Scopus subject areas
Geochemistry and Petrology, Geophysics
Portal url
https://ucrisportal.univie.ac.at/en/publications/5c606456-793b-4d77-84f6-b1895528dd2d