Point spread functions for earthquake source imaging: An interpretation based on seismic interferometry

Geophysical Journal International
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Abstract

Recently, various methods have been proposed and applied for earthquake source imaging, and theoretical relationships among the methods have been studied. In this study, we make a follow-up theoretical study to better understand the meanings of earthquake source imaging. For imaging problems, the point spread function (PSF) is used to describe the degree of blurring and degradation in an obtained image of a target object as a response of an imaging system. In this study, we formulate PSFs for earthquake source imaging. By calculating the PSFs, we find that waveform source inversion methods remove the effect of the PSF and are free from artifacts. However, the other source imaging methods are affected by the PSF and suffer from the effect of blurring and degradation due to the restricted distribution of receivers. Consequently, careful treatment of the effect is necessary when using the source imaging methods other than waveform inversions. Moreover, the PSF for source imaging is found to have a link with seismic interferometry with the help of the source-receiver reciprocity of Green’s functions. In particular, the PSF can be related to Green’s function for cases in which receivers are distributed so as to completely surround the sources. Furthermore, the PSF acts as a low-pass filter. Given these considerations, the PSF is quite useful for understanding the physical meaning of earthquake source imaging.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Point spread functions for earthquake source imaging: An interpretation based on seismic interferometry
Series title Geophysical Journal International
DOI 10.1093/gji/ggv109
Volume 202
Issue 1
Year Published 2015
Language English
Publisher Oxford University Press on behalf of The Royal Astronomical Society
Publisher location Oxford, United Kingdom
Contributing office(s) Volcano Science Center
Description 8 p.
First page 54
Last page 61
Online Only (Y/N) N
Additional Online Files (Y/N) N