Kinematic earthquake rupture inversion in the frequency domain

TitleKinematic earthquake rupture inversion in the frequency domain
Publication TypeJournal Article
Year of Publication2014
AuthorsFan W.Y, Shearer PM, Gerstoft P
JournalGeophysical Journal International
Date Published2014/11
Type of ArticleArticle
ISBN Number0956-540X
Accession NumberWOS:000343411700036
Keywords1979 imperial-valley; 2003 tokachi-oki; bayesian; california; earthquake; Earthquake ground motions; finite fault earthquake; Fourier analysis; Inverse theory; inversion; japan earthquake; joint inversion; source models; source observations; strong ground motion; support-operator method

We develop a frequency-based approach to earthquake slip inversion that requires no prior information on the rupture velocity or slip-rate functions. Because the inversion is linear and is performed separately at each frequency, it is computationally efficient and suited to imaging the finest resolvable spatial details of rupture. We demonstrate the approach on synthetic seismograms based on the Source Inversion Validation Exercise 1 (SIV1) of a crustal M-w 6.6 strike-slip earthquake recorded locally. A robust inversion approach is obtained by applying a combination of damping, smoothing and forcing zero slip at the edge of the fault model. This approach achieves reasonable data fits, overall agreement to the SIV1 model, including slip-rate functions of each subfault, from which its total slip, slip time history and rupture velocity can be extracted. We demonstrate the method's robustness by exploring the effects of noise, random timing errors, and fault geometry errors. The worst effects on the inversion are seen from errors in the assumed fault geometry.

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