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An SEM-DSM three-dimensional hybrid method for modelling teleseismic waves with complicated source-side structures

Wu, Wenbo and Ni, Sidao and Zhan, Zhongwen and Wei, Shengji (2018) An SEM-DSM three-dimensional hybrid method for modelling teleseismic waves with complicated source-side structures. Geophysical Journal International, 215 (1). pp. 133-154. ISSN 0956-540X. https://resolver.caltech.edu/CaltechAUTHORS:20181108-084800675

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Abstract

Despite recent advances in High Performance Computing (HPC), numerical simulation of high frequency (e.g. 1 Hz or higher) seismic wave propagation at the global scale is still prohibitive. To overcome this difficulty, we propose a hybrid method to efficiently compute teleseismic waveforms with 3-D source-side structures. By coupling the Spectral Element Method (SEM) with the Direct Solution Method (DSM) based on the representation theorem, we are able to limit the costly SEM simulation to a small source-side region and avoid computation over the entire space of the Earth. Our hybrid method is benchmarked against 1-D DSM synthetics and 3-D SEM synthetics. We also discuss numerical difficulties in the implementation, including slow DSM convergence near source depth, discretization error, Green’s function interpolation and local 3-D wavefield approximations. As a case study, we apply our hybrid method to two subduction earthquakes and show its advantage in understanding 3-D source-side effects on teleseismic P-waves. Our hybrid method reduces computational cost by more than two orders of magnitude when only source-side 3-D complexities are of concern. Thus our hybrid method is useful for a series of problems in seismology, such as imaging 3-D structures of a subducting slab or a mid-ocean ridge and studying source parameters with 3-D source-side complexities using teleseismic waveforms.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1093/gji/ggy273DOIArticle
ORCID:
AuthorORCID
Wu, Wenbo0000-0002-6249-8065
Ni, Sidao0000-0003-2988-4850
Zhan, Zhongwen0000-0002-5586-2607
Additional Information:© The Author(s) 2018. Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices). Accepted 2018 July 5. Received 2018 January 7; in original form 2018 June 30. Published: 07 July 2018. We are grateful for reviews from Sébastien Chevrot and another anonymous reviewer which helped to improve the manuscript. We thank Joel D. Simon and Frederik J. Simons for suggestions to improve this manuscript. We are thankful to Nozomu Takeuchi for providing the DSM software (http://www.eri.u-tokyo.ac.jp/people/takeuchi/software/index.html). Our code will be posted on https://github.com/wenbowu-geo. This work was supported by funding from National Basic Research Program of China (973 Program) through grant 2014CB845901. SW is supported by the internal grant (M4430255) of Earth Observatory of Singapore. The authors acknowledge the use of the GMT (Wessel & Smith 1998) and SAC (Goldstein et al.2003) software packages. The seismic waveform data used in this study were obtained from the Incorporated Research Institutions for Seismology (IRIS) Data Management Center(http://dx.doi.org/doi:10.7914/SN/II).
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
National Basic Research Program of China2014CB845901
Earth Observatory of SingaporeM4430255
Subject Keywords:wave propagation; body waves; computational seismology; earthquake dynamics; seismicity and tectonics
Issue or Number:1
Record Number:CaltechAUTHORS:20181108-084800675
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20181108-084800675
Official Citation:Wenbo Wu, Sidao Ni, Zhongwen Zhan, Shengji Wei; An SEM-DSM three-dimensional hybrid method for modelling teleseismic waves with complicated source-side structures, Geophysical Journal International, Volume 215, Issue 1, 1 October 2018, Pages 133–154, https://doi.org/10.1093/gji/ggy273
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90741
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:08 Nov 2018 21:05
Last Modified:09 Mar 2020 13:19

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