Title: Balancing unevenly distributed data in seismic tomography: a global adjoint tomography example

Abstract

SUMMARY The uneven distribution of earthquakes and stations in seismic tomography leads to slower convergence of nonlinear inversions and spatial bias in inversion results. Including dense regional arrays, such as USArray or Hi-Net, in global tomography causes severe convergence and spatial bias problems, against which conventional pre-conditioning schemes are ineffective. To save computational cost and reduce model bias, we propose a new strategy based on a geographical weighting of sources and receivers. Unlike approaches based on ray density or the Voronoi tessellation, this method scales to large full-waveform inversion problems and avoids instabilities at the edges of dense receiver or source clusters. We validate our strategy using a 2-D global waveform inversion test and show that the new weighting scheme leads to a nearly twofold reduction in model error and much faster convergence relative to a conventionally pre-conditioned inversion. We implement this geographical weighting strategy for global adjoint tomography.

Authors:

Ruan, Youyi  ^[1];

• Search DOE PAGES for author "Ruan, Youyi"
• Search DOE PAGES for ORCID "0000-0002-5691-6670"

Lei, Wenjie ^[2]; Modrak, Ryan ^[3]; Örsvuran, Rıdvan ^[4]; Bozdağ, Ebru ^[5]; Tromp, Jeroen  ^[6]

• Search DOE PAGES for author "Tromp, Jeroen"
• Search DOE PAGES for ORCID "0000-0002-2742-8299"

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+ Show Author Affiliations

1. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China, Department of Geosciences, Princeton University, Princeton, NJ 08520, USA
2. Department of Geosciences, Princeton University, Princeton, NJ 08520, USA
3. Department of Geosciences, Princeton University, Princeton, NJ 08520, USA, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
4. Laboratoire Géoazur, Université Côte d’Azur, Valbonne 06560, France
5. Department of Geophysics, Colorado School of Mines, Golden, CO 80401, USA
6. Department of Geosciences, Princeton University, Princeton, NJ 08520, USA, Program in Applied & Computational Mathematics, Princeton University, Princeton, NJ 08520, USA

Publication Date:

Thu Aug 01 00:00:00 EDT 2019

Sponsoring Org.:

USDOE

OSTI Identifier:

1562774

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Published Article

Journal Name:

Geophysical Journal International

Additional Journal Information:

Journal Name: Geophysical Journal International Journal Volume: 219 Journal Issue: 2; Journal ID: ISSN 0956-540X

Publisher:

Oxford University Press

Country of Publication:

United Kingdom

Language:

English