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dc.contributor.authorMiyoshi, Takayuki
dc.contributor.authorObayashi, Masayuki
dc.contributor.authorPeter, Daniel
dc.contributor.authorTono, Yoko
dc.contributor.authorTsuboi, Seiji
dc.date.accessioned2017-10-05T12:47:09Z
dc.date.available2017-10-05T12:47:09Z
dc.date.issued2017-10-03
dc.identifier.citationMiyoshi T, Obayashi M, Peter D, Tono Y, Tsuboi S (2017) Adjoint tomography of the crust and upper mantle structure beneath the Kanto region using broadband seismograms. Progress in Earth and Planetary Science 4. Available: http://dx.doi.org/10.1186/s40645-017-0143-8.
dc.identifier.issn2197-4284
dc.identifier.doi10.1186/s40645-017-0143-8
dc.identifier.urihttp://hdl.handle.net/10754/625812
dc.description.abstractA three-dimensional seismic wave speed model in the Kanto region of Japan was developed using adjoint tomography for application in the effective reproduction of observed waveforms. Starting with a model based on previous travel time tomographic results, we inverted the waveforms obtained at seismic broadband stations from 140 local earthquakes in the Kanto region to obtain the P- and S-wave speeds Vp and Vs. Additionally, all centroid times of the source solutions were determined before the structural inversion. The synthetic displacements were calculated using the spectral-element method (SEM) in which the Kanto region was parameterized using 16 million grid points. The model parameters Vp and Vs were updated iteratively by Newton’s method using the misfit and Hessian kernels until the misfit between the observed and synthetic waveforms was minimized. Computations of the forward and adjoint simulations were conducted on the K computer in Japan. The optimized SEM code required a total of 6720 simulations using approximately 62,000 node hours to obtain the final model after 16 iterations. The proposed model reveals several anomalous areas with extremely low-Vs values in comparison with those of the initial model. These anomalies were found to correspond to geological features, earthquake sources, and volcanic regions with good data coverage and resolution. The synthetic waveforms obtained using the newly proposed model for the selected earthquakes showed better fit than the initial model to the observed waveforms in different period ranges within 5–30 s. This result indicates that the model can accurately predict actual waveforms.
dc.description.sponsorshipWe appreciate the valuable discussions we had with Kazuto Ando, Daisuke Suetsugu, and Nozomu Takeuchi. We used the seismic waveform and earthquake catalog provided by the NIED F-net. Digital map 50 m grid elevation data and the J-EGG500 were provided by the Geospatial Information Authority of Japan and the Japan Oceanographic Data Center, respectively. The large computing of the forward and adjoint simulations was conducted on the K computer at the RIKEN Advanced Institute for Computational Science in Kobe, Japan. We used the open source program package SPECFEM3D Cartesian and FLEXWIN from the Computational Infrastructure for Geodynamics (CIG; geodynamics.org) in this study. GMT software (Wessel and Smith 1998) was used to make most of the figures in this paper. This work was supported by the HPCI System Research project (Proposal number hp130013), JSPS KAKENHI Grant Number 16K21699, and MEXT KAKENHI Grant Number 15H05832.
dc.publisherSpringer Nature
dc.relation.urlhttp://link.springer.com/article/10.1186/s40645-017-0143-8
dc.rightsThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subjectSeismic wave speed model
dc.subjectAdjoint tomography
dc.subjectWaveform inversion
dc.subjectBroadband seismogram
dc.subjectKanto region
dc.titleAdjoint tomography of the crust and upper mantle structure beneath the Kanto region using broadband seismograms
dc.typeArticle
dc.contributor.departmentEarth Science and Engineering Program
dc.contributor.departmentExtreme Computing Research Center
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalProgress in Earth and Planetary Science
dc.eprint.versionPublisher's Version/PDF
dc.contributor.institutionEarthquake and Tsunami Research Division, National Research Institute for Earth Science and Disaster Resilience, 3-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan.
dc.contributor.institutionEarthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
dc.contributor.institutionDepartment of Deep Earth Structure and Dynamics Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
dc.contributor.institutionResearch and Development Bureau, Ministry of Education, Culture, Sports, Science and Technology, 3-2-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-8959, Japan.
dc.contributor.institutionCenter for Earth Information Science and Technology, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan.
kaust.personPeter, Daniel
refterms.dateFOA2018-06-14T04:31:03Z
dc.date.published-online2017-10-03
dc.date.published-print2017-12


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This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Except where otherwise noted, this item's license is described as This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.