Foundations for a multiscale collaborative Earth model

Handle URI:
http://hdl.handle.net/10754/592834
Title:
Foundations for a multiscale collaborative Earth model
Authors:
Afanasiev, M.; Peter, Daniel ( 0000-0002-3397-5379 ) ; Sager, K.; Simut, S.; Ermert, L.; Krischer, L.; Fichtner, A.
Abstract:
We present a computational framework for the assimilation of local to global seismic data into a consistent model describing Earth structure on all seismically accessible scales. This Collaborative Seismic Earth Model (CSEM) is designed to meet the following requirements: (i) Flexible geometric parametrization, capable of capturing topography and bathymetry, as well as all aspects of potentially resolvable structure, including small-scale heterogeneities and deformations of internal discontinuities. (ii) Independence of any particular wave equation solver, in order to enable the combination of inversion techniques suitable for different types of seismic data. (iii) Physical parametrization that allows for full anisotropy and for variations in attenuation and density. While not all of these parameters are always resolvable, the assimilation of data that constrain any parameter subset should be possible. (iv) Ability to accommodate successive refinements through the incorporation of updates on any scale as new data or inversion techniques become available. (v) Enable collaborative Earth model construction. The structure of the initial CSEM is represented on a variable-resolution tetrahedral mesh. It is assembled from a long-wavelength 3-D global model into which several regional-scale tomographies are embedded. We illustrate the CSEM workflow of successive updating with two examples from Japan and the Western Mediterranean, where we constrain smaller scale structure using full-waveform inversion. Furthermore, we demonstrate the ability of the CSEM to act as a vehicle for the combination of different tomographic techniques with a joint full-waveform and traveltime ray tomography of Europe. This combination broadens the exploitable frequency range of the individual techniques, thereby improving resolution. We perform two iterations of a whole-Earth full-waveform inversion using a long-period reference data set from 225 globally recorded earthquakes. At this early stage of the CSEM development, the broad global updates mostly act to remove artefacts from the assembly of the initial CSEM. During the future evolution of the CSEM, the reference data set will be used to account for the influence of small-scale refinements on large-scale global structure. The CSEM as a computational framework is intended to help bridging the gap between local, regional and global tomography, and to contribute to the development of a global multiscale Earth model. While the current construction serves as a first proof of concept, future refinements and additions will require community involvement, which is welcome at this stage already.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Foundations for a multiscale collaborative Earth model 2015, 204 (1):39 Geophysical Journal International
Publisher:
Oxford University Press (OUP)
Journal:
Geophysical Journal International
Issue Date:
11-Nov-2015
DOI:
10.1093/gji/ggv439
Type:
Article
ISSN:
0956-540X; 1365-246X
Additional Links:
http://gji.oxfordjournals.org/cgi/doi/10.1093/gji/ggv439
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorAfanasiev, M.en
dc.contributor.authorPeter, Danielen
dc.contributor.authorSager, K.en
dc.contributor.authorSimut, S.en
dc.contributor.authorErmert, L.en
dc.contributor.authorKrischer, L.en
dc.contributor.authorFichtner, A.en
dc.date.accessioned2016-01-05T07:23:23Zen
dc.date.available2016-01-05T07:23:23Zen
dc.date.issued2015-11-11en
dc.identifier.citationFoundations for a multiscale collaborative Earth model 2015, 204 (1):39 Geophysical Journal Internationalen
dc.identifier.issn0956-540Xen
dc.identifier.issn1365-246Xen
dc.identifier.doi10.1093/gji/ggv439en
dc.identifier.urihttp://hdl.handle.net/10754/592834en
dc.description.abstractWe present a computational framework for the assimilation of local to global seismic data into a consistent model describing Earth structure on all seismically accessible scales. This Collaborative Seismic Earth Model (CSEM) is designed to meet the following requirements: (i) Flexible geometric parametrization, capable of capturing topography and bathymetry, as well as all aspects of potentially resolvable structure, including small-scale heterogeneities and deformations of internal discontinuities. (ii) Independence of any particular wave equation solver, in order to enable the combination of inversion techniques suitable for different types of seismic data. (iii) Physical parametrization that allows for full anisotropy and for variations in attenuation and density. While not all of these parameters are always resolvable, the assimilation of data that constrain any parameter subset should be possible. (iv) Ability to accommodate successive refinements through the incorporation of updates on any scale as new data or inversion techniques become available. (v) Enable collaborative Earth model construction. The structure of the initial CSEM is represented on a variable-resolution tetrahedral mesh. It is assembled from a long-wavelength 3-D global model into which several regional-scale tomographies are embedded. We illustrate the CSEM workflow of successive updating with two examples from Japan and the Western Mediterranean, where we constrain smaller scale structure using full-waveform inversion. Furthermore, we demonstrate the ability of the CSEM to act as a vehicle for the combination of different tomographic techniques with a joint full-waveform and traveltime ray tomography of Europe. This combination broadens the exploitable frequency range of the individual techniques, thereby improving resolution. We perform two iterations of a whole-Earth full-waveform inversion using a long-period reference data set from 225 globally recorded earthquakes. At this early stage of the CSEM development, the broad global updates mostly act to remove artefacts from the assembly of the initial CSEM. During the future evolution of the CSEM, the reference data set will be used to account for the influence of small-scale refinements on large-scale global structure. The CSEM as a computational framework is intended to help bridging the gap between local, regional and global tomography, and to contribute to the development of a global multiscale Earth model. While the current construction serves as a first proof of concept, future refinements and additions will require community involvement, which is welcome at this stage already.en
dc.language.isoenen
dc.publisherOxford University Press (OUP)en
dc.relation.urlhttp://gji.oxfordjournals.org/cgi/doi/10.1093/gji/ggv439en
dc.rightsThis article has been accepted for publication in Geophysical Journal International ©: 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.en
dc.subjectInverse theoryen
dc.subjectSeismic tomographyen
dc.subjectComputational seismologyen
dc.subjectWave propagationen
dc.titleFoundations for a multiscale collaborative Earth modelen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalGeophysical Journal Internationalen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Earth Sciences, Institute of Geophysics, ETH Zurich, Zurich, Switzerlanden
dc.contributor.institutionInstitute of Computational Sciences, Advanced Computing Laboratory, Universita della Svizzera Italiana, Lugano, Switzerlanden
dc.contributor.institutionDepartment of Earth and Environmental Sciences, Institute of Geophysics, Ludwig Maximilian University, Munich, Germanyen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorPeter, Danielen
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