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dc.contributor.author
Blom, Nienke
dc.contributor.author
Fichtner, Andreas
dc.contributor.author
Boehm, Christian
dc.date.accessioned
2017-11-13T16:39:02Z
dc.date.available
2017-09-05T11:22:48Z
dc.date.available
2017-09-05T17:05:32Z
dc.date.available
2017-09-05T17:19:01Z
dc.date.available
2017-11-13T16:39:02Z
dc.date.issued
2017-05
dc.identifier.issn
0956-540X
dc.identifier.issn
1365-246X
dc.identifier.other
10.1093/gji/ggx076
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/183054
dc.identifier.doi
10.3929/ethz-b-000183054
dc.description.abstract
Density variations drive mass transport in the Earth from plate tectonics to convection in the mantle and core. Nevertheless, density remains poorly known because most geophysical measurements used to probe the Earth's interior either have little sensitivity to density, suffer from trade-offs or from non-uniqueness. With the ongoing expansion of computational power, it has become possible to accurately model complete seismic wavefields in a 3-D heterogeneous Earth, and to develop waveform inversion techniques that account for complicated wavefield effects. This may help to improve resolution of density. Here, we present a pilot study where we explore the extent to which waveform inversion may be used to better recover density as a separate, independent parameter. We perform numerical simulations in 2-D to investigate under which conditions, and to what extent density anomalies may be recovered in the Earth's mantle. We conclude that density can indeed be constrained by seismic waveforms, mainly as a result of scattering effects at density contrasts. As a consequence, the low-frequency part of the wavefield is the most important for constraining the actual extent of anomalies. While the impact of density heterogeneities on the wavefield is small compared to the effects of velocity variations, it is likely to be detectable in modern regional- to global-scale measurements. We also conclude that the use of gravity data as additional information does not help to further improve the recovery of density anomalies unless strong a priori constraints on the geometry of density variations are applied. This is a result of the inherent physical non-uniqueness of potential-field inverse problems. Finally, in the limited numerical setup that we employ, we find that the initially supplied anomalies in S- and P-velocity models are of minor importance.
en_US
dc.language.iso
en
en_US
dc.publisher
Oxford University Press
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/4.0/
dc.subject
Gravity anomalies and Earth structure
en_US
dc.subject
Inverse theory
en_US
dc.subject
Waveform inversion
en_US
dc.subject
Seismic tomography
en_US
dc.subject
Wave propagation
en_US
dc.subject
Wave scattering and diffraction
en_US
dc.title
Synthetic inversions for density using seismic and gravity data
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 4.0 International
dc.date.published
2017-03-01
ethz.journal.title
Geophysical Journal International
ethz.journal.volume
209
en_US
ethz.journal.issue
2
en_US
ethz.journal.abbreviated
Geophys. j. int.
ethz.pages.start
1204
en_US
ethz.pages.end
1220
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.publication.place
Oxford
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02330 - Dep. Erdwissenschaften / Dep. of Earth Sciences::02506 - Institut für Geophysik / Institute of Geophysics::03971 - Fichtner, Andreas / Fichtner, Andreas
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02330 - Dep. Erdwissenschaften / Dep. of Earth Sciences::02506 - Institut für Geophysik / Institute of Geophysics::03971 - Fichtner, Andreas / Fichtner, Andreas
en_US
ethz.date.deposited
2017-09-05T11:22:48Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-09-05T17:05:38Z
ethz.rosetta.lastUpdated
2018-11-06T01:12:22Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
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