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| Titel |
FrOsT: A new generation of normal mode seismology |
| VerfasserIn |
Andrew Valentine, David Al-Attar, Jeannot Trampert, John Woodhouse |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106591
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| Publikation (Nr.) |
 EGU/EGU2015-7315.pdf |
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| Zusammenfassung |
| Normal mode seismology provides important constraints on earth structure, particularly at the
largest spatial scales, and enables the imaging of density heterogeneities within the
Earth. In addition, computational approaches built upon normal modes offer an
efficient route towards obtaining synthetic seismograms and their sensitivity kernels
(partial derivatives of the seismograms with respect to source or structural model
parameters).
At present, it is difficult to compute normal modes at frequencies higher than around
100 mHz, and—as far as we are aware—no publicly-released codes can perform
complete calculations in 3D earth models. However, these are software limitations,
rather than inherent problems with the normal modes framework. We are therefore
developing the Free Oscillation Toolkit (FrOsT), a suite of software for normal mode
seismology designed to enable calculations for arbitrary 3D earth models, and to
arbitrarily high frequencies. All codes will be released on an open-source basis in due
course.
We demonstrate that improved radial integration and mode-counting techniques enable
stable calculations at high frequency, and present initial benchmarks in 1D earth models.
Through the use of the generalised spherical harmonic formalism, we show that it is
straightforward to obtain strain and rotation seismograms, in addition to displacement fields,
enabling a full range of data to be handled simultaneously. Finally, we provide an overview of
expected future developments, including software to compute complete seismograms in 3D
models through full mode coupling. |
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