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| Titel |
MC Kernel: Broadband Waveform Sensitivity Kernels for Seismic Tomography |
| VerfasserIn |
Simon C. Stähler, Martin van Driel, Ludwig Auer, Kasra Hosseini, Karin Sigloch, Tarje Nissen-Meyer |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250127177
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| Publikation (Nr.) |
 EGU/EGU2016-7020.pdf |
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| Zusammenfassung |
| We present MC Kernel, a software implementation to calculate seismic sensitivity kernels on
arbitrary tetrahedral or hexahedral grids across the whole observable seismic frequency
band.
Seismic sensitivity kernels are the basis for seismic tomography, since they map
measurements to model perturbations. Their calculation over the whole frequency range was
so far only possible with approximative methods (Dahlen et al. 2000). Fully numerical
methods were restricted to the lower frequency range (usually below 0.05 Hz, Tromp et al.
2005). With our implementation, it’s possible to compute accurate sensitivity kernels for
global tomography across the observable seismic frequency band. These kernels rely on
wavefield databases computed via AxiSEM (www.axisem.info), and thus on spherically
symmetric models. The advantage is that frequencies up to 0.2 Hz and higher can be
accessed.
Since the usage of irregular, adapted grids is an integral part of regularisation in seismic
tomography, MC Kernel works in a inversion-grid-centred fashion: A Monte-Carlo
integration method is used to project the kernel onto each basis function, which allows to
control the desired precision of the kernel estimation. Also, it means that the code
concentrates calculation effort on regions of interest without prior assumptions on the kernel
shape. The code makes extensive use of redundancies in calculating kernels for different
receivers or frequency-pass-bands for one earthquake, to facilitate its usage in large-scale
global seismic tomography. |
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