 |
| Titel |
Going to high frequency for full waveform inversion of teleseismic wavefields based upon a SEM-DSM hybrid method and massive High-Performance Computing |
| VerfasserIn |
Dimitri Komatitsch, Vadim Monteiller, Sébastien Chevrot, Yi Wang, Clément Durochat |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250108130
|
| Publikation (Nr.) |
 EGU/EGU2015-7863.pdf |
|
|
|
|
|
| Zusammenfassung |
| We present a method for high-resolution imaging of lithospheric structures based on full
waveform inversion of teleseismic wavefields. We model the propagation of seismic waves
using our recently developed Direct Solution Method (DSM) / Spectral-Element Method
(SEM) hybrid technique, which allows us to simulate the propagation of short period
teleseismic waves through a regional 3-D model.
We implement an iterative quasi-Newton method based upon the L-BFGS algorithm, with a
gradient of the misfit function computed with the adjoint-state method. Compared to gradient
or conjugate-gradient methods, the L-BFGS algorithm finds solutions that better explain the
observed waveforms, and at a much faster convergence rate.
We illustrate the potential of this method on a synthetic test case that consists in a crustal
model with a crustal discontinuity at 25 km depth and a sharp Moho jump. This simple
model contains short and long wavelength heterogeneities along both the lateral and vertical
dimensions.
In order to do that successfully we resort to high-performance computing on supercomputing
clusters using an improved version of our SPECFEM3D open-source software package,
which exhibits excellent scalability on parallel machines. |
|
|
|
|
|
|