English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/95118
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Multiscale full waveform inversion

AutorFichtner, Andreas; Trampert, Jeannot; Cupillard, Paul; Saygin, Erdinc; Taymaz, Tuncay; Capdeville, Yann; Villaseñor, Antonio
Palabras claveInverse theory
Seismic anisotropy
Seismic tomography
Computational seismology
Theoretical seismology
Wave propagation
Fecha de publicaciónfeb-2013
EditorOxford University Press
CitaciónGeophysical Journal International 194: 534-556 (2013)
ResumenWe develop and apply a full waveform inversion method that incorporates seismic data on a widerangeofspatio-temporalscales,therebyconstrainingthedetailsofbothcrustalandupper- mantle structure. This is intended to further our understanding of crust–mantle interactions that shape the nature of plate tectonics, and to be a step towards improved tomographic models of strongly scale-dependent earth properties, such as attenuation and anisotropy. The inversion for detailed regional earth structure consistently embedded within a large- scale model requires locally refined numerical meshes that allow us to (1) model regional wave propagation at high frequencies, and (2) capture the inferred fine-scale heterogeneities. The smallest local grid spacing sets the upper bound of the largest possible time step used to iteratively advance the seismic wave field. This limitation leads to extreme computational costs in the presence of fine-scale structure, and it inhibits the construction of full waveform tomographic models that describe earth structure on multiple scales. To reduce computational requirements to a feasible level, we design a multigrid approach based on the decomposition of a multiscale earth model with widely varying grid spacings into a family of single-scale models where the grid spacing is approximately uniform. Each of the single-scale models contains a tractable number of grid points, which ensures computational efficiency. The multi-to-single- scale decomposition is the foundation of iterative, gradient-based optimization schemes that simultaneously and consistently invert data on all scales for one multi-scale model. We demonstrate the applicability of our method in a full waveform inversion for Eurasia, with a special focus on Anatolia where coverage is particularly dense. Continental-scale structure is constrained by complete seismic waveforms in the 30–200 s period range. In addition to the well-known structural elements of the Eurasian mantle, our model reveals a variety of subtle features, such as the Armorican Massif, the Rhine Graben and the Massif Central. Anatolia is covered by waveforms with 8–200 s period, meaning that the details of both crustal and mantle structure are resolved consistently. The final model contains numerous previously undiscovered structures, including the extension-related updoming of lower-crustal material beneath the Menderes Massif in western Anatolia. Furthermore, the final model for the Anatolian region confirms estimates of crustal depth fromreceiverfunctionanalysis,anditaccuratelyexplainscross-correlationsofambientseismic noise at 10 s period that have not been used in the tomographic inversion. This provides strong independent evidence that detailed 3-D structure is well resolved.
Versión del editorhttp://dx.doi.org/ 10.1093/gji/ggt118
Aparece en las colecciones: (ICTJA) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Villaseñor Geophys J Int 194 534.pdf8,18 MBAdobe PDFVista previa
Mostrar el registro completo

Artículos relacionados:

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.