Publication Date:
2017-04-04
Description:
The representation of crustal structure in 3D numerical models often poses particular problems that are difficult to overcome.
Practical implementations of an improved crustal model into efficient tools for seismic wave propagation modeling often fail to honor the strongly varying depth of the Moho discontinuity. The widely used Spectral Element Method (SEM) using hexahedral elements follows the compromise to approximate this undulating discontinuity with polynomials inside the elements.
This solution is satisfactory when modeling seismic wave propagation on the global scale and limitedly to rather low frequencies, but may induce inaccuracies or artifacts when working at the continental scale, where propagation distances are in the order of a few hundred or thousand kilometers and frequencies of interest are up to 0.1 Hz.
An alternative modeling tool for seismic wave propagation simulations is the Discontinuous Galerkin Finite Element Method (ADER-DG) that achieves high-order accuracy in space and time using fully unstructured tetrahedral meshes. With this approach strong and undulating discontinuities can be considered more easily by the mesh and modifications of the geometrical properties can be carried out rapidly due to an external mesh generation process.
Therefore, we implement more realistic models for the European crust -- based on a new, comprehensive compilation of currently available information from diverse sources, ranging from seismic prospection to receiver functions studies -- in both, the SEM and ADER-DG codes, to study the effects of the numerical representation of crustal structures on seismic wave propagation modeling.
We compare the results of the different methods and implementation strategies with respect to accuracy and performance.
Clearly, an improved knowledge and detailed representation of the structure of the Earth's crust is a key requisite for better imaging of the mantle structure.
Description:
Published
Description:
San Francisco, California, USA
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
open
Keywords:
crust
;
wave propagation
;
ADER-DG
;
SEM method
;
Europe
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
;
04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Poster session
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