geodynamics / axisem

AxiSEM is a parallel spectral-element method to solve 3D wave propagation in a sphere with axisymmetric or spherically symmetric visco-elastic, acoustic, anisotropic structures.
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attenuation on transversely isotropic model #71

Open PengJX1023 opened 1 year ago

PengJX1023 commented 1 year ago

Hello, I found there is possible problem about the Lamé coefficients used to calculate attenuation of TI models.

when validating with AxiSEM3D, there is evident discrepency between waveforms for transversely isotropic model. image 2023-03-07_165053

At the begining of surface wave, there is about 5s misfit in phase because of different Lamé coefficients used in calculating attenuation. I think it' more reasonable to use Voigt average Lamé coefficients than only use horizontal velocities to calculate $\lambda$ and $\mu$. The dealing method doesn't affect Constitutive relation, but do influence attenuation calculation later.

image

The command is in get_models.F90 Lines 173. the related codes in def_precomp_terms.f90 should also be adjusted.