17:15 〜 19:15
[PPS08-P16] Comparison of the differences between viscoelastic models on solid tide frequency and seismic frequency.
キーワード：Moon, Solid tide, viscoelastic model, tidal response
The existence of a partially molten S-wave-attenuating layer (i.e. the low-viscosity layer) at the base of the lunar mantle is a topic of long-standing debate. The choice of viscoelastic models is one of the key factor when using the tidal response to study the issue. Previous study showed that applying the Maxwell model to the lunar interior supports the existence of a partially molten layer, whereas the existence of this layer is unnecessary with a more complex viscoelastic model (e.g., the extended Burgers model or the Sundberg-Cooper model). However, the torsional force oscillation experiment concluded that the Maxwell model would underestimate the dissipation of olivine, suggesting that the Maxwell model may have some inapplicability when applied to the Moon. The problem is that viscoelastic models may not be able to simultaneously satisfy the experimental data for short periods as well as the viscoelastic response for long solid tide periods.
We investigate the effect of various parameters (both empirical as well as experimental) in the different viscoelastic models on the theoretical dissipations from short to long period. For viscoelastic model, we used the Maxwell model, the Power-law model, the extended Burgers model, the Andrade models with different type of dimensionless Andrade time ζ (=τA/τM), the Sundberg-Cooper models with different type of relaxation time function D(τ). The results show that with the ζ increasing, the dissipation of the Sundberg-Cooper model on monthly and annual period converge to the Maxwell model’s dissipation, still having similarity dissipation to the experimental data on short period. This suggests that it is possible for the Sundberg-Cooper model to meet the short-period laboratory data while producing a solid tidal response consistent with observations when applied to the Moon.
We investigate the effect of various parameters (both empirical as well as experimental) in the different viscoelastic models on the theoretical dissipations from short to long period. For viscoelastic model, we used the Maxwell model, the Power-law model, the extended Burgers model, the Andrade models with different type of dimensionless Andrade time ζ (=τA/τM), the Sundberg-Cooper models with different type of relaxation time function D(τ). The results show that with the ζ increasing, the dissipation of the Sundberg-Cooper model on monthly and annual period converge to the Maxwell model’s dissipation, still having similarity dissipation to the experimental data on short period. This suggests that it is possible for the Sundberg-Cooper model to meet the short-period laboratory data while producing a solid tidal response consistent with observations when applied to the Moon.