Inference of thermodynamic state in the asthenosphere from anelastic properties, with applications to North American upper mantle

Evidence for Stress Localization Caused by Lithospheric Heterogeneity From Seismic Attenuation

“…Furthermore, although the temperature curves under different erosion rates modeled by Reiners and Brandon (2006) vary in the crust, the maximum temperature is always below 600 C°. At these temperatures, Qp of rocks is expected to be above 1,000 according to all current models for anelasticity (Havlin et al, 2021). Hence, the contribution to Δt* from the crust given above is likely to be an overestimate.…”

Seismic Attenuation at the Equatorial Mid‐Atlantic Ridge Constrained by Local Rayleigh Wave Analysis From the PI‐LAB Experiment

“…We also compared our results with the EPR (Yang et al, 2007), the Juan de Fuca Ridge (Ruan et al, 2018), old Pacific lithosphere (Ma et al, 2020), PREM (Dziewonski & Anderson, 1981), and a variety of oceanic ages from a global model (Dalton et al, 2008) (Figure 5). We have also examined the 𝐴𝐴 𝐴𝐴𝜇𝜇 and apparent Vs relationship of the present study and other studies of oceanic regions in comparison to four different experimental predictions (Jackson & Faul, 2010;McCarthy et al, 2011;Yamauchi & Takei, 2016) using the very broadband rheology calculator (Havlin et al, 2021) (Figure 6). The frequency dependence of shear attenuation in the lithosphere and asthenosphere from previously published results along with the results from the present study is shown in Figure 7…”

“…We choose two pressures, 1 GPa (about 32 km depth) and 2.5 GPa (about 82 km depth), to represent the lithosphere and the asthenosphere, respectively. We calculated the predicted 𝐴𝐴 𝐴𝐴𝜇𝜇 and Vs for a range of temperatures between 1,200-1,800°C and for a frequency range from 0.01-0.05 Hz, using the Very Broadband Rheology calculator (Havlin et al, 2021) assuming elastic coefficients appropriate for an olivine mantle (Figure 6a). We use the default settings in the calculations, which utilize the same coefficients and assumptions from the original published works.…”

“…Q μ −1 observations are particularly valuable because they provide complementary sensitivity to the more commonly constrained seismic velocity, providing additional insight, especially when combined with velocity. Experimental studies suggest that Vs and Q μ −1 should have a unique relationship with increasing Q μ −1 and decreasing Vs as temperature increases (Havlin et al, 2021;Jackson & Faul, 2010;McCarthy et al, 2011;Yamauchi & Takei, 2016). This relationship is also likely different for other parameters such as variable grain size, hydration, or partial melt (Havlin et al, 2021;Jackson & Faul, 2010;Karato & Park, 2019;McCarthy et al, 2011;Yamauchi & Takei, 2016).…”

Frequency Dependent Mantle Viscoelasticity via the Complex Viscosity: Cases From Antarctica

“…The appropriate length scale (sub-grain, or grain) that is the most appropriate for scaling, and the related parameter values, are still under debate. We refer the reader to Havlin et al (2021) for further discussion on these issues.…”