Viscosity of hydrous rhyolitic melts inferred from kinetic experiments, and a new viscosity model

Viscosity of hydrous silicate melts is essential in modeling the dynamics of magma transport and volcanic eruptions. Numerous experimental measurements of viscosity, as well as viscosity models, have been published. For general melt compositions, the classic models of either Bottinga and Weill (1972) or Shaw (1972) are still used, not because they are reliable, but because of the extreme difficulty in calibrating something better (Lange 1994). For specific melt compositions, more advanced models and relations have been developed (e.g., Richet 1984; Richet et al. 1986, 1996; Hess and Dingwell 1996; Scaillet et al. 1996; Schulze et al. 1996; Dingwell et al. 1998a,