Insights into magma ocean dynamics from the transport properties of basaltic melt
The viscosity of magma plays a crucial role in the dynamics of the Earth: from the crystallization of a magma ocean during its initial stages to modern-day volcanic processes. However, the pressure-dependence behavior of viscosity at high pressure remains controversial. In this study, we report the results of first-principles molecular dynamics simulations of basaltic melt to show that the melt viscosity increases upon compression along each isotherm for the entire lower mantle after showing minima at ~6 GPa. However, elevated temperatures of the magma ocean translate to a narrow range of viscosity, i.e., 0.01-0.03 Pa.s. This low viscosity implies that the crystallization of the magma ocean could be complete within a few million years. These results also suggest that the crystallization of the magma ocean is likely to be fractional, thus supporting the hypothesis that present-day mantle heterogeneities could have been generated during the early crystallization of the primitive mantle.
Publication Source (Journal or Book title)
Bajgain, S. K., Ashley, A. W., Mookherjee, M., Ghosh, D. B., & Karki, B. B. (2022). Insights into magma ocean dynamics from the transport properties of basaltic melt. Nature communications, 13 (1), 7590. https://doi.org/10.1038/s41467-022-35171-y