Bijaya B . Karki , Conditions : Implications for an Early Magma Ocean Liquid at Earth ’ s Mantle 3 Viscosity of MgSiO

Evidence of denser MgSiO3 glass above 133 gigapascal (GPa) and implications for remnants of ultradense silicate melt from a deep magma ocean.

Ultralow velocity zones are the largest seismic anomalies in the mantle, with 10-30% seismic velocity reduction observed in thin layers less than 20-40 km thick, just above the Earth's core-mantle boundary (CMB). The presence of silicate melts, possibly a remnant of a deep magma ocean in the early Earth, have been proposed to explain ultralow velocity zones. It is, however, still an open questi...

Structure and density of basaltic melts at mantle conditions from first-principles simulations

The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our result...

Shear viscosity and diffusion in liquid MgSiO 3 : Transport properties and implications for 2 terrestrial planet magma oceans 3

Transport properties of carbonated silicate melt at high pressure

Carbon dioxide, generally considered as the second most abundant volatile component in silicate magmas, is expected to significantly influence various melt properties. In particular, our knowledge about its dynamical effects is lacking over most of Earth's mantle pressure regime. Here, we report the first-principles molecular dynamics results on the transport properties of carbonated MgSiO3 liq...

Shear viscosity and diffusion in liquid MgSiO3: Transport properties and implications for terrestrial planet magma oceans

Molecular dynamics simulations using a pair-wise additive potential are implemented to investigate self-diffusion (Mg, Si, and O) and shear viscosity of liquid MgSiO3 in the density-temperaturepressure range 2350–5300 kg/m3, 2500–5000 K, and 0–140 GPa, respectively. Self-diffusivity and shear viscosity are described by modified Arrhenian expressions, which feature a pressure-dependent activatio...