Melting and density of MgSiO3 determined by shock compression of bridgmanite to 1254GPa

The essential data for interior and thermal evolution models of the Earth and super-Earths are the density and melting of mantle silicate under extreme conditions. Here, we report an unprecedently high melting temperature of MgSiO3 at 500GPa by direct shockwave loading of pre-synthesized dense MgSiO3 (bridgmanite) using the Z Pulsed Power Facility. We also present the first high-precision density data of crystalline MgSiO3 to 422GPa and 7200K and of silicate melt to 1254GPa. The experimental density measurements support our density functional theory based molecular dynamics calculations, providing benchmarks for theoretical calculations under extreme conditions. The excellent agreement between experiment and theory provides a reliable reference density profile for super-Earth mantles. Furthermore, the observed upper bound of melting temperature, 9430K at 500GPa, provides a critical constraint on the accretion energy required to melt the mantle and the prospect of driving a dynamo in massive rocky planets. The authors here report high melting temperatures of MgSiO3 at 500GPa by direct shockwave loading of pre-synthesized dense bridgemanite. This is essential data to understand the thermal evolution of the interiors of terrestrial (exo-)planets.

Automated summary

The research reports high melting temperatures of MgSiO3 at 500 GPa, providing important data for understanding the thermal evolution of the interiors of Earth and super-Earths.