MD simulations with pairwise potential on MgO and MgSiO3 vacancies pair were conducted to obtain the Newtonian viscosity of lower mantle. The results of MgO are such that the viscosity of the upper half portion in the lower mantle shows uniform structure but in the lower half it rapidly decreases to the core mantle boundary by two order of magnitude. On the other hand, the viscosity of MgSiO3 p...

Paleomagnetic data provide one of the few probes available to interrogate early evolution of the core. Here we apply this probe by examining the latitudinal dependence of paleosecular variation (PSV) data derived from high-quality paleomagnetic data collected from Proterozoic and Neoarchean rocks. These data define a Neoarchean geomagnetic field that was more dipolar than that during Proterozoi...

The surface of Mars consists of an old, heavily cratered and elevated southern hemisphere and younger, resurfaced and depressed northern hemisphere, a feature often termed the crustal dichotomy. The global crustal structure [Zuber et al., 2000] revealed by topography and gravity data from the Mars Global Surveyor spacecraft, and the possible late formation of the boundary zone between the hemis...

Paleomagnetic data provide one of the few probes available to interrogate early evolution of the core. Here we apply this probe by examining the latitudinal dependence of paleosecular variation (PSV) data derived from high-quality paleomagnetic data collected from Proterozoic and Neoarchean rocks. These data define a Neoarchean geomagnetic field that was more dipolar than that during Proterozoi...

"Lithosphere" is a mechanical concept implying strength and relative permanence. Unfortunately, the term has also been applied to the surface thermal boundary layer (TBL) and a shallow enriched geochemical reservoir, features having nothing to do with strength. The "strong" lithosphere is about one half the thickness of the TBL. The bottom of the elastic plate, the maximum depths of midplate an...

It has been claimed that focused hot cylindrical upwelling plumes cause many of the surface volcanic hotspots on Earth. It has also been argued that they must originate from thermal boundary layers. In this paper, we present spherical simulations of mantle circulation at close to Earth-like vigor with significant internal heating. These show, in addition to thermal boundary layer plumes, a new ...

The core mantle boundary (CMB) separates Earth's liquid iron outer core from the solid but slowly convecting mantle. The detailed structure and dynamics of the mantle within ~300 km of this interface remain enigmatic: it is a complex region, which exhibits thermal, compositional and phase-related heterogeneity, isolated pockets of partial melt and strong variations in seismic velocity and aniso...

Long intervals of single geomagnetic polarity (superchrons) reflect geodynamo processes, driven by core-mantle boundary interactions; however, it is not clear what initiates the start and end of superchrons, other than superchrons probably reflect lower heat flow across the core-mantle boundary compared with adjacent intervals. Here geomagnetic polarity timescales, with confidence intervals, ar...