Water distribution across the mantle transition zone and its implications for global material circulation

The influence of the transition zone water filter on convective circulation in the mantle

[1] The ‘‘transition zone water filter’’ model of mantle convection attempts to reconcile geochemical evidence for isolated mantle reservoirs with geophysical evidence for whole mantle circulation by decoupling incompatible elements from bulk mantle circulation via a melt layer above the 410 km discontinuity. This would result in a stratified heating distribution similar to layered convection m...

The Transition-Zone Water Filter Model for Global Material Circulation: Where Do We Stand?

Materials circulation in Earth’s mantle will be modified if partial melting occurs in the transition zone. Melting in the transition zone is plausible if a significant amount of incompatible components is present in Earth’s mantle. We review the experimental data on melting and melt density and conclude that melting is likely under a broad range of conditions, although conditions for dense melt...

Comparisons between seismic Earth structures and mantle flow models based on radial correlation functions.

Three-dimensional numerical simulations were conducted of mantle convection in which flow through the transition zone is impeded by either a strong chemical change or an endothermic phase change. The temperature fields obtained from these models display a well-defined minimum in the vertical correlation length at or near the radius where the barrier is imposed, even when the fields were filtere...

Whole-Mantle Convection and the Transition-Zone Water Filter D. Bercovici & S. Karato

In the transition-zone water-filter hypothesis, (see main text), water is assumed essentially trapped within the transition zone because of dehydration melting of ambient upwelling at 410km and exsolution of water from slabs at 660km. The assumption that recycling of water is closed allows us to develop a simple theoretical model with which to predict various important parameters such as the me...

Global variations of temperature and water content in the mantle transition zone from higher mode surface waves