Hydrous phases are stabilized in the oceanic crust through constant interaction between the lithosphere and the overlying hydrosphere. These hydrous phases lock up substantial amounts of water and, over geological time scale, play a significant role in influencing the global sea-level. Subduction zones, which are major tectonic features, transport water into the Earth's interior. The efficiency of the transport of water and the extent of mantle hydration are intimately linked with the thermodynamic stability and thermoelasticity of hydrous phases. Since water has considerable effects on melting and on the elastic and transport properties of the Solid Earth, it is important to constrain the degree of mantle hydration.
This research attempts to put more accurate constraints on the transport of water into the Earth's interior and on mantle hydration. It will contribute to scientific understanding of the crystal structure, thermodynamics, equation of state, and elasticity of various hydrous phases that are likely to be stabilized in subduction zone settings. It will relate the energetics and thermoelasticity of hydrous phases with the following aspects: transport of water into the Earth's interior; extent of mantle hydration; observed low velocity layers; and large anisotropy in subduction zone settings. The research will be conducted by using a unique combination of experimental and theoretical methods.
