PhD Project: Probing the water content of Earth's mantle - hydrogen mobility under extreme conditions
Research over the past few decades has shown that most of the nominally anhydrous minerals (NAMs) of Earth’s mantle can incorporate substantial amounts of water as structurally bound hydrogen. This has important implications for understanding the geochemical and geophysical properties of Earth’s interior as the presence of water influences numerous mantle properties and processes including rheology, viscosity and melting behaviour. Water, as hydrogen, has been invoked to reconcile differences between conductivity models and geophysical observations of the mantle, but no consensus has been reached regarding the exact amount – with experimental estimates differing by several orders of magnitude.
The aim of my project is to use novel hydrogen-deuterium exchange experiments, performed under mantle conditions, to provide data on hydrogen mobility on mantle minerals that will be used to determine the influence of hydrogen on conductivity. Results will be used in conjunction with existing estimates of conductivity and Magnetotelluric survey data to better constrain the water content of the mantle.