Grant: Discovery Grants Program - Individual

Large scale processes of heat and mass movement deep in the interior of planets control much of what happens on the surface. The focus of Dr. Secco's research program is to bring the inaccessible deep interior of planets into the lab by measuring physical properties of core and mantle materials under simultaneous extreme pressure (0-23GPa) and temperature (220-2300K) conditions in four large volume presses one of which is the largest capacity research press in North America. Novel techniques have been developed and will be employed at high pressures to measure electrical conductivity of terrestrial planetary core mimetic Fe-S-Si solids and liquids at high temperatures as well as NH3-H2O fluids at the low temperatures of subsurface oceans of outer planetary satellites. These studies will provide critical data to address the new controversies in models of thermal convection in fluid outer cores, inner core age, geodynamo, and magnetic induction in subsurface oceans of icy satellites. Using a technique recently developed in our lab, the enigmatic origin of deep focus earthquakes will be investigated by measuring acoustic emission in phase transforming mantle olivines (Mg1-xFex)2SiO4 (0.1<x<0.8) at high pressures and temperatures. These studies aim to provide an answer for the first time to the question of whether earthquakes at 350-660km depth are caused by release of seismic energy during high pressure-temperature mineral phase transformation in the olivine wedge of subducting slabs.*Answers to these questions will be woven into the fabric of the long term goals of Dr. Secco's research program. Those goals are to improve understanding of the macro-scale engines of planetary interior heat and mass flow processes by studying the micro-scale behaviour of planetary materials at interior pressure and temperature conditions. Thirteen HQP will receive extensive training in experimental high pressure-temperature mineral physics that will provide transferrable skills to prepare them for employment in academic, government and private sectors.*