Seminars Archive

Probing the Earth`s core with quantum mechanics

Abstract


Wednesday, January 26, 2005, 14:00
Seminar Room, ground floor, Building "T"
Sincrotrone Trieste, Basovizza
Probing the Earth`s core with quantum mechanics


Dario Alfe`

(Dept. of Earth Sciences, and Dept. of Physics and Astronomy University College London)
Abstract
The heat coming from the Earth`s core is one of the most important sources of energy which drive all the dynamics processes inside our planet, and ultimately also surface processes like volcanism, plate tectonics and earthquakes. The main constituent of the Earth`s core is iron, therefore its elastic and thermodynamic properties at high pressure and high temperature are central in our understanding of the properties of the core. We also know that the core must contain some light impurities like S, Si, O, etc., as iron is 6-10 % too dense. As the (solid) inner core freezes, these light impurities are released in the (liquid) outer core, and rise to the surface of the core. In doing so, they stir the liquid into convective motions which are responsible for the generation of the Earth`s magnetic field. Two big questions in Earth`s sciences are therefore what is the temperature and the composition of the Earth`s core. In this talk I will focus on high pressure high temperature properties of iron and iron alloys calculated using first principles thermodynamics. In particular, I will present the melting curve of iron and constraints on the possible composition of the the Earth`s core.