Project Description:

A fundamental requirement of modelling Earth’s core is that results from computer simulations and experimental studies of material properties should match the available seismic data. The observed shear wave velocity has always been significantly lower than that determined for iron from simulations or experiment.

In a recent study, however, Martorell et al. (2013) have shown that iron exhibits weakening just before melting resulting in a consequent reduction in elastic properties, including wave velocity; this provides a compelling explanation for previous differences between the observations and the experimental and theoretical results.

If we are to understand the dynamics and evolution of the Earth, we must be able to determine accurately the properties of core phases under pre-melting conditions. The question this PhD proposal wishes to address is this: is pre-melting behaviour, which dramatically alters physical properties, prevalent across all core-forming materials?

Policy Impact of Research:

If the pre-melting behaviour turns out to be “true”, all core dynamics and evolution models will have to be re-evaluated.