School of Earth and Environment

Andrew Walker Dr Andrew Walker

NERC Independent Research Fellow

Telephone number: +44(0) 113 34 33803
Email address: A.Walker@leeds.ac.uk
Room: 8.141

Affiliation: Institute of Geophysics and Tectonics

Link to personal page

Biography

After completing a PhD in computational mineral physics at the Royal Institution in 2004 I took up a one-year postdoctoral fellowship at the Research School of Earth Sciences at the Australian National University where I worked on, amongst other problems, the mechanism of incorporation of water in mantle olivine. I returned to the UK at the end of 2005 to join the eMinerals consortium at the University of Cambridge. This position enabled me to begin to develop software in a serious way alongside my research activity and I still maintain some of the results of this work (see http://homepages.see.leeds.ac.uk/~earawa/software/).

In 2007, I was awarded a three-year NERC Postdoctoral Research Fellowship to investigate dislocation-mediated processes in the mantle. This project, hosted in Cambridge and UCL, allowed me to revisit a problem from my PhD and further develop methods of modelling dislocations on the atomic scale. At this time I was also able to redevelop my interests in experimental studies, something I had not focused on since my undergraduate research project. I then moved to the University of Bristol to join the ERC funded CoMITAC project focused on the core mantle boundary. My role on this project, to build models linking seismic observations with simulations of mantle flow, allowed me to tackle deformation processes at a larger scale then I had attempted previously. This equipped me to undertake multi-scale simulations of mantle rheology, and brought me to Leeds at the end of 2013 to commence a NERC Independent Research Fellowship.

Qualifications

  • PhD in Geology, University of London (2004). Thesis title: “Computational studies of point defects and dislocations in forsterite (Mg2SiO4) and some implications for the rheology of mantle olivine”, supervised by Kate Wright and Ben Slater and undertaken at the Davy Faraday Research Laboratory, The Royal Institution of Great Britain.
  • MSci in Geological Sciences, UCL (2001). Final year research project: “The effect of pressure on the thermal expansion of diopside: a computational and experimental study”, supervised by Ian Wood, Lidunka Vočadlo and David Price.

Research Interests

My research interests are in the broad field of computational geophysics and mineral physics with a particular emphasis on the simulation of the consequences of the presence of imperfections in the crystal structure of Earth materials at multiple scales. My early research involved the simulation of minerals at the atomic scale. My more recent work builds on this knowledge base and tackles larger scale geodynamical problems linking global scale mantle convection with the generation of texture and seismic anisotropy. My interests thus span scales from the atomic to the whole mantle and couple mineral physics, seismology and geodynamics.

A major part of my current research involves the multiscale simulation of how the minerals which form the mantle transition zone deform to allow the mantle to convect and drive plate tectonics. This project, which is funded by one of the first generation of NERC's new Independent Research Fellowship scheme, involves simulation of deformation from the scale of the motion of isolated imperfections in single crystals, through defect - defect interactions to the deformation of pollycrystalline rocks. A major aim of the project is to combine these models with simulations of mantle convection at the global scale in order to resolve how the complex history dependent rheology of the transition zone controls the planetary scale dynamics. This project involves a number of important collaborations and several different strands of research. Further details of this project, and of other projects that I have been involved with, can be found at http://homepages.see.leeds.ac.uk/~earawa/projects.html.

Academic CV (pdf file)

Publications