Research Associate – 4D Rock Physics
Catastrophic failure of rocks in the brittle Earth is a critically-important driving mechanism for phenomena such as landslides, volcanic eruptions and earthquakes, including induced seismicity. Failure of engineering materials can lead to large-scale infrastructure collapse and destabilisation of the subsurface. So system-sized material failure is vitally important to understand and forecast, particularly for the management of risk associated with it.
I am a postdoctoral researcher interested in the micro-mechanics of faulting, the statistical physics of fracture phenomena, damage localisation in materials under stress, controls on and the predictability of material failure, earthquake source physics, and relating inferences made about the subsurface from acoustic monitoring with local changes in micro-structure and strain. I am also interested in the electric signals emitted during rock fracture and their potential as earthquake precursors, as well as in fluid-rock interactions and fluid flow involving fractures in the subsurface. My current role is Researcher Co-I on the NERC-funded project CATFAIL: ‘Catastrophic Failure: what controls precursory damage localisation in rocks?’ (https://gtr.ukri.org/projects?ref=NE%2FR001693%2F1), in which I conduct laboratory experiments focusing particularly on high-resolution, time-resolved (4D) in-situ imaging of rock deformation and failure using synchrotron x-ray micro-tomography. I combine the tomographic imaging with seismology and statistical physics approaches to better understand the process of catastrophic material failure. Key unanswered questions include: (i) how do cracks, pores and grain boundaries interact locally with the applied stress field to cause catastrophic failure to occur at a specific place, orientation and time?, (ii) what dictates the relative importance of quasi-static and dynamic processes?, and (iii) why can we detect precursors to catastrophic failure only in some cases?
Previous projects at University of Edinburgh include (i) a short GCRF pilot project ‘Research for Emergency Aftershock Response’ (REAR) aiming to improve understanding and operational forecasting of aftershock sequences in order to assist emergency response by determining the potential of mobile phone accelerometers to augment seismometer networks, and (ii) an industry-funded ICCR (https://iccr.org.uk/) project ‘4D Carbonate Rock Physics’ (4DRP) investigating the properties and behaviour of carbonate rocks under stress using rock deformation experiments and x-ray micro-tomography. I am also involved in developing the capability of our x-ray transparent rock deformation apparatus and the larger apparatus in the Rock Physics Laboratory at the University of Edinburgh School of GeoSciences, particularly the acoustic monitoring system.
Areas of expertise: experimental rock deformation, rock physics, earthquakes, seismology, statistical physics, in-situ synchrotron x-ray microtomography, geohazards, geophysics.