During my undergraduate degree in Geophysics, I was able to study a wide range of topics from pore-scale fluid flow to impact cratering. Of all these, the topic that interested me most was learning about the large scale structures processes inside the deep Earth. Being so enigmatic and unknown, I was driven to find out more about the area. Using seismology is the major way we observe structures inside the Earth and aids other fields by providing these observations, fortunately, I was able to do my master's project in the field I found so interesting by analysing the Earth's inner core using waves generated by earthquakes (Title: P′P′ Analysis of Anisotropy in the Earth's Inner Core). I thoroughly enjoyed my master's project. Because of this, I searched for PhDs in a similar field and after much time and effort was offered a PhD scholarship at Leeds. I am part of the Leeds-York NERC Doctoral Training Partnership (DTP), 2017 cohort and am currently the geosphere student representative. Whenever possible, I am involved in some type of science outreach including Pint of Science, the after-school science club and PubHD.
Ward, J. Nowacki, A. Rost, S. 'Sharp Velocity Gradients in the Earth's Lowermost Mantle Resolved by Wavefield Effects of Multipathing'. Poster Presentation at the Study of the Earth's Deep Interior (SEDI) Meeting, Edmonton, Canada, July 2018.
Day, E. A., J. A. Ward, I. D. Bastow, and J. C. E. Irving. 'Inner Core Imaging Using P'P'.' In AGU Fall Meeting Abstracts. 2016.
Day, Elizabeth, James Ward, Ian Bastow, and Jessica Irving. 'Probing the inner core's African hemisphere boundary with P'P'.' In EGU General Assembly Conference Abstracts, vol. 19, p. 13175. 2017.
My project is developing and implementing a new seismic technique to quantify the level of refraction of the ray path and identify multipathing to constrain the location and properties of sharp velocity boundaries in the Earth's mantle.
Deep within the interior of the Earth exist two continent-sized structures distinct to the rest of the Earth. As these structures are located at the boundary where the liquid iron core meets the rocky Earth, they affect the Earth in several ways including surface uplift and hotspot volcanism. Currently, our observations and understanding of the structures are poor, therefore we cannot confidently constrain the effect it has on the rest of the Earth, their origins or the role they played in the evolution of the Earth. Observations of the structures from global velocity models have revealed broad properties such as their location, morphology and approximate velocity reduction relative to the surrounding mantle, but cannot resolve the finer details. Regional studies have made more detailed observations about the velocity reduction, angle and sharpness of the boundaries using travel time residuals and a phenomenon known as multipathing.
Multipathing occurs where the ray path is incident on strong lateral velocity variations over small distances, leading to multiple arrivals when only one is expected. Most previous regional structure studies using multipathing analyse the waveforms only and do not attempt to recover the full vector of the arriving wave, which gives information about the direction and inclination of the arrival. Waves travelling through the structure are expected to arrive with a different inclination and direction relative to waves travelling outside the structure.
In order for us to constrain the hypotheses for the properties and origins of the structures, new observations need to be made. My project aims to develop a new method using the full vector to determine the direction and inclination of the arriving wavefront to quantify the level of refraction around sharp velocity boundaries and identify multipathing. Using this technique I aim to resolve the location and properties of these structures and other sharp boundaries in the mantle.
- MSci in Geophysics ( 1st class Honours), Imperial College, London
Research groups and institutes
- Deep Earth
- Planetary Exploration
- Institute of Geophysics and Tectonics