skip to content

Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 
Iceland project

Lead Supervisor: Nick Rawlinson, Earth Sciences

Co-Supervisor: Sergei Lebedev, Earth Sciences

Brief summary: 
The goal of this project is to use advanced seismic imaging methods to develop a multi-scale seismic model of the crust-mantle system beneath Iceland, which has important implications for understanding its structure and how it has evolved over time.
Importance of the area of research concerned: 
Iceland straddles the boundary between the North American and Eurasian plates in the North Atlantic, and has formed as a consequence of the interaction between a deep sourced mantle plume and the mid-Atlantic ridge. This has given rise to two forms of decompression melting; one caused by the rising plume, and the author caused by plate spreading. This increased melting has produced a crust some 4-5 times thicker than normal oceanic crust, and when combined with dynamic uplift caused by the plume, has lead to the generation of a large new land mass which is characterised by extensive volcanic zones. This unique tectonic setting provides a natural laboratory for investigating key questions regarding crustal growth, melt generation in the mantle, the role of plumes in the growth of new crust, and how mid-ocean ridges can accommodate atypical crustal formation. Thanks to the long term deployment of broadband seismic stations throughout Iceland, passive seismic imaging methods are ideally placed to help illuminate deep features in the crust and mantle beneath that are crucial for understanding these fundamental tectonic and volcanic processes.
Project summary : 
The aim of the project is to combine multiple classes of seismic data, including local earthquake, regional and teleseismic traveltimes, receiver functions and surface wave dispersion extracted from ambient noise and earthquakes, to jointly constrain the 3-D seismic structure of Iceland’s crust and upper mantle. Various software packages, including FMTOMO, could be used to achieve this goal, although it is likely that the student will want to further develop some of these codes for their own analysis. The option also exists to investigate whether adjoint waveform tomography might be usefully applied in this context, since it can naturally incorporate both body and surface wave arrivals. An extensive waveform dataset that extends back nearly two decades will be available for this project.
What will the student do?: 
The student will join an experienced fieldwork team in servicing our broad-band seismometer array in central Iceland, and help integrate new data with our existing catalogue of seismic data in the region. They will then assemble and groom a high quality dataset comprising various seismic data types, and then apply advanced inversion methods to image the 3-D seismic structure of the Icelandic crust and upper mantle. This project would best suit a student with solid computational skills, and a willingness to modify existing software to optimise the extraction of structural information from the combined dataset. They would also be expected to interpret their results taking into account previous seismic imaging work, and complementary results from other Earth Sciences disciplines (e.g. geodesy, petrology, geochemistry, structural geology, volcanology). Extensive expertise in Iceland tectonics and volcanology currently exists in the department, which the student can harness to their benefit.
References - references should provide further reading about the project: 
Volk, O., White, R. S., Pilia, S., Green, R. G., Maclennan, J. & Rawlinson, N. (2021). Oceanic crustal flow in Iceland observed using seismic anisotropy, Nature Geosciences, vol 14, 168-173.
Rawlinson, N. & Urvoy, M. (2006). Simultaneous inversion of active and passive source datasets for 3-D seismic structure with application to Tasmania, Geophysical Research Letters, L24313.
White, R. S., Edmonds, M., Maclennan, J., Greenfield, T. and Ágústsdóttir, T. (2018). Melt movement through the Icelandic crust. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol 377, 1471-2962
Applying
You can find out about applying for this project on the Department of Earth Sciences page.
Sergei Lebedev
Prof Nicholas Rawlinson
Department of Earth Sciences Graduate Administrator