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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Nick Rawlinson, Earth Sciences

Co-Supervisor: Bob White, Earth Sciences

Brief summary: 
The goal of this project is to combine advanced earthquake detection and location techniques together with methods designed to detect small-scale changes in seismic structure in order to track melt migration and storage beneath the Reykjanes Peninsual in Iceland.
Importance of the area of research concerned: 
Since late 2019, the Reykjanes Peninsula in southwest Iceland has been in a state of unrest, as testified by elevated levels of seismicity and evidence of surface uplift from InSAR. From early 2020, this escalated into a “seismic crisis” featuring thousands of earthquakes per day, culminating on the 19th March 2021 in a dyke intrusion and eruption near Fagradalsfjall in the southwest region of the peninsula. This is the first volcanic eruption to take place in the Reykjanes Peninsula for ~800 years, and while currently low volume, the historical record of volcanism in this area suggests that the present event may be a precursor to further seismicity and eruptive activity, with possible impacts on infrastructure and habitation. The dense distribution of seismic stations in this region provides a unique opportunity to track melt migration from the upper mantle, and better understand how melt is stored and distributed in the crust.
Project summary : 
The aim of the project is to apply microseismic hypocentre mapping to track melt movement through the crust using our newly acquired and dense dataset from the Reykjanes Peninsula. We were fortunate to continuously operate an array from early-mid 2020, which ended up being centred on the dike intrusion and subsequent eruption. Preliminary analysis shows that we detected many 10’s of thousands of earthquakes along with ongoing tremor associated with magma migration. In this project, the student will use absolute and relative relocation techniques to accurately constrain the distribution of seismicity in time and space, and apply targeted imaging methods that focus on localised perturbations in Vp/Vs, which may be a signature of melt intrusion. The results of this study will provide the framework for an improved understanding of melt migration and storage in the crust.
What will the student do?: 
The student will join an experienced fieldwork team in servicing our broad-band seismometer array on the Reykjanes Peninsula, 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 that can be used for microseismic detection and imaging. The Quakemigrate package developed at Cambridge will be the primary detection tool and seismic imaging packages such as FMTOMO can be applied to retrieve information on perturbations in velocity structure, including Vp/Vs. This project would best suit a student with solid computational skills, and a willingness to modify pre-existing code as needed. They will also interact with other students and staff at the Department who are also studying this region using other methods such as geobarometry to measure the ascent of melt through the crust.
References - references should provide further reading about the project: 
Ágústsdóttir, T., Winder, T., Woods, J., White, R. S., Greenfield, T. & Brandsdóttir, B. (2019). Caldera collapse and dike-induced faulting recorded by intense microseismicity during the 2014-15 Bárðarbunga-Holuhraun rifting event, central Iceland, Journal of Geophysical Research, Solid Earth, 124, 8331–8357, JGRB53519, doi: 10.1029/2018JB016010
White, R. S., Edmonds, M., Maclennan, J., Greenfield, T. & Ágústsdóttir, T. (2018). Melt movement through the Icelandic crust, Proceedings of the Royal Society, Series A, 377, 20180010, doi: 10.1098/rsta.2018.0010
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.
Applying
You can find out about applying for this project on the Department of Earth Sciences page.
Prof Nicholas Rawlinson
Department of Earth Sciences Graduate Administrator