Costa Rican subduction - connecting Earth’s deep water cycle to earthquake and volcanic hazard

Dr Catherine Rychert, Dr Marino Protti
Rationale: 

Understanding the pathways of fluids is fundamental to our understanding of natural hazards, climate, and the habitability of the planet. Subduction zones are of particular importance. Here ocean plates descend into the Earth causing earthquakes and carrying hydration into the Earth. This causes melting and surface volcanism, releasing water back to the surface. Thus water, plate tectonics, and habitability are intricately linked. However, the exact pathways of the fluids and the factors that control melting dynamics leading to volcanic eruption are still not well-known. Costa Rica in particular suffers major earthquakes and volcanic eruptions regularly. Costa Rica also has a wealth of high-quality seismic data that will be used to generate a high-resolution crust and mantle velocity model to enhance hazard mitigation associated with its volcanoes and earthquakes. This project will link mantle dynamics and fluid pathways with hazard mitigation. The project will involve collaboration with Dr. Marino Protti, at The Volcanological and Seismological Observatory of Costa Rica, Universidad Nacional (OVSICORI-UNA). The project will have great societal impact as Dr. Protti is not only an expert in Costa Rican seismicity, volcanoes, and tectonics, but also engaged in science diplomacy and public policy.

Methodology: 

The student will use a rich dataset including both local and teleseismic earthquakes and the following seismic methodologies:

  1. Classic seismic methodologies will be used to image the crust, overriding plate, mantle wedge, and subduction slab including body wave, surface wave, and attenuation tomography and P-to-S and S-to-P receiver functions.
  2. Characterization of seismicity - earthquakes will be located, and focal mechanisms will be investigated to directly link with tectonics.
  3. Integration - the student will integrate the results via joint inversion and also by collaboration with petrologists, geochemists, and geodynamic modelers. Integration into the global dataset will be a possibility
  4. More advanced approaches such as machine learning and/or full waveform modelling using finite difference or spectral element methods will be used to attain the highest possible resolution and further investigate interdisciplinary aspects of the results, such as the physical and chemical implications for a range of geophysical and geochemical constraints.

 

Location: 
University of Southampton
Training: 

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at University of Southampton. 

The student will gain experience with cutting edge codes and methodologies. The student will develop skills and learn techniques from passive source seismology as a member of one of the largest and most active geophysics groups in the UK. The student will learn to cull, process, and invert seismic data using dense seismic arrays. The student will have excellent computational facilities and be trained in programming skills for Python, Seiscomp3, FORTRAN, Matlab, SAC, and the UNIX operating system. A wide range of opportunities to develop the range of generic skills essential for successful completion of the PhD and their future career are available through the Graduate School NOCS including geophysical fieldwork in Costa Rica. This training will prepare the student for a career path in academia and industry.

Eligibility & Funding Details: 

Please check https://inspire-dtp.ac.uk/how-apply for details.  

 

Background Reading: 

Rychert, C. A., K. M. Fischer, G. A. Abers, T. Plank, E. Syracuse, J. M. Protti, V. Gonzalez, and W. Strauch (2008) Strong Along-Arc Variations in Attenuation in the Nicaragua-Costa Rica Mantle Wedge, Geochem., Geophys., Geosyst., 9, Q10S10, doi:10.1029/2008GC002040.

 

Protti, M., González, V., Newman, A. et al. Nicoya earthquake rupture anticipated by geodetic measurement of the locked plate interface. Nature Geosci 7, 117–121 (2014). https://doi.org/10.1038/ngeo2038

 

Possee, D., C. A. Rychert, N. Harmon, and D. Keir (2021) Seismic Discontinuities across the North American Caribbean Plate Boundary from S-to P- Receiver Functions, Geochem., Geophys., Geosyst., doi:10.1029/2021GC009723