The Department of Earth Sciences at Utrecht University is currently seeking a motivated PhD candidate to work on the research project:
Using space geodesy and mechanical models to assess the re-locking time
a major subduction earthquake.
An interdisciplinary team involving the Tectonophysics group at Utrecht University (Govers), Geoscience and Remote Sensing at Delft Technical University (Riva), and Departement Terre Atmosphère Océan at École Normale Supérieure (Vigny) seeks a Ph.D. student to work in a collaborative programme on the mechanics of the largest earthquakes. Subduction megathrust events occur on segments of the interface that have been locked by friction for 100s to 1000s of years. Immediately after an earthquake, transient processes obscure the GPS signal from these locked zones. Historical earthquakes that repeatedly rupture the same region demonstrate that the interface re-locks eventually. More information comes from recent marine geodetic observations offshore Tohoku (Japan) which suggest that re-locking occurred within a few months after the 2011 event, but we do not know whether this behavior is also typical for other margins. The Tohoku observations only constrain to the shallowest portion of the interface, but we do not know whether deeper segments re-lock in concert with up-dip segments. We aim to isolate the re-locking from GPS observations to address these questions, which is critically important for assessing earthquake hazard. This new approach will be applied to GPS time series of benchmarks along three well-instrumented subduction margins where recent megathrust events occurred, in Tohoku (Japan), Maule (Chile), and Sumatra (Indonesia).
We will use geodynamic models to remove the contribution to the data of post-seismic processes. The project will revolve around massively parallel finite element models, built on OpenMPI and PetSc, that solve the relevant partial differential equations for the lithosphere and uppermost mantle. The aim is to make existing models more realistic and tailored to specific margins to evaluate the imprints of the earthquake cycle, geometric complexity, and alternative modes of post-seismic relaxation. The models are driven by plate tectonic velocities, involve many megathrust cycles to generate consistent pre-stresses, and incorporate semi-dynamic earthquakes, afterslip and visco-elastic relaxation in the mantle wedge.
You will be expected to publish the results in papers in top journals. You will work in the Tectonophysics team, led by Govers, which includes 3 PhD students and postdocs, and a model support technician. Up to 10% of your time will be dedicated to assisting in the BSc and MSc teaching programmes of the Department of Earth Sciences. A personalised training programme will be set up and mutually agreed upon recruitment, which will reflect your training needs and career objectives.
The project is financed through the Netherlands Space Office (NSO) and the Netherlands Organisation for Scientific Research (NWO).
You are an enthusiastic graduate student holding an MSc degree in a relevant field for the position. In particular
- You should have a relevant background in numerical geomechanics, ideally with ample experience with FEM.
- You are expected to be intimately familiar with Linux-like systems, to be fluent in at least one modern computer language (Fortran, C, C++).
- You should have the ambition to excel in this field, have a background in geophysics, and have a strong interest in subduction zone earthquakes.
- It is essential that you are willing and able to interact in a multidisciplinary team. Important accessory qualifications include positive social/verbal/communication skills, determination, willingness to travel abroad, eagerness to develop multidisciplinary skills, and ability to share and explain results to other researchers (also from other disciplines). You should have excellent written and spoken English skills.
Terms of employment:
You will be offered a full-time position at first for one year. Depending on a good performance this may be extended to a total period of four years, with the specific intent that it results in a doctorate within this period. Employment conditions are based on the Collective Labour Agreement of the Dutch Universities. The gross monthly salary starts with € 2,222,- in the first year and increases to € 2,840,- in the fourth year of employment with a full-time appointment. The salary is supplemented by a holiday allowance of 8% per year and an end-of-year bonus of 8.3%. In addition, we offer a pension scheme, collective insurance schemes and flexible employment conditions.
Facilities for sports and child care are available on our main campus (where the Department of Earth Sciences is situated), which is located only 15 minutes away from the historical city centre of Utrecht.
About the organisation:
The Utrecht Faculty of Geosciences offers education and research concerning the geosphere, biosphere, atmosphere and hydrosphere. With a population of 2600 students (BSc and MSc) and 600 staff, the Faculty is a strong and challenging organisation. The Faculty is organised in four Departments: Innovation, Environmental & Energy Sciences, Earth Sciences, Physical Geography, and Human Geography & Spatial Planning.
The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. The department hosts a highly international group of more than 100 PhD students and postdoctoral researchers and houses a wide variety of world-class laboratories.
For additional information please contact the project leader Dr Rob Govers, email@example.com.
How to apply:
To apply, please follow this link and the guidelines mentioned there. Applications will be accepted until March 15th, 2018. Evaluations and interviews are planned soon thereafter. We aim to start the project ultimately on the 1st of July, 2018. Online screening may be part of the selection. Commercial response to this ad is not appreciated.