The Department of Earth Sciences at Utrecht University is currently seeking a motivated PhD candidate to work on the research project Fingerprinting vertical land motion from the earthquake cycle above subduction zones.

An interdisciplinary team involving Rob Govers (Tectonophysics group at Utrecht University), Femke Vossepoel (Geophysical Data Assimilation) and Riccardo Riva (Sea Level and Geophysics) from Technical University Delft seeks a PhD student to work in a collaborative programme on the mechanics of the largest earthquakes.

Large subduction earthquakes can induce meter-scale vertical land displacements along seashore regions that can be 100s of kilometres long. The displacements are spatially highly variable in both sign (up or down) and magnitude. Recent observations demonstrate that the displacements evolve rapidly during the early post-seismic period. Vertical land motions continue during other stages of the earthquake cycle. These continual relative sea level changes can be very impactful for coastal communities.

We will use data assimilation for combined updates of steady parameters and states of 3D mechanical finite element models. This innovative approach is designed to overcome the major limitations of recent studies.

We will use 3-component GNSS time series, tide gauge data corrected with data from satellite altimetry, leveling data, and available geological data to constrain the (relative importance of the) earth processes that cause vertical motions of the land surface and ocean floor during various stages of the megathrust earthquake cycle.

We investigate two subduction margins where very large earthquakes happened since the GNSS network came online, and where the network density is high (Tohoku and Maule).
We constrain the information content of the observations regarding earthquake cycle processes.

We will test our hypothesis that these processes are the same at different subduction margins and that observational differences are driven by differences in margin geometry.

We will assimilate uplift/subsidence data for the post-seismic period of the 1964 Alaska earthquake, where modern GNSS time series came online ~4 decades after the event.

Question will be to what extent the data assimilation tightens the constraints on parameters and model states in a context where we (may have to) assume that the processes are very similar to other margins. If successful, our new approach can be applied to forecast sea level changes due to the megathrust earthquake cycle.

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 for the entire 4-year PhD period by 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 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.

You will be offered a full-time PhD position (1.0 FTE), initially for one year with extension to four years in total upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period. The gross salary starts with €2,395 per month in the first year and increases to €3,061 per month in the fourth year of employment (scale P according to the Collective Employment Agreement of the Dutch Universities) for a full-time employment. Salaries are supplemented with a holiday bonus of 8% and a year-end bonus of 8.3% per year. In addition, Utrecht University offers excellent secondary conditions, including an attractive retirement scheme, (partly paid) parental leave and flexible employment conditions (multiple choice model). More information about working at Utrecht University can be found here.

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