The
Department of Earth Sciences is looking for a highly motivated postdoctoral researcher (up to four years) and PhD candidate (four years) to model and image the earthquake system in subduction zones.
Your job You will be part of a multi-disciplinary team largely funded by a 2.5-million-euro ERC Consolidator grant "RESET: mega-thRust Earthquake System Theory" awarded to
Dr Ylona van Dinther.
RESET aims to drastically improve inferences of future earthquake locations, sizes, and maybe even timing. Significant advances will come from integrating more satellite observations and novel system-based physics. RESET will introduce an Earthquake System concept and model, which unifies motions across the subduction interface, tectonic plates, and mantle bridging space, time and methodological inference scales. This will allow us to infer fault motions and system processes from surface velocities observed with satellites. Currently, that is done by inverting horizontal velocities either before, during, or after earthquakes. Together we will add the inversion of vertical velocities, and assimilate observations before, during and after earthquakes.
Methodologies build forth on our groups advances, which also predicted the newly observed vertical velocities. To integrate unprecedented amounts of data in a visco-elasto-plastic Earth-like system we will leverage the latest High-Performance-Computing research for forward and inverse modelling on Graphical Processing Units (GPU’s). Your multi-disciplinary efforts will be critical, because estimates based on new vertical velocities suggest current depth estimates for future earthquakes could be significantly off. This could make the difference between anticipated shock and world-class disaster for up to 3 billion people living close to subduction zones and coastlines. Moreover, your work will contribute to developing a community code that will allow many to unlock discoveries through applications to more processes, observations, and regions.
Currently, we seek one PhD candidate and one postdoctoral researcher. The focus and extend of each position will be tailored to your expertise’s and interests, as we intend to build a strong team based on the best candidates. Hence, we encourage candidates from a wide range of backgrounds to apply. There are two main focus areas and the decision to appoint either the PhD or the postdoc to each position, will be made based on the potential candidates. Therefore, in your application, we welcome you to express and motivate your specific interests and preferences.
One position focuses on forward modelling of earthquake sequences in self-consistent lithosphere-mantle-subduction fault systems. You will develop massively parallel 2D and 3D Earthquake System models based on pseudo-transient solvers running on GPU’s. These High-Performance-Computing methods are being developed within
GPU4GEO using
Julia for applications ranging from geodynamics to glaciology. You will develop the earthquake modelling branch by implementing our invariant rate-and-state friction formulation and developing a setup for subduction zones. You will run both cross-scale and observationally constrained regional simulations with unmatched realism in geometry and rheology. You will focus on simulating Chilean, Japanese, and Cascadian margins to understand how which fault slip, plate tectonic and mantle processes govern vertical velocities before, during, and after earthquakes as well as other geodetic observations. You will build the foundations to integrate these multi-scale processes into a dynamic concept of plate tectonics.
The second position will focus on inverse modelling in form of Bayesian inference. In this position you will develop massively parallel, adjoint-based inverse methods to infer fault motions and material parameters adopting Earthquake System consistency. You will retrieve the adjoint gradients for a visco-elasto-plastic rheology through leveraging GPU4GEO’s automatic differentiation tools. In synthetic tests you will develop, verify and optimize novel inversion procedures to exploit their multi-parameter and multi-observational potential. You will apply these methods to invert horizontal and vertical surface velocities measured by satellites before, during and/or after earthquakes. This will allow you to infer fault motions that e.g., indicate future earthquake locations. A non-linear inversion will also allow you to infer viscous, elastic and potentially brittle/plastic parameters. You will study the subduction zones in Japan, Chile, North-Western United States and the Caribbean Antilles.
Both positions will be hosted in the
Earth Simulation Laboratory, one of the largest experimental laboratories to study the physical behaviour of the Earth. From under
Ylona van Dinther's lead, you will interact with colleagues with different expertises, including Seismology, Experimental Rock Deformation (
André Niemeijer), Tectonophysics, and Mantle Dynamics. You will work as part of the GPU4GEO community with e.g.,
Ludovic Räss (Lausanne, ETH Zürich) and
Boris Kaus (Mainz), and in close collaboration with our permanent Earth Science Numerical Support team.
As a post-doctoral researcher, you may be given the opportunity to contribute to the supervision of PhD candidates and BSc/MSc student graduation projects, in line with your research area. This post-doctoral position is intended to last for four years and extension to this full period will be evaluated after one year.
As a PhD candidate, you will become an independent scientist with a doctoral degree in four years. We will set up a personalised PhD training programme, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes following courses/workshops as well as training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University.
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