PhD Position Observability and Identifiability for Data Assimilation of Induced Seismicity in Groningen

Would you like to join an interdisciplinary team that combines systems and control theory and geomechanics to understand what drives earthquake processes?

The research programme DeepNL aims to improve the fundamental understanding of the dynamics of the deep subsurface under the influence of human interventions and the resulting effects at the Earth's surface. DeepNL focuses on induced earthquakes and subsidence caused by gas extraction in the Groningen area.

The DeepNL project NEPTUNUS (“Novel methods for the Evaluation and Physical understanding of the Transient natUre of iNdUced Seismicity”) includes three concurrent PhD projects. The PhD project advertised here concerns Observability and identifiability for data assimilation of induced seismicity in Groningen. The other two PhD projects are: "Multi-scale modelling and assessing Induced Seismicity due to Geothermal Energy Production" and "Understanding the nonstationary nature of human-induced earthquakes and its impact on geothermal energy production".

Induced seismicity, or earthquake activity caused by humans, can be studied with mathematical models. By combining these models with observations, we can better estimate and understand the underlying processes of these earthquakes. This PhD project aims at unraveling to what extent data assimilation methods such as ensemble Kalman filtering can be applied to improve our understanding of induced seismicity. As a case study, we will use available observations of ground motion at the Groningen gas field.

In a simulation environment, data assimilation has already been shown to be effective in estimating the state and parameters of seismic cycle models. However, the assimilation of actual Groningen data into models of induced seismicity is not straightforward because certain quantities can only be measured indirectly, and measurements are scarce. To successfully apply data assimilation methods, it is crucial to understand the observability (i.e., the extent to which observations inform us of the state of the subsurface) and the identifiability (i.e., the extent to which we can infer the parameters of the system from observations) of the induced seismicity process. We will model the process by a system of nonlinear differential equations and will apply methods from systems and control theory to get insight into the observability and identifiability properties of the model.

Ultimately, the outcomes of the PhD project are expected to shed light on the requirements for safe operations in the subsurface and the potential role of operational controls in the transient nature of induced seismicity. Combined with the outcomes of the other PhD projects in NEPTUNUS, findings based on models and observations of gas extraction in Groningen can be used to guide monitoring activities for the safe operation of geothermal energy production.

The PhD research will be carried out at both TU Delft and University of Groningen. You will be expected to spend 50% of your time at each university. The project will be supervised by Dr.ir. Femke Vossepoel (TU Delft) and Dr.ir. Henk van Waarde (University of Groningen). The NEPTUNUS research team is highly interdisciplinary and also includes Prof. Jan Dirk Jansen (TU Delft), Prof. Jan-Diederik van Wees (Utrecht University/TNO), Dr. Ylona van Dinther (Utrecht University), Dr. Loes Buijze (TNO) and Dr. Annemarie Muntendam-Bos (TU Delft/SodM).

A personalised training programme will be set up, mutually agreed on recruitment, which will reflect the candidate's training needs and career objectives. Up to 10% of the candidate’s time may be dedicated to teaching at the BSc and MSc programmes in Groningen and Delft.

The successful candidate should have:

• A MSc degree in Systems and Control or Applied Mathematics, and an interest in modelling geomechanical processes, or
• A MSc degree in Geosciences or (Geo)Physics and an interest in applying methods from systems and control.
• Programming experience in, for example, Python is an advantage.
• An interest in geosciences, and the willingness and capacity to interact in a multidisciplinary team, are essential.

We expect the candidate to be able to work independently and take initiative.

Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the Graduate Schools Admission Requirements .

Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1,5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2,5 years assuming everything goes well and performance requirements are met.

Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from € 2770 per month in the first year to € 3539 in the fourth year. As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills.

The TU Delft offers a customisable compensation package, discounts on health insurance, and a monthly work costs contribution. Flexible work schedules can be arranged.

For international applicants, TU Delft has the Coming to Delft Service . This service provides information for new international employees to help you prepare the relocation and to settle in the Netherlands. The Coming to Delft Service offers a Dual Career Programme for partners and they organise events to expand your (social) network.

The research will be carried out both at TU Delft and at Groningen University. In Groningen,you will work with the Systems, Control and Optimization group. This research group is part of the Bernoulli Institute for Mathematics, Computer Science and Art. In Delft, you will work with the Department of Geoscience and Engineering of the Faculty of Civil Engineering and Geosciences. You will be expected to spend 50% of your time at each university. Costs for travel between the two universities will be covered by the project.

Delft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context.

At TU Delft we embrace diversity as one of our core values and we actively engage to be a university where you feel at home and can flourish. We value different perspectives and qualities. We believe this makes our work more innovative, the TU Delft community more vibrant and the world more just. Together, we imagine, invent and create solutions using technology to have a positive impact on a global scale. That is why we invite you to apply. Your application will receive fair consideration.

Challenge. Change. Impact!

The Faculty of Civil Engineering & Geosciences (CEG) is committed to outstanding international research and education in the field of civil engineering, applied earth sciences, traffic and transport, water technology, and delta technology. Our research feeds into our educational programmes and covers societal challenges such as climate change, energy transition, resource availability, urbanisation and clean water. Our research projects are conducted in close cooperation with a wide range of research institutions. CEG is convinced of the importance of open science and supports its scientists in integrating open science in their research practice. The Faculty of CEG comprises 28 research groups in the following seven departments: Materials Mechanics Management & Design, Engineering Structures, Geoscience and Engineering, Geoscience and Remote Sensing, Transport &; Planning, Hydraulic Engineering and Water Management.

Click here to go to the website of the Faculty of Civil Engineering & Geosciences.

For more information about this position, please contact: Dr.ir. Femke Vossepoel ([email protected] ) or Dr.ir. Henk van Waarde ([email protected] ).

Would you like to join this project, but your interest and expertise lie more in geophysics than in mathematics? Please also check the other PhD positions at Delft University of Technology and at Utrecht University.

We are acutely aware that we are a diverse society and not every talented student will have had the same opportunities to advance their careers. We therefore pledge to fully account for any particular circumstances that the applicants disclose (e.g. parental leave, caring duties, part-time jobs to support studies, disabilities etc.) to ensure an inclusive and fair recruitment process that does not rely purely on common research metrics.

We are looking forward to receiving your:

• CV.
• Motivation statement.
• Degree certificates/transcripts.
• Contact details for two referees.

Shortlisted candidates will be invited to at least one formal interview, to be held in person or online. Applications are accepted until the position is filled, but we prefer to receive your application before April 1st, 2024. Evaluations and interviews are planned in April. The expected starting date is around June 1st, 2024.

Please note:

• You can apply online. We will not process applications sent by email and/or post.
• A pre-Employment screening can be part of the selection procedure.
• Please do not contact us for unsolicited services.