Understanding of the influence of petit-spot volcanism on the structure of the lithosphere on the basis of multi-parameter, high-resolution seismic imaging of seismic data from the Japanese Trench
Date of starting recruitment: 2023-01-27
Deadline for submitting applications: 2023-02-28
Requirements:
- Master degree in geoinformatics, geophysics, physics or similar. It is allowed to submit applications by people who graduate from studies in the coming months and will submit the opinion of the master’s thesis supervisor.
- Knowledge of research topics related to the propagation of seismic waves, seismic imaging, numerical and inversion methods
- Very good programming skills in one of languages (Fortran, C++, Python, Matlab)
- Knowledge in the field of seismic data processing and interpretation
- Experience in HPC computing and clusters
- Very good English speaking and writing skills enabling the presentation of results at international conferences, communication, reading and writing scientific papers.
Tasks description:
The PhD student will join the group implementing the NCN project no. 021/43/B/ST10/00965 titled “Understanding of the influence of petit-spot volcanism on the structure of the lithosphere on the basis of multi-parameter, high-resolution seismic imaging of seismic data from the Japanese Trench”. The project is scheduled for 48 months (from 2023-03-01 to 2026-09-30).
Title of the NCN call: OPUS 22
The main tasks include:
- Application of velocity model building methods – traveltime tomography and full-waveform inversion – to the wide angle ocean-bottom seismometer data
- Source code development and application of least-square reverse time migration scheme to the reflection streamer data
- Participation in doctoral school courses
- Reporting of the results during conferences and via scientific articles
- Participation in research visits
How to apply:
To be employed, a candidate must participate in the Geoplanet Doctoral School of the Institute of Geophysics, Polish Academy of Sciences.
Required documents should be sent in electronic form in one PDF file (by e-mail) only to the address: studia.doktoranckie@igf.edu.pl
The following documents are required in the recruitment procedure:
- The motion to enroll in the Doctoral School along with the consent for processing personal data for the recruitment purposes and the declaration about familiarizing with the present Regulations. The specimen of the motion is included in the Attachment 1 to the present Regulations.
- A copy of the diploma certifying the completion of studies or a certificate confirming the completion of studies. In the case when the candidate is not in the possession of the above mentioned documents, he/she is obliged to deliver them before the start of the education in the Doctoral School. The documents are not required from the person referred to in Article 186 paragraph 2 of the Law.
- The list of grades obtained during the first-cycle (B.A., B.Sc.) and second-cycle studies (M.A., M.Sc.) or the list of grades obtained during the long-cycle Master Degree studies.
- The curriculum vitae containing the course of the existing education and employment, the list of publications, information on the involvement in scientific activity (membership in student research groups, participation in scientific conferences, internships and trainings, obtained awards and distinctions).
- A letter of motivation containing a short description of interests and scientific achievements and the justification why the candidate intends to undertake the education in the Doctoral School.
- Certificates or other documents stating the level of command of English language if the candidate is in possession of such documents.
- At least one letter of recommendation from the current research supervisor, academic teacher or research worker describing the candidate and his/her scientific activity that has been carried out by him/her so far. The letter can be sent by the candidate or directly by the person who wrote the letter. It is also possible that the candidate indicates a person who is a research worker or an academic teacher and holds the scientific degree from whom the recruitment commission may independently obtain such an opinion. In such a case the recruitment commission asks for such an opinion within the term that allows for taking it into consideration during the recruitment time. The possible ways to deliver the letter are included in the recruitment announcement.
Recruitment rules (valid for recruitment announced 1st October 2022 and on)
Conditions of employment
Project scholarship: Approximately 3,690 PLN net per month for a period of 48 months
Employment: Specified period of 48 months
Working time: full time
Additional information: The position is financed under the NCN project no. 2021/43/B/ST10/00965 titled “Understanding of the influence of petit-spot volcanism on the structure of the lithosphere on the basis of multi-parameter, high-resolution seismic imaging of seismic data from the Japanese Trench”. The project is scheduled for 48 months.
Project description: Petit-spot volcanism is recently discovered phenomenon that shed a new light on our understanding of the intraplate volcanism. Petit-spot volcanoes (or petit-spots) are small volcanoes that erupt along lithospheric fractures in response to plate flexure during subduction. Their discovery was of great significance, as it demonstrated, that tectonic processes have potential to cause intraplate volcanism Shortly after discovery of petit-spots, the debate emerged that the wide distribution of those volcanoes over relatively small area brings significant impact on the subduction system in terms of megathrust rupture nucleation and slip propagation. On the other hand, the petit-spots are just a small-scale surface evidences of the volcanic processes that take place in the deep lithosphere. Those processes are still not fully understood and have yet to be investigated. As for today, the high-resolution crustal-scale inversion and migration methods are the only robust techniques to image those variations.
The fundamental goal of this 4-years project is to couple leading-edge full-waveform based inversion and depth-migration techniques with different types of unique seismic data to retrieve the high-resolution models of subsurface in the outer-rise region of the Japan Trench – the area where the petit-spot volcanoes were discovered for the first time 15 years ago. In particular, we plan to reconstruct high-resolution P and S wave velocity models (Vp and Vs) using full-waveform inversion (FWI) of the ocean-bottom seismometer (OBS) data, as well as reflectivity image using least squares reverse-time migration (LSRTM) of the multi-channel streamer (MCS) data. On the methodological side of this proposal we firstly want to tackle the long standing problem of moving the velocity model reconstruction with FWI of OBS data beyond the acoustic approximation. In particular reconstruction Vs remains challenging both on the methodological and computing side, and therefore, establishing robust workflow for this type of FWI is now one of the technical challenges. Secondly, owing the fact that we will have access to the detailed FWI Vp model, we would like to adopt the LSRTM technique to fully exploit the potential of the academic MCS data for the purpose of reflectivity imaging. We want to obtain a detailed image of the changes in the sedimentary cover caused by petit-spot volcanism to understand how they alternate the inputs to the subduction zone and how it may affect the geodynamic system during nucleation and propagation of the megathrust earthquakes.