CDD - Geophysicist M - F H/F Ifremer

Closing date for applications : 13/11/2026

Who We Are ?

The Marine Hazards team (ALéas MArins, ALMA) of the Geo-Ocean Laboratory (UMR 6538) in Plouzané France develops measures, promotes new approaches, and conceives models that explain the causes, consequences, the recurrence, and the impact of geological hazards in the marine domain. The Marine Hazards team is comprised of international members within several institutions: Ifremer, CNRS, and University of Western Brittany (UBO). Within the Marine Hazards team, we have several large-scale research initiatives that address major scientific challenges such as characterizing tectonics and past and present seismic sources, active volcano monitoring, the installation of long-term seafloor observatories, characterizing submarine landslides, modeling sediment behavior, and even investigate the pathways of methane from how it leaves sediments and enters the hydrosphere and the atmosphere. Through these activities, we mobilize communities at the national and international levels. The candidate will be placed under the management of Stéphan KER, the Marine Hazards team leader. The scientific director will be Chastity AIKEN, seismologist in the Marine Hazards team.

What Will Your Role and Responsibilities Be?

This position is part of the CAST project, financed by the Agence Nationale de Recherche. The CAST project aims to understand the evolution of major strike-slip faults - the Septentrional-Oriente Fault and Enriquillo-Plantain Garden Fault - surrounding Haiti in the North Caribbean. The objectives are to improve our understanding of how these faults generate earthquakes and potentially tsunamis, and therefore how to better assess the seismic and tsunami risks in the region.

The Septentrional-Oriente Fault Zone (SOFZ), proposed to be the northern limit of the Gonâve microplate in the Caribbean Sea, is an active strike-slip fault. The SOFZ in northern Haiti is located offshore in a zone of thrust deformation. Since 1842, a few magnitude greater than 7 earthquakes have been recorded near the SOFZ and at least one tsunami, but the strongest magnitude earthquakes occurring in northern Haiti or the Dominican Republic are not necessarily earthquakes produced by the SOFZ. To better understand the seismic and tsunami risks, passive broadband seismological data was collected in the Windward Passage. Five broadband ocean-bottom seismometers were deployed between July 2024 and February 2025, and 4 were deployed and recovered between February 2025 and February 2026.

The candidate will address the following question in the context of historical seismicity: How is the seismicity linked to the SOFZ fault structure and how does the fault release its stress seismically (slowly or fast) ? You will use passive broadband seismological data to 1) detect and locate seismicity - earthquakes and/or tremors, 2) determine how the fault releases its stress, and 3) connect present day seismicity directly to the known fault structures to elucidate the depth of the seismogenic zone. Identifying the depth of the seismogenic zone is important because it is one of the important elements needed to characterize the seismic and tsunami risks. The results obtained in the framework of this position will complete databases for seismic hazard models in the Caribbean region.

What Will Your Main Responsibilities Be?

• Pre-treatment of passive seismological data, including noise correlation for time correction.
• Detection, location, and magnitude estimation of earthquakes and/or tremors.
• Determination of focal mechanisms, if possible.
• Integration of newly detected seismicity with known earthquake catalogs for interpretation.
• Co-author of a scientific manuscript.

The candidate will be responsible for the implementation of this task within the CAST project, the choice and adaptation of analytical methods as well as the interpretation of the results. Weekly scientific follow-ups with scientific director will take place throughout the contract term, to provide an opportunity to discuss progress, to adjuster project guidelines, and resolve difficulties encountered. This organization aims to assure a scientific exchange close and constructive while promoting autonomy for the candidate to carry out his/her/their work. More frequent exchanges could be organized during key phases of the project or as key deadlines approach.

Key Relationships

• Internal : Interactions with the Marine Hazards team, the Mixed Research Unit Geo-Ocean and with the IT department
• External : Work conducted in collaboration with partners in the CAST project.