GEOMAR Helmholtz Centre for Ocean Research Kiel is a foundation of public law jointly financed by the Federal Republic of Germany (90 %) and the state of Schleswig-Holstein (10 %) and is one of the internationally leading institutions in the field of marine sciences. Currently GEOMAR has an annual budget of approx. 80 million Euro and has approx. 1000 employees.

The research unit "Paleo-Oceanography" of research division "Ocean Circulation and Climate Dynamics" is offering the position of a

Postdoctoral Researcher (m/f/d): Radiogenic and stable isotope geochemistry in the Equatorial Pacific Ocean as part of the International GEOTRACES Programme

Available from April 1st 2023

Job Description

A research cruise with FS Sonne (SO298) is scheduled for April-May 2023 in the equatorial Pacific Ocean from Guayaquil (Equador) to Townsville (Australia), with a focus on trace metal biogeochemistry and chemical oceanography but also including physical and biological oceanographic components. The research topic of the cruise is to determine in detail the distributions, sources and sinks of trace elements and their isotopes (TEIs) in the water column along a zonal section across the equatorial Pacific. The successful candidate will investigate the factors controlling the distribution of Nd isotopes and REEs, as well as of stable Si and Ba isotopes. The supply pathways of these TEIs to the Equatorial Pacific from the ocean boundaries (South America and the Western Pacific Island Arcs, Australian dust) and the ocean crust (hydrothermalism), as well as their cycling related to surface ocean bioproductivity will be subject of the project. The TEI distribution will be compared to the near surface currents and the deep circulation of the equatorial Pacific in order to better constrain their suitability as water mass tracers in the present and past ocean. The cruise will officially be part of the international GEOTRACES program.

Job Description / Duties

The successful candidate will be part of an international GEOTRACES team that will investigate trace metal biogeochemistry in the equatorial Pacific Ocean and its links to ocean productivity. The candidate will be working closely with physical and chemical oceanographers during the SO298 cruise program and will undertake sampling and filtration for Nd, Si and Ba isotope measurements as well as REE analyses and will perform coprecipitation at sea for Nd isotope analysis. The candidate will analyse the samples in the home laboratory at GEOMAR and establish the distribution of these elements and isotopes in the equatorial Pacific Ocean in relation to bioproductivity, input sources, and water mass mixing, and will (in the case of Si isotopes) assess the silicate utilisation by diatoms in the euphotic zone. The tasks of the candidate will comprise the scientific interpretation of the data, their presentation on national and international scientific meetings and the publication of the results in established peer-reviewed scientific journals. The candidate will communicate routinely with other members of the International GEOTRACES programme and will contribute to the management of the equatorial Pacific GEOTRACES project


  • A PhD in chemical oceanography or similar field is required or will have to be achieved by March, 31st 2023.
  • Experience in the determination of isotopic compositions of oceanic waters or sediments using MC-ICPMS is required.
  • Experience in clean sampling of ocean waters for trace metal analysis is required.
  • We expect excellent English language skills and willingness and experience to participate in sea-going expeditions

The position is subject to a final funding approval by the BMBF. This is a full-time position according to 100% of a full-time equivalent. The position cannot be split. Flexible work time models are possible.

The position is available for a funding period of 26 months. The salary depends on qualification and could be up to the class 13 TVöD-Bund of the German tariff for public employees.

GEOMAR Helmholtz Centre for Ocean Research Kiel seeks to increase the proportion of female scientists and explicitly encourages qualified female academics to apply.

GEOMAR is an equal opportunity employer and encourages scientists with disabilities to apply. Qualified disabled applicants will receive preference in the application process.

Applications including a letter of motivation, CV and contact details of 3 referees should be sent to the following e-mail ( ) in a single pdf file, using the keyword "Frank - GEOTRACES Equatorial Pacific".

Please send your application not later than November 15th 2022.

As soon as the selection procedure will be finished, all your application data will be removed according to data protection regulation.

For further information regarding the position and research unit please contact Prof. Dr. Martin Frank (

Please do not contact us by phone about the present state of procedures. However, we will answer all your questions if you send us an e-mail to In doing so, please refer to the above keyword.

GEOMAR is a member of the Helmholtz Association and the German Marine Research Consortium (KDM). For further information please visit or

GEOMAR is committed to a non-discriminatory personnel selection. Our job advertisements address all people.

The TOTAL E-QUALITY award is presented to GEOMAR for efforts in terms of human resource management aimed at providing equal opportunity.

published: 12 October 2022     Please mention EARTHWORKS when responding to this advertisement.