GEOTRACES

An International study of the marine biogeochemical cycles of trace elements and their isotopes

GEOTRACES is an international marine geochemistry research program accredited by SCOR. GEOTRACES' mission is to identify the processes and quantify the flows that control the distribution of key trace elements and their isotopes in the ocean. In addition, the sensitivity of this distribution to environmental changes is being assessed.

The programme brings together 33 nations that work in coordination to achieve this mission. The genesis of the program began in the early 2000s with the introduction of new mass spectrometers and systems for the clean and improved sampling of seawater and particles. These tools have opened up very large and promising scientific exploration fields. In particular, they make it possible to investigate at a large scale and high spatial resolution the distribution and behaviour of chemical elements and isotopes that have hitherto been very difficult to measure. These measured chemical elements are listed below in the "Measured parameters" tab.

The data from the French biogeochemical campaigns that have been labelled by GEOTRACES (GEOVIDE, KEOPS2, PEACETIME, BONUS GOOD HOPE, PANDORA) are integrated into the LEFE-CYBER database.

After the drafting of the scientific plan (2006) and then the implementation plan (2009), GEOTRACES was officially launched in 2010 with a first data product from the program launched in 2014 and a second in 2017.

As of October 2018, 105 sea campaigns have already been carried out as part of GEOTRACES. In average, between 3 and 5 are carried out per year, depending on the fluctuations of the research arrangements and credits obtained by the various partners. The sea campaigns are scheduled to be completed in 2023.

The chemical elements measured as part of GEOTRACES are:

  • micronutrients, essential for the development of life such as: iron (Fe), Zinc (Zn), copper (Cu), cobalt (Co), cadmium (Cd), etc;
  • contaminants (Hg, Pb, and some of the above at high concentrations such as Zn, Cu or Cd);
  • informative tracers on the fall speed of matter, water age, origin and circulation.

Data availability strategy

The data of GEOTRACES is made available to all in an "open source" database hosted at the British Oceanographic Data Center (BODC).

Two intermediate data products (IDPs) have already been made available for the first time in 2014 and then in 2017. These data are delivered in various formats on the BODC website as well as in the form of an Atlas (see illustration).

This policy induces an important data quality control, which is regularly inter and cross calibrated.

More information

The GEOTRACES Program brings together 33 nations that work in coordination, each of which is responsible for organizing one or more sea campaigns. The committees that operate this program can be contacted via the following links:

  • The International Project Office (IPO) coordinates the programme's activities from the Midi-Pyrénées Observatory in Toulouse. It is led and directed by Elena Masferrer Dodas and supervised by Catherine Jeandel. Contact: ipo(at)geotraces.org
  • The Scientific Steering Committee (SSC), 23 members, representatives of the member countries. Currently the co-chairs of the SSC are Prof. Phoebe Lam (USC, California, USA) and Andrew Bowie (UTAS, Hobart, Australia).
  • The Standards et Intercalibration Committee, which ensures data quality and is co-chaired by Maeve Lohan (NOC, Southampton, UK) and Walter Geibert (AWI, Germany).
  • The Data Management Committee, which oversees their banking, with interaction with the GEOTRACES Data Assembly Centre (Mohamed Adjou, BODC, Liverpool), co-chaired by A. Tagliabue (Liverpool, UK) and W. Landing (Florida USA).
  • The Parameter Definition Committee is responsible for defining the names of parameters that correspond to a very precise architecture, co-chaired by C. Jeandel (CNRS, Toulouse, Fr) and B. Anderson (LDEO, Columbia Univ., USA).