Welcome to GEOTRACES
GEOTRACES is an international programme which aims to improve the understanding of biogeochemical cycles and large-scale distribution of trace elements and their isotopes in the marine environment. Scientists from approximately 35 nations have been involved in the programme, which is designed to study all major ocean basins over the next decade.
GEOTRACES Sections. For more information please click here. In red: Planned Sections. In yellow: Completed Sections. In black: Sections completed as GEOTRACES contribution to the IPY. Download the map.
GEOTRACES Brazil Workshop - Final Statement Available!
- Published on Thursday, 28 May 2015 08:37
The Final Statement resulting from the GEOTRACES Brazil Workshop (21-22 March, 2015, Santos, Brazil) is now available on the GEOTRACES site.
Please click here to download it.
Thorium and protactinium radionuclides enlighten marine particles processes
- Published on Thursday, 28 May 2015 08:26
Thanks to the compilation of thorium 230 (230Th) and protactinium 231 (231Pa) data obtained along north-south and east-west transoceanic sections (in the Atlantic and Pacific Oceans), Hayes and co-workers (2015, see reference below) enlighten the processes at play among the lifestyles of marine particles, namely the adsorption to particles (scavenging) of these tracers. This systematic study is of first importance because both tracers are useful chronometers of particle dynamics and can be used to predict the adsorption of other insoluble trace metals in the water column. They find a widespread impact of authigenic Fe/Mn hydroxides as major scavenging phases (be it of hydrothermal or deposited sediment origin). They also show that biogenic opal is not a major scavenging phase due to the low abundance of opal in the water columnThey eventually discuss why the distribution coefficients are surprisingly low in surface water, but if you wish to know more…read it!
Figure: With samples from the U.S. North Atlantic Zonal Transects (upper map), we investigated how the radionuclides Th and Pa “stick” onto particles by analyzing their dissolved (bottom section) and particulate (middle section) phases in seawater, along with the amount and chemical composition of the particles. The ratio of Pa to Th in ocean sediments can be used as a proxy for properties of the ocean’s geologic past, but this ratio fundamentally depends on the relative intensity of each metal’s “stickiness” or tendency to adsorb onto various particles. Among many observations, we found the Pa/Th ratio was largely driven by the total amount of particles (top section) but was also significantly affected by a relatively minor mineral phase, the iron-manganese oxides forming at the Mid-Atlantic ridge and in West African margin sediments. Click here to view the image larger.
Special Issue devoted to the U.S. GEOTRACES North Atlantic Transect is published!
- Published on Friday, 22 May 2015 09:13
Everything you always wanted to know about trace elements and isotopes (TEI) distribution in the North Atlantic... but were afraid to ask
Many answers could be find in the Deep Sea Research Part II special issue dedicated to the results of the US GEOTRACES section cruise GA03: a beautiful water mass analysis settled the frame to no more than 24 other studies of a wide range of isotopes (from the hydrogen to the protactinium ones) and of the diverse distributions of many trace elements, with some focus on their role on the diazotrophic species activity... This is among the most exciting issues of this month (at least!)...don't waste time, get it, open it, read it!
|Deep Sea Research Part II: Topical Studies in Oceanography
Volume 116, Pages 1-342 (June 2015)
GEOTRACES GA-03 - The U.S. GEOTRACES North Atlantic Transect
Edited by Edward A. Boyle, Robert F. Anderson, Gregory A. Cutter, Rana Fine, William J. Jenkins and Mak Saito
Intermediate Data Product 2014 version 2 and DOI - Available!
- Published on Thursday, 21 May 2015 12:26
The corrected and updated of the GEOTRACES Intermediate Data Product 2014 (IDP2014) is now available. The new version (version 2) of the digital data is now available in four formats (ASCII, Excel, netCDF, and ODV) from www.bodc.ac.uk/geotraces/data/idp2014/.
For further details on the revisions made please click here. Please also remember to clear your cache so as to ensure the correct files can be accessed.
The IDP2014 should also be cited in the following way:
Mawji, E., et al., The GEOTRACES Intermediate Data Product 2014, Mar. Chem. (2015), http://dx.doi.org/10.1016/j.marchem.2015.04.005.
This citation text is included in the new download agreement document available here.
- Insights into Particle Cycling from Thorium and Particle Data
- Shallow methylmercury production in the marginal sea ice zone of the central Arctic Ocean
- Submarine Groundwater Discharge as a major source of nutrients in the Mediterranean Sea
- GEOTRACES Marine Particles Special Issue Published!
- Join GEOTRACES webinar series!