231Pa and 230Th in the Arctic Ocean 1991-2015: Changes in the Eurasian and Makarov Basins

ole.valk [ at ] awi.de


230Th and 231Pa are produced in sea water by radioactive decay of Uranium isotopes (234U, 235U). Both are particle reactive and are scavenged onto settling particles. As 230Th is more particle reactive than 231Pa, their distribution in the water column and activity ratio give information about particle fluxes and circulation patterns and –intensities. Both particle fluxes and deep water circulation may respond to climatic changes in the Arctic Ocean. This study discusses temporal changes in radionuclide concentration in the context of climate change. We compare results from 1991 [1] 2007 and 2015. We present results of dissolved 231Pa and 230Th activities of samples collected in the Nansen-, Amundsenand Makarov Basins during GEOTRACES sections GIPY11 (2007, 4 stations), GN04 (2015, 10 stations) aboard RV Polarstern. Our discussion of factors controlling the 230Th and 231Pa distribution is supported by, dissolved CFC, dissolved iron and particulate 230Th and 231Pa (3 stations) collected during GEOTRACES section GN04. We find that distributions and concentrations of dissolved 231Pa and 230Th in the central Arctic Ocean have changed significantly since 1991. Dissolved 231Pa concentrations in the Makarov basin decreased by half within less than 20 years. These changes are discussed in the context of environmental changes, such as declining sea ice cover and related increase of particle fluxes or changing deep water circulation. [1] Scholten, J. C., et al. (1995). Deep-Sea Research II 42: 1519- 1531

Item Type
Conference (Poster)
Primary Division
Primary Topic
Publication Status
Event Details
Goldschmidt 2017, 13 Aug 2017 - 20 Aug 2017, Paris.
Eprint ID
Cite as
Valk, O. , Gdaniec, S. , Rutgers v. d. Loeff, M. , Geibert, W. , Smethie, W. , Moran, B. , Lepore, K. , Edwards, R. , Lu, Y. and Rijkenberg, M. J. (2017): 231Pa and 230Th in the Arctic Ocean 1991-2015: Changes in the Eurasian and Makarov Basins , Goldschmidt 2017, Paris, 13 August 2017 - 20 August 2017 .

[thumbnail of OV-Goldschmidt.pdf]

Download (1MB) | Preview
Cite this document as:

Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email

Geographical region

Research Platforms

ARK > XXIX > 3

Edit Item Edit Item