Articles | Volume 16, issue 1
Ocean Sci., 16, 221–234, 2020
https://doi.org/10.5194/os-16-221-2020
Ocean Sci., 16, 221–234, 2020
https://doi.org/10.5194/os-16-221-2020

Research article 14 Feb 2020

Research article | 14 Feb 2020

Decrease in 230Th in the Amundsen Basin since 2007: far-field effect of increased scavenging on the shelf?

Ole Valk et al.

Data sets

Thorium isotopes in the water column in Amundsen Basin during POLARSTERN cruises PS70 (ARK-XXII/2) in 2007 and PS94 (ARK-XXIX/3) in 2015. O. Valk, M. M. Rutgers van der Loeff, W. Geibert, S. Gdaniec, S. B. Moran, K. Lepore, R. L. Edwards, Y. Lu, V. Puigcorbé, N. Casacuberta, R. Paffrath, W. Smethie, and M. Roy-Barman, https://doi.org/10.1594/PANGAEA.908068

Thorium isotopes in the water column in Nansen Basin during POLARSTERN cruises PS70 (ARK-XXII/2) in 2007 and PS94 (ARK-XXIX/3) in 2015 O. Valk, M. M. Rutgers van der Loeff, and W. Geibert https://doi.org/10.1594/PANGAEA.893871

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Short summary
After 2007 230Th decreased significantly in the central Amundsen Basin. This decrease is accompanied by a circulation change, indicated by changes in salinity. Ventilation of waters is most likely not the reason for the observed depletion in 230Th as atmospherically derived tracers do not reveal an increase in ventilation rate. It is suggested that these interior waters have undergone enhanced scavenging of Th during transit from Fram Strait and the Barents Sea to the central Amundsen Basin.