Intercalibration studies of short-lived thorium-234 in the water column and marine particles

View/ Open
Date
2012-09Author
Maiti, Kanchan
Concept link
Buesseler, Ken O.
Concept link
Pike, Steven M.
Concept link
Benitez-Nelson, Claudia R.
Concept link
Cai, Pinghe
Concept link
Chen, Weifang
Concept link
Cochran, Kirk
Concept link
Dai, Minhan
Concept link
Dehairs, Frank
Concept link
Gasser, Beat
Concept link
Kelly, Roger P.
Concept link
Masqué, Pere
Concept link
Miller, Lisa A.
Concept link
Miquel, Juan Carlos
Concept link
Moran, S. Bradley
Concept link
Morris, Paul J.
Concept link
Peine, Florian
Concept link
Planchon, Frederic
Concept link
Renfro, Alisha A.
Concept link
Rutgers van der Loeff, Michiel M.
Concept link
Santschi, Peter H.
Concept link
Turnewitsch, Robert
Concept link
Waples, James T.
Concept link
Xu, Chen
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/6631As published
https://doi.org/10.4319/lom.2012.10.631DOI
10.4319/lom.2012.10.631Abstract
Intercomparision of 234Th measurements in both water and particulate samples was carried out between 15 laboratories worldwide, as a part of GEOTRACES inter-calibration program. Particulate samples from four different stations namely BATS (both shallow and deep) and shelf station (shallow) in Atlantic and SAFE (both shallow and deep) and Santa Barbara station (shallow) in Pacific were used in the effort. Particulate intercalibration results indicate good agreement between all the participating labs with data from all labs falling within the 95% confidence interval around the mean for most instances. Filter type experiments indicate no significant differences in 234Th activities between filter types and pore sizes (0.2-0.8 μm). The only exception are the quartz filters, which are associated with 10% to 20% higher 234Th activities attributed to sorption of dissolved 234Th. Flow rate experiments showed a trend of decreasing 234Th activities with increasing flow rates (2-9 L min-1) for > 51 μm size particles, indicating particle loss during the pumping process. No change in 234Th activities on small particles was observed with increasing flow-rates. 234Th intercalibration results from deep water samples at SAFe station indicate a variability of < 3% amongst labs while dissolved 234Th data from surface water at Santa Barbara Station show a less robust agreement, possibly due to the loss of 234Th from decay and large in-growth corrections as a result of long gap between sample collection and processing.
Description
Author Posting. © Association for the Sciences of Limnology and Oceanography, 2012. This article is posted here by permission of Association for the Sciences of Limnology and Oceanography for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography: Methods 10 (2012): 631-644, doi:10.4319/lom.2012.10.631.