Data/hora: 07/06/2024 08:03:43

Provedor de dados: | 5
País: | France
Título: | Not all calcite ballast is created equal: differing effects of foraminiferan and coccolith calcite on the formation and sinking of aggregates
Autores: | Schmidt, K.; De La Rocha, C. L.; Gallinari, Morgane; Cortese, G.
Data: | 2014
Ano: | 2014
Resumo: | Correlation between particulate organic carbon (POC) and calcium carbonate sinking through the deep ocean has led to the idea that ballast provided by calcium carbonate is important for the export of POC from the surface ocean. While this idea is certainly to some extent true, it is worth considering in more nuance, for example, examining the different effects on the aggregation and sinking of POC of small, non-sinking calcite particles like coccoliths and large, rapidly sinking calcite like planktonic foraminiferan tests. We have done that here in a simple experiment carried out in roller tanks that allow particles to sink continuously without being impeded by container walls. Coccoliths were efficiently incorporated into aggregates that formed during the experiment, increasing their sinking speed compared to similarly sized aggregates lacking added calcite ballast. The foraminiferan tests, which sank as fast as 700 md(-1), became associated with only very minor amounts of POC. In addition, when they collided with other, larger, foram-less aggregates, they fragmented them into two smaller, more slowly sinking aggregates. While these effects were certainly exaggerated within the confines of the rolling tanks, they clearly demonstrate that calcium carbonate ballast is not just calcium carbonate ballast -different forms of calcium carbonate ballast have notably different effects on POC aggregation, sinking, and export.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00176/28728/27193.pdf

DOI:10.5194/bg-11-135-2014

https://archimer.ifremer.fr/doc/00176/28728/

Editor: | Copernicus Gesellschaft Mbh
Relação: | info:eu-repo/grantAgreement/EC/FP7/264933/EU//EURO-BASIN
Formato: | application/pdf
Fonte: | Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2014 , Vol. 11 , N. 1 , P. 135-145

Fonte:

info:eu-repo/semantics/openAccess

restricted use