Pigments in sediments beneath recently collapsed ice shelves: The case of Larsen A and B shelves, Antarctic Peninsula

9 pages, 6 figures, 6 tables In March 2002, 3200 km2 of the Larsen B ice shelf collapsed off the Eastern Antarctic Peninsula (EAP). In the austral summer of 2006, sea floor sediment was recovered beneath the extinct Larsen B ice shelf and in a region off the Northern Antarctic Peninsula (NAP), which...

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Bibliographic Details
Published in:Journal of Sea Research
Main Authors: Sañé, Elisabet, Isla, Enrique, Grémare, Antoine, Gutt, Julian, Vétion, Gilles, DeMaster, D.J.
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2011
Subjects:
Chlorophyll
Sediment
Antarctic Peninsula
Climate change
Antarctic
Austral
Antarc*
Ice Shelf
Ice Shelves
Online Access:http://hdl.handle.net/10261/46115
https://doi.org/10.1016/j.seares.2010.07.005
Description
Summary:9 pages, 6 figures, 6 tables In March 2002, 3200 km2 of the Larsen B ice shelf collapsed off the Eastern Antarctic Peninsula (EAP). In the austral summer of 2006, sea floor sediment was recovered beneath the extinct Larsen B ice shelf and in a region off the Northern Antarctic Peninsula (NAP), which has been free of ice shelves for more than 1000 yr. To assess changes in the chemical composition of the sediment after ice shelf collapses, chlorophylls and pheophytins were measured in sediment cores at six stations. This is the first time that chlorophyll pigments have been analysed in sediment samples from regions under recently collapsed ice shelves. Five years after the ice shelf collapse, Chla and Chlc concentrations were similar in the interfacial sediment (upper 1 cm) of NAP and EAP regions. However, in EAP Chla and Chlc concentrations decreased more rapidly with depth in the sediment column and were negligible below 2 cm depth. The high Chla to Pheoa ratios indicated that sedimentary pigments found in EAP had undergone limited degradation suggesting that they were locally produced rather than laterally advected. Complementary information from excess 210Pb activity and diatom valve distributions provided further evidence that the pigment fluxes to the seabed in EAP took place only after the ice shelf collapse This study was supported by the Spanish Ministry of Science and Innovation, through the project CLIMANT (POL2006- 06399) and the graduate program fellowship FPU AP 2005-5060. Peer reviewed

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