Organic carbon accumulation in the South Atlantic Ocean

DOI

A compilation of 1118 surface sediment samples from the South Atlantic was used to map modern seafloor distribution of organic carbon content in this ocean basin. Using new data on Holocene sedimentation rates, we estimated the annual organic carbon accumulation in the pelagic realm (>3000 m water depth) to be approximately 1.810*12 g C/year. In the sediments underlying the divergence zone in the Eastern Equatorial Atlantic (EEA), only small amounts of organic carbon accumulate in spite of the high surface water productivity observed in that area. This implies that in the Eastern Equatorial Atlantic, organic carbon accumulation is strongly reduced by efficient degradation of organic matter prior to its burial.During the Last Glacial Maximum (LGM), accumulation of organic carbon was higher than during the mid-Holocene along the continental margins of Africa and South America (Brazil) as well as in the equatorial region. In the Eastern Equatorial Atlantic in particular, large relative differences between LGM and mid-Holocene accumulation rates are found. This is probably to a great extent due to better preservation of organic matter related to changes in bottom water circulation and not just a result of strongly enhanced export productivity during the glacial period. On average, a two- to three-fold increase in organic carbon accumulation during the LGM compared to mid-Holocene conditions can be deduced from our cores. However, for the deep-sea sediments this cannot be solely attributed to a glacial productivity increase, as changes in South Atlantic deep-water circulation seem to result in better organic carbon preservation during the LGM.

Supplement to: Mollenhauer, Gesine; Schneider, Ralph R; Jennerjahn, Tim C; Müller, Peter J; Wefer, Gerold (2004): Organic carbon accumulation in the South Atlantic Ocean: its modern, mid-Holocene and last glacial distribution. Global and Planetary Change, 40(3-4), 249-266

Identifier
DOI https://doi.org/10.1594/PANGAEA.735988
Related Identifier https://doi.org/10.1016/j.gloplacha.2003.08.002
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.735988
Provenance
Creator Mollenhauer, Gesine (ORCID: 0000-0001-5138-564X); Schneider, Ralph R ORCID logo; Jennerjahn, Tim C ORCID logo; Müller, Peter J; Wefer, Gerold ORCID logo
Publisher PANGAEA
Publication Year 2004
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 5 datasets
Discipline Geosciences; Natural Sciences
Spatial Coverage (-59.733W, -49.999S, 19.760E, 10.000N); South Atlantic Ocean; Gulf of Guinea; Benguela Current, South Atlantic Ocean; Equatorial Atlantic; Victoria - Victoria; Argentinian Basin; Rio Grande Rise; South Atlantic Ridge; Angola Basin; Cape Basin; Rio de Janeiro - Salvador - Recife; South Atlantic; Atlantic Ocean; Walvis Ridge; Walvis Ridge, Southeast Atlantic Ocean; Guinea Basin; Brazil Basin; Romanche fracture zone; Kongo delta; Congo Fan; Northern Guinea Basin; Southwest Guinea Basin; Cardno Seamount; West Angola Basin; Mid Atlantic Ridge; East Brazil Basin; Amazon Fan; off Kunene; Namibia Continental Margin; Namibia continental slope; South African margin; Argentine Basin; Angola Diapir Field; Angola Benguela Front; Hunter Channel; Slope off Argentina; Uruguay continental margin; Santos Plateau; Northern Brasil-Basin; Western Equatorial Atlantic; Sierra Leone Rise; NE-Brazilian continental margin; Southern Cape Basin; Northern Cape Basin; Vema Channel; Continental slope off Brazil; Northeast Brasilian Margin; Amazon Shelf/Fan; Eastern Niger fan; NE off San Thome; off northern Gabun; off Cameroon; off Gabun; off south Gabun; northern Congo fan; southern Congo fan; off Angola; western South Atlantic; Central South Atlantic; off Guinea; eastern Romanche Fracture Zone; Sierra Leone Basin/Guinea Basin; off Liberia; NE Atlantic off Liberia; off Cote d Ivoire; off Ghana; off eastern Ghana; off Lagos; off Nigeria; off Nigeria-Delta; Walvis Bay/Namibia; Van Heesen Ridge; Agulhas Basin; Meteor Rise; Atlantic Ridge
Temporal Coverage Begin 1957-03-12T00:00:00Z
Temporal Coverage End 2000-08-20T00:00:00Z