International Ocean Discovery Program; Expedition 361 preliminary report; South African climates (Agulhas LGM density profile); 30 January-31 March 2016

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doi: 10.14379/iodp.pr.361.2016
Author(s): Hall, Ian R.; Hemming, Sidney R.; LeVay, Leah J.; Barker, Stephen R.; Berke, Melissa A.; Brentegani, Luna; Caley, Thibaut; Cartagena-Sierra, Alejandra; Charles, Christopher D.; Coenen, Jason J.; Crespin, Julien G.; Franzese, Allison M.; Gruetzner, Jens; Han Xibin; Hins, Sophia K. V.; Jimenez Espejo, Francisco J.; Just, Janna; Koutsodendris, Andreas; Kubota, Kaoru; Lathika, Nambiyathodi; Norris, Richard D.; Pereira dos Santos, Thiago; Robinson, Rebecca; Rolison, John M.; Simon, Margit H.; Tangunan, Deborah; van der Lubbe, Jeroen J. L.; Yamane, Masako; Zhang Hucai
International Ocean Discovery Program, Expedition 361 Scientists, College Station, TX
Author Affiliation(s): Primary:
Cardiff University, Department of Earth Sciences, Cardiff, United Kingdom
Other:
Lamont-Doherty Earth Observatory, United States
International Ocean Discovery Program, United States
University of Notre Dame, United States
University of Technology Queensland, Australia
University of Bordeaux, France
Scripps Institution of Oceanography, United States
Northern Illinois University, United States
CUNY, Hostos Community College, United States
Alfred-Wegener-Institut for Polar and Marine Research, Germany
State Oceanic Adminstration, China
California Institute of Technology, United States
Japan Agency for Marine-Earth Science and Technology, Japan
Universität Köln, Germany
University of Heidelberg, Germany
University of Tokyo, Japan
National Center for Antarctic and Ocean Research, India
Universidade Federal Fluminense, Germany
University of Rhode Island, United States
University of Otago, New Zealand
Uni Research Climate, Norway
University of Bremen, Germany
University of Amsterdam, Netherlands
Yunnan Normal University, China
Source: Preliminary Report - International Ocean Discovery Program, Vol.361, 46p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2372-9562
Note: In English. 177 refs.
Summary: International Ocean Discovery Program (IODP) Expedition 361 drilled six sites on the southeast African margin and in the Indian-Atlantic ocean gateway, southwest Indian Ocean, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ∼5 my. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that act as control mechanisms on the basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the sensitivity of the Agulhas Current to climatic changes during the Pliocene-Pleistocene, to determine the dynamics of the Indian-Atlantic gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of the Ancillary Project Letter, consisting of high-resolution interstitial water samples that will constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that span from 0 to between ∼0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Africa; Agulhas Current; Algae; Atlantic Meridional Overturning Circulation; Atlantic Ocean; Biostratigraphy; Cenozoic; Chemostratigraphy; Climate effects; Continental margin; Cores; Currents; Expedition 361; Foraminifera; IODP Site U1474; IODP Site U1475; IODP Site U1476; IODP Site U1477; IODP Site U1478; IODP Site U1479; Indian Ocean; International Ocean Discovery Program; Invertebrata; Last glacial maximum; Lithostratigraphy; Magnetostratigraphy; Marine sediments; Microfossils; Mozambique Channel; Nannofossils; Neogene; Ocean circulation; Ocean currents; Paleo-oceanography; Paleoclimatology; Paleomagnetism; Physical properties; Plantae; Pleistocene; Pliocene; Protista; Quaternary; Sediments; South Atlantic; Southeast Atlantic; Southern Africa; Tertiary
Coordinates: S311300 S311300 E0313243 E0313243
S412537 S412537 E0251538 E0251538
S154915 S154915 E0414607 E0414607
S192117 S192117 E0365454 E0365454
S254916 S254916 E0344610 E0344610
S350332 S350332 E0172404 E0172404
Record ID: 2016051681
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