Curtis, Kathryn Venz (2004): Oceanic deep-water circulation and climate during the late Neogene

Leg/Site/Hole:
ODP 138
ODP 162
ODP 177
ODP 177 1090
ODP 138 849
ODP 162 982
Identifier:
2005-056721
georefid

0-496-03475-8
isbn

Creator:
Curtis, Kathryn Venz
author

Identification:
Oceanic deep-water circulation and climate during the late Neogene
2004
134 pp.
Deep-water circulation was reconstructed for the late neogene by comparing carbon isotopic records of benthic foraminifera from the North Atlantic (NA), Southern Ocean (SO), and deep Pacific Basins. The history of NA intermediate water was studied using delta (super 13) C at Ocean Drilling Program (ODP) Site 982. Production of Glacial North Atlantic Intermediate Water (GNAIW) was enhanced during glacial periods of the late Pleistocene whereas production of lower North Atlantic Deep Water (NADW) was much reduced. During terminations, production of GNAIW ceased briefly until upper-NADW production resumed under full interglacial conditions. The magnitude of benthic delta (super 13) C minima, ice-rafted debris maxima at Site 982, and glacial suppression of NADW may be related to the spatial and seasonal extent of sea ice in the Nordic Seas. The history of deep-water circulation in the Atlantic sector of the SO was examined using a delta (super 13) C record from ODP Site 1090 in the South Atlantic (SA). At 1.55 Ma, glacial delta (super 13) C values in the SA sector of the SO became significantly lower than those in the deep Pacific, establishing a pattern that persisted throughout the late Pleistocene. Lower delta (super 13) C values in the SO may have resulted from expansion of sea ice and reduced ventilation of deep-water during glacial periods. Accompanying this change in SO deep-water circulation was enhanced interhemispheric coupling between the NA and SA. (modif. auth. abstr.)
English
Thesis or Dissertation
Coverage:Geographic coordinates:
North:57.3100
West:-110.3111East: 8.5359
South:-42.5449

Stratigraphy; Isotope geochemistry; Atlantic Ocean; benthic taxa; C-13/C-12; carbon; Cenozoic; East Pacific; Foraminifera; glaciation; ice; Invertebrata; isotope ratios; isotopes; Leg 138; Leg 162; Leg 177; marine environment; microfossils; Neogene; North Atlantic; North Pacific; Northeast Pacific; Ocean Drilling Program; ODP Site 1090; ODP Site 849; ODP Site 982; Pacific Ocean; paleo-oceanography; paleoclimatology; paleoenvironment; Pleistocene; Protista; Quaternary; Rockall Bank; sea ice; South Atlantic; Southeast Atlantic; Southern Ocean; stable isotopes; Tertiary; upper Neogene;

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