Paleoceanography of southern high latitudes and interhemispheric comparison during the last climatic cycle

Conference · Tue Jan 09 04:00:00 EST 1990 · EOS, Transactions, American Geophysical Union; (United States)

OSTI ID:6666621

Labracheri, M; Pichon, J J; Duprat, J; Turon, J L; Grousset, F E ^[1]; Labeyrie, L D ^[2]

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1. Univ. Bordeaux I. (France)
2. CFR Lab. CNRS-CEA, Gif-sur-Yvette (France)

Continuous records of high-latitude climate variability are contained in deep-sea cores from two transects (N-S and E-W) through the Southern Indian Ocean. Their position within the polar front system and south of this major boundary between subtropical and antarctic surface waters, makes them ideal for the acquisition of new information on hydrologic changes in this area of the Southern Ocean. A detailed comparison of the oxygen isotopic composition of planktonic and benthic foraminifera, abundance of the radiolarian species Cycladophora davisiana and surface-water temperatures (SST) estimated by transfer-functions derived from the distribution of foraminifera or diatoms in the same sediments, provide distinctive oceanographic signals to reconstruct climatic responses of this part of the climatic system. Using the transfer-function developed from the diatom distribution, SST reconstructed for the last climatic cycle around 55[degrees]S show a striking similarity with air temperature changes over the Antarctic ice sheet. Disagreements already observed by Joizel et al. (1987) at the Transition 6/5 may be due to time scale differences that still need to be resolved. The initiation of the glacial time (Transition 5e/5d) in the Southern Ocean is marked by an abnormal cooling in SST and an early response between 42[degrees] and 55[degrees]S. At this time the ice volume remains relatively low while that in the North-eastern Atlantic Ocean the climatic deterioration occurs with a delay of some keys after the onset of glaciation over the Laurentide ice sheet.

• OSTI ID: 6666621
• Report Number(s): CONF-9002174--
• Conference Information: Journal Name: EOS, Transactions, American Geophysical Union; (United States) Journal Volume: 71:2
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
540310 -- Environment
Aquatic-- Basic Studies-- (1990-)
ALGAE
ANIMALS
ANTARCTIC REGIONS
AQUATIC ORGANISMS
ATLANTIC OCEAN
CHROMOPHYCOTA
CLIMATES
CLIMATIC CHANGE
COOLING
DIATOMS
EARTH ATMOSPHERE
EARTH PLANET
ELEMENTS
FORAMINIFERA
GEOGRAPHICAL VARIATIONS
HYDROLOGY
ICE
INDIAN OCEAN
INVERTEBRATES
LATITUDE EFFECT
MICROORGANISMS
NONMETALS
NORTHERN HEMISPHERE
OCEANOGRAPHY
OXYGEN
PALEOCLIMATOLOGY
PALEONTOLOGY
PLANETS
PLANTS
POLAR REGIONS
PROTOZOA
SARCODINA
SEAS
SEDIMENTS
SOUTHERN HEMISPHERE
SURFACE WATERS
TEMPERATURE MEASUREMENT
VARIATIONS