HR: 0800h
AN: PP51F-1379    [Abstracts]
TI: Continental and marine climate records from the Southeast Pacific as inferred from Radiolaria and pollen records from 0 to 90ka at ODP Site 1233
AU: Pisias, N G
EM: npisias@coas.oregonstate.edu
AF: College of Oceanic & Atmospheric Sciences, 104 COAS Admin Bldg, Corvallis, OR 97331-5503 United States
AU: Mix, A C
EM: amix@coas.oregonstate.edu
AF: College of Oceanic & Atmospheric Sciences, 104 COAS Admin Bldg, Corvallis, OR 97331-5503 United States
AU: Weber, M
EM: weber@coas.oregonstate.edu
AF: College of Oceanic & Atmospheric Sciences, 104 COAS Admin Bldg, Corvallis, OR 97331-5503 United States
AU: Heusser, L
AF: Lamont Doherty Earth Observatory, Columbia University, 61 Route 9W, PO Box 1000, Palisades, NY 10964-1000 United States
AU: * Heusser, C H
EM: heusser@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory, Columbia University, 61 Route 9W, PO Box 1000, Palisades, NY 10964-1000 United States
AB: Site 1233 drilled during Leg 202 of the Ocean Drilling Program provides a detailed record of oceanographic and continental climate change in the Southeast Pacific and South American continent. Splits from over 500 samples from Site 1233 were used for detailed radiolarian and pollen species population analysis. Samples were taken at 20cm interval equivalent to temporal resolution of 200 to 400 years. In each sample splits used for pollen analysis abundances of 25 species were determined while in the splits used for radiolarian studies abundances of 41 species were evaluated. Age control is provided by 25 AMS 14C dates (Lamy et al., 2004). From detailed multivariate analysis of these data sets we state the following conclusions: 1) During the past 75kyr the region of the southern Chile coast is not directly influenced by polar water from the Antarctic region. 2) Changes in ocean conditions during this time interval reflect small north-south shifts in the south Pacific transition zone and its impact on the coastal waters of Chile. 3) The ocean and terrestrial climate records extracted from Site 1233 show remarkable similarities to each other as well as to temperature records from the Antarctic. These records suggest that climate variability during the past 75kyr in the Southeast Pacific is tightly coupled at periods longer than 3000 years and not linked directly to changes in the Northern Hemisphere and; 4) the marine and terrestrial climate records from Site 1233 studied here, show no phase shift in response suggesting that ocean/continental vegetation is much more tightly coupled with regional atmospheric changes as indicated by the Antarctic temperature proxy record while the results of Lamy et al., (2004) show a time lag between ocean responses and the Patagonian Ice Sheet suggesting possibly reflecting the long response time of ice versus continental vegetation and oceanic systems.
DE: 4267 Paleoceanography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting