HR: 0800h
AN: PP31B-0415    [Abstracts]
TI: Salinity and Temperature Reconstruction from Oxygen Isotopes and Mg/Ca in Benthic Foraminifera in the NE Pacific margin for the Late Holocene
AU: * Herguera, J
EM: herguera@cicese.mx
AF: Oceanología, CICESE, Km 107 Carretera Transpeninsular, Ensenada, BC 22850, Mexico
AU: Mortyn, G
EM: graham.mortyn@uab.es
AF: Institute of Environmental Science and Technology, Universitat Autonoma de Barcelona, Barcelona, CA 08193, Spain
AU: Herbert, T
EM: Tim_Herbert@brownu.edu
AF: Dept. of Geological Sciences, Brown University, Providence, RI 02912, United States
AU: Charles, C
EM: ccharles@ucsd.edu
AF: Scripps Institution of Oceanography, UCSD, La Jolla, CA 92037, United States
AB: Upper intermediate waters in the North Pacific presently show an equal partitioning between the wind driven (<26.5?) and thermohaline circulation (>26.5-27.3?). The ventilated volumes and ages in the upper wind driven layer are related to the wind stress curl and surface buoyancy fluxes in mid to high latitudes in the North Pacific, in contrast to the deeper thermohaline layers that are more effectively ventilated by direct atmosphere-sea exchange during convective formation of Subantarctic mode and Antarctic Intermediate Waters the precursors of Pacific Intermediate Waters (PIW) in the North Pacific. These upper and lower intermediate are clearly identified by its temperature and salinity properties that can be used to trace their sources and mixing paths along isopicnals. A precise characterization of temperature and salinity properties with depth is fundamental in order to characterize and track past changes in sources and mixing paths which will alow to reconstruct the past hydrography of these intermediate water masses. Here we will present results from a calibration based on the combined use of Mg/Ca and oxygen isotopic ratios in benthic foraminifera along a depth transect in the NE Pacific in sediments of late Holocene age to characterize the effects of carbonate saturation and early diagenesis in organic carbon rich sediments on the continental margin of Baja California that will aid us to assess the possibility to reconstruct temperature and salinity trajectories further back in the past in these environments.
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1065 Major and trace element geochemistry
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 4924 Geochemical tracers
DE: 4954 Sea surface temperature
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting