HR: 0800h
AN: PP11A-0239    [Abstracts]
TI: Late Neogene Changes In Atlantic-Pacific Intermediate And Deep-Water δ¹³C gradients
AU: * Sturm, A
EM: Arne.Sturm@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, Am Alten Hafen 26, Bremerhaven, 27568, Germany
AU: Tiedemann, R
EM: Ralf.Tiedemann@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, Am Alten Hafen 26, Bremerhaven, 27568, Germany
AU: Silke, S
EM: Silke.Steph@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, Am Alten Hafen 26, Bremerhaven, 27568, Germany
AB: This study compares intermediate and deep-water δ¹³C records from the Atlantic/Caribbean (sites 704, 925/926, 982, 1000) and the east Pacific (sites 846, 1236, 1237, 1241) for the time interval from 8.8 to 2.0 Ma. The comparison reflects changes in Atlantic-Pacific nutrient distributions and thus changes in thermohaline circulation. The δ¹³C gradient between the deep Atlantic and the deep Pacific remained relatively constant from 7-3 Ma and decreased after 3 Ma. At the intermediate water level, Pacific and Atlantic δ¹³C values were similar prior to 4.2 Ma; the difference increased after 4.2 Ma due to decreasing upper Atlantic nutrient concentrations. The δ¹³C values between the shallow Atlantic and the eastern Pacific are very similar prior to 8.5 Ma. After 8.5 Ma, the Atlantic-Pacific difference strongly increased until 5.9 Ma. The timing of the observed changes in Atlantic-Pacific δ¹³C gradients suggest influences from ocean gateway dynamics.
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting