HR: 1330h
AN: PP42A-0861    [PDF]
TI: Evidence for increased ventilation in the Antarctic Intermediate Waters During the Deglaciation in the Northern Tasman Sea, South West Pacific
AU: * Bostock, H C
EM: helenb@geology.anu.edu.au
AF: Department of Geology, Australian National University, Canberra, ACT 0200 Australia
AU: Opdyke, B N
EM: bno@geology.anu.edu.au
AF: Department of Geology, Australian National University, Canberra, ACT 0200 Australia
AB: Stable isotopes of planktonic and benthic foraminifera from the Capricorn Channel, southern Great Barrier Reef, were analysed to determine changes in ocean circulation in the surface to intermediate waters of the northern Tasman Sea, SW Pacific, during the late Quaternary. Core FR 97/1 GC-12 is located on the continental slope where the core of the Antarctic Intermediate water (AAIW) impinges, presently between 600 and 1100 mbsl in this region and has a high sedimentation rate (average 10cm/kyr). The Dd13C benthic-planktonic gradient appears to change rapidly over the glacial/ interglacial transition. A large Dd13C gradient (1.2%) between the planktonic foraminifera in the surface waters and the benthics from the AAIW exists during the glacial, and an intermediate gradient (0.4%) exists during the Holocene. However during the last deglaciation (Termination 1), the gradient is reduced to ~ 0%. We suggest that variations in the dominance and direction of AAIW, and increased oceanic ventilation rates during the deglaciation can account for these changes in Dd13C.
DE: 4267 Paleoceanography
DE: 4283 Water masses
DE: 4855 Plankton
DE: 4870 Stable isotopes
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting