HR: 1340h
AN: PP13C-1423    [Abstracts]
TI: A high-resolution, Holocene record of climate variability from the Eastern North Pacific
AU: * Ivanochko, T S
EM: tivanoch@eos.ubc.ca
AF: University of British Columbia, Department of Earth and Ocean Sciences 6339 Stores Rd, Vancouver, BC V6T 1Z4, Canada
AU: Calvert, S E
EM: scalvert@eos.ubc.ca
AF: University of British Columbia, Department of Earth and Ocean Sciences 6339 Stores Rd, Vancouver, BC V6T 1Z4, Canada
AU: Marshall, D
EM: marshall@sfu.ca
AF: Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
AU: Thomson, R E
EM: ThomsonR@pac.dfo-mpo.gc.ca
AF: Institute of Ocean Sciences, 9860 West Saanich Road, Sidney, BC V8L 4B2,
AU: Pedersen, T F
EM: tfp@uvic.ca
AF: University of Victoria, Elliot 166, PO Box 3055, Victoria, BC V8W 3P6, Canada
AB: Determining climate variations over the Holocene requires high-resolution records with well-developed age models. One such record is provided by marine sediments from Effingham Inlet, an anoxic fjord on the west coast of Vancouver Island, Canada. The present-day regional climate is dominated by the Aleutian Low during winter months and an associated downwelling-favorable wind regime, and by the North Pacific High and upwelling- favourable winds during summer months. Forty-six 14C AMS dates, determined from terrestrial plant material, comprise the new age model for the Effingham core. Downcore sampling at both 5 cm (20 yr) and 1.5 cm (6 yr) resolution indicates high frequency variability at this site over last 14,000 years. Spectral analysis of % opal, a proxy of productivity in the basin, has identified two strong cycles of environmental change identified with the bi- decadal and penta-decadal changes in the Pacific Decadal Oscillation (PDO) and the strength of the Aleutian Low as previously described by Minobe et al. (1999). Comparisons of the Effingham Inlet data with delta180 records from Jellybean Lake (SW Yukon) and the Port McNeil Speleothem (northeastern Vancouver Island) suggest broad regional coherence between productivity in Effingham Inlet, changes in the Aleutian Low strength, and air temperature. In addition to high frequency variations, six periods of diminished basin productivity are identified, each lasting approximately 500 years.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting