HR: 09:30h
AN: OS11A-07 INVITED     [PDF]
TI: Geochemical Budget for Barium on the Wet Tropical Continental Shelf \& Slope of the Gulf of Papua, Papua New Guinea.
AU: * Brunskill, G J
EM: g.brunskill@aims.gov.au
AF: Australian Institute of Marine Science, PMB 3, Townsville MC, Qld 4810 Australia
AU: Zagorskis, I
EM: i.zagorskis@aims.gov.au
AF: Australian Institute of Marine Science, PMB 3, Townsville MC, Qld 4810 Australia
AU: Pfitzner, J
EM: j.pfitzner@aims.gov.au
AF: Australian Institute of Marine Science, PMB 3, Townsville MC, Qld 4810 Australia
AU: Wu, H
EM:
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AU: Shen, G
EM: glenshen@yahoo.com
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AU: Hamme, R
EM: rmartin@ocean.washington.edu
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AB: Most of the riverine supply rate of Ba to the Gulf of Papua from wet tropical mountains and coastal plains of southern New Guinea is in particulate form. Freshwater dissolved Ba concentrations are low (60 nM), but increase by 4-5 times in the salinity gradient of the upper deltas. This salinity enhanced dissolved Ba may come from suspended and bottom sediment cation exchange, or from groundwater inputs. Ba is also supplied to the water column of the inner shelf from sediment pore water diffusion. The distribution of shelf and slope sedimentary concentrations of Ba is presented, along with estimates of sediment mass accumulation rates from core profiles of excess 210Pb and 137Cs. We estimate that century scale burial of Ba on the inner shelf is less than 25% of total Ba supply from rivers, the remainder being exported to the northern Coral Sea and the New Guinea Coastal Current. Ba removal rates in the northern Coral Sea, as estimated from sediment traps and a few cores, are small but cover a large area. Maximum Ba concentrations in sediment are found in deep (greater than 2000 m) water of the northern Coral Sea, where sediment accumulation rates are very low. Variations in sediment core Ba profiles appears to be due to variations in the ratio of supply rate of river aluminosilicate minerals to marine carbonate supply, and not easily related to a proxy for productivity.
UR: http://www.aims.gov.au/tropics
DE: 1050 Marine geochemistry (4835, 4850)
DE: 4219 Continental shelf processes
DE: 4805 Biogeochemical cycles (1615)
DE: 4863 Sedimentation
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting