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Marine Pollution Bulletin, 2011
Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now ... more Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now dominate Pb supply to the oceans. However, the Pb content of sediments across the equatorial Pacific region is relatively unknown, and data exist only for deep sea sites where Pb deposition lags surface water inputs by up to a century. Here we present ICP-MS analyses of Pb of a core from a lagoon at Palmyra Atoll, northern Line Islands, that spans approximately the past 160 years. The non-bioturbated sediments of the euxinic lagoon, coupled with rapid rates of deposition, provide a unique fine-scale record of atmospheric Pb supply at a remote Pacific location. These first observations of historic Pb sedimentation in an atoll lagoon reveal a 63-fold increase in Pb flux to sediments during the past century and correlate directly with the North American consumption of leaded gasoline that began in 1926.
![Research paper thumbnail of Paleo-oceanographic and -climatic reconstruction in the Southwest Pacific [ODP Site 1123] during MIS 11](https://attachments.academia-assets.com/109492517/thumbnails/1.jpg)
](Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interg... more Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interglacial periods due to its duration and orbital geometry, both of which have previously been cited as evidence that MIS 11 may be a suitable analogue to project future climate. This study aims to evaluate this prolonged warm period at a key site in the sparsely studied Southwest Pacific Ocean at Ocean Drilling Program [ODP] 1123. This cored site, situated at 3290 m water depth on the northern flank of the Chatham Rise, straddles the northern limit of the modern Subtropical Front, 1100 km east of New Zealand, where sediments record strong subtropical and subpolar signals over interglacial to glacial cycles. Two species of planktonic foraminifera were analysed, Globigerinoides ruber and Globigerina bulloides [Gs. ruber and Gg. bulloides], for trace elements and size-normalised test weights [SNW; Gg. bulloides only] in order to reconstruct ocean temperature, chemistry, structure and circulation during MIS 11. Gg. bulloides was found to have anomalously low SNW [~50% compared to modern specimens] implying either [i] poor calcification environment due to low CO 3-2 concentrations, or [ii] post-mortem alteration either in the deep water column or ocean floor environment. Traditional dissolution proxies for ODP 1123 do not indicate significant dissolution during MIS 11. Nevertheless, the inception of modern carbonate platforms and reefs at this time leads to the hypothesis that CO 3-2 concentrations in the surface ocean were low due to a shifting in the locus of carbonate production, and this is a potential cause, amongst other possibilities, of the low SNW in Gg. bulloides. However, calcification in a low CO 3-2 concentration ocean does not appear to have significantly affected the geochemical proxies utilised in this study [Mg/Ca-derived paleo-ocean temperatures, δ 18 O and micro-nutrients Mn/Ca and Zn/Ca ratios as water-mass tracers] based on comparison with a similar study on younger sediments in the same core. The temperature difference between Gs. ruber and Gg. bulloides is the same as the modern temperature difference at ODP 1123, implying that Gs.
![Research paper thumbnail of Paleo-oceanographic and -climatic reconstruction in the Southwest Pacific [ODP Site 1123] during MIS 11](https://attachments.academia-assets.com/76298984/thumbnails/1.jpg)
](Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interg... more Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interglacial periods due to its duration and orbital geometry, both of which have previously been cited as evidence that MIS 11 may be a suitable analogue to project future climate. This study aims to evaluate this prolonged warm period at a key site in the sparsely studied Southwest Pacific Ocean at Ocean Drilling Program [ODP] 1123. This cored site, situated at 3290 m water depth on the northern flank of the Chatham Rise, straddles the northern limit of the modern Subtropical Front, 1100 km east of New Zealand, where sediments record strong subtropical and subpolar signals over interglacial to glacial cycles. Two species of planktonic foraminifera were analysed, Globigerinoides ruber and Globigerina bulloides [Gs. ruber and Gg. bulloides], for trace elements and size-normalised test weights [SNW; Gg. bulloides only] in order to reconstruct ocean temperature, chemistry, structure and circulation during MIS 11. Gg. bulloides was found to have anomalously low SNW [~50% compared to modern specimens] implying either [i] poor calcification environment due to low CO 3-2 concentrations, or [ii] post-mortem alteration either in the deep water column or ocean floor environment. Traditional dissolution proxies for ODP 1123 do not indicate significant dissolution during MIS 11. Nevertheless, the inception of modern carbonate platforms and reefs at this time leads to the hypothesis that CO 3-2 concentrations in the surface ocean were low due to a shifting in the locus of carbonate production, and this is a potential cause, amongst other possibilities, of the low SNW in Gg. bulloides. However, calcification in a low CO 3-2 concentration ocean does not appear to have significantly affected the geochemical proxies utilised in this study [Mg/Ca-derived paleo-ocean temperatures, δ 18 O and micro-nutrients Mn/Ca and Zn/Ca ratios as water-mass tracers] based on comparison with a similar study on younger sediments in the same core. The temperature difference between Gs. ruber and Gg. bulloides is the same as the modern temperature difference at ODP 1123, implying that Gs.
Marine Pollution Bulletin, 2011
Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now ... more Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now dominate Pb supply to the oceans. However, the Pb content of sediments across the equatorial Pacific region is relatively unknown, and data exist only for deep sea sites where Pb deposition lags surface water inputs by up to a century. Here we present ICP-MS analyses of Pb of a core from a lagoon at Palmyra Atoll, northern Line Islands, that spans approximately the past 160 years. The non-bioturbated sediments of the euxinic lagoon, coupled with rapid rates of deposition, provide a unique fine-scale record of atmospheric Pb supply at a remote Pacific location. These first observations of historic Pb sedimentation in an atoll lagoon reveal a 63-fold increase in Pb flux to sediments during the past century and correlate directly with the North American consumption of leaded gasoline that began in 1926.
Marine Pollution Bulletin, 2011
Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now ... more Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now dominate Pb supply to the oceans. However, the Pb content of sediments across the equatorial Pacific region is relatively unknown, and data exist only for deep sea sites where Pb deposition lags surface water inputs by up to a century. Here we present ICP-MS analyses of Pb of a core from a lagoon at Palmyra Atoll, northern Line Islands, that spans approximately the past 160 years. The non-bioturbated sediments of the euxinic lagoon, coupled with rapid rates of deposition, provide a unique fine-scale record of atmospheric Pb supply at a remote Pacific location. These first observations of historic Pb sedimentation in an atoll lagoon reveal a 63-fold increase in Pb flux to sediments during the past century and correlate directly with the North American consumption of leaded gasoline that began in 1926.
Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interg... more Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interglacial periods due to its duration and orbital geometry, both of which have previously been cited as evidence that MIS 11 may be a suitable analogue to project future climate. This study aims to evaluate this prolonged warm period at a key site in the sparsely studied Southwest Pacific Ocean at Ocean Drilling Program [ODP] 1123. This cored site, situated at 3290 m water depth on the northern flank of the Chatham Rise, straddles the northern limit of the modern Subtropical Front, 1100 km east of New Zealand, where sediments record strong subtropical and subpolar signals over interglacial to glacial cycles. Two species of planktonic foraminifera were analysed, Globigerinoides ruber and Globigerina bulloides [Gs. ruber and Gg. bulloides], for trace elements and size-normalised test weights [SNW; Gg. bulloides only] in order to reconstruct ocean temperature, chemistry, structure and circulation during MIS 11. Gg. bulloides was found to have anomalously low SNW [~50% compared to modern specimens] implying either [i] poor calcification environment due to low CO 3-2 concentrations, or [ii] post-mortem alteration either in the deep water column or ocean floor environment. Traditional dissolution proxies for ODP 1123 do not indicate significant dissolution during MIS 11. Nevertheless, the inception of modern carbonate platforms and reefs at this time leads to the hypothesis that CO 3-2 concentrations in the surface ocean were low due to a shifting in the locus of carbonate production, and this is a potential cause, amongst other possibilities, of the low SNW in Gg. bulloides. However, calcification in a low CO 3-2 concentration ocean does not appear to have significantly affected the geochemical proxies utilised in this study [Mg/Ca-derived paleo-ocean temperatures, δ 18 O and micro-nutrients Mn/Ca and Zn/Ca ratios as water-mass tracers] based on comparison with a similar study on younger sediments in the same core. The temperature difference between Gs. ruber and Gg. bulloides is the same as the modern temperature difference at ODP 1123, implying that Gs.
Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interg... more Marine Isotope Stage 11 [424 to 374 ka] is unique compared to most other recent Quaternary interglacial periods due to its duration and orbital geometry, both of which have previously been cited as evidence that MIS 11 may be a suitable analogue to project future climate. This study aims to evaluate this prolonged warm period at a key site in the sparsely studied Southwest Pacific Ocean at Ocean Drilling Program [ODP] 1123. This cored site, situated at 3290 m water depth on the northern flank of the Chatham Rise, straddles the northern limit of the modern Subtropical Front, 1100 km east of New Zealand, where sediments record strong subtropical and subpolar signals over interglacial to glacial cycles. Two species of planktonic foraminifera were analysed, Globigerinoides ruber and Globigerina bulloides [Gs. ruber and Gg. bulloides], for trace elements and size-normalised test weights [SNW; Gg. bulloides only] in order to reconstruct ocean temperature, chemistry, structure and circulation during MIS 11. Gg. bulloides was found to have anomalously low SNW [~50% compared to modern specimens] implying either [i] poor calcification environment due to low CO 3-2 concentrations, or [ii] post-mortem alteration either in the deep water column or ocean floor environment. Traditional dissolution proxies for ODP 1123 do not indicate significant dissolution during MIS 11. Nevertheless, the inception of modern carbonate platforms and reefs at this time leads to the hypothesis that CO 3-2 concentrations in the surface ocean were low due to a shifting in the locus of carbonate production, and this is a potential cause, amongst other possibilities, of the low SNW in Gg. bulloides. However, calcification in a low CO 3-2 concentration ocean does not appear to have significantly affected the geochemical proxies utilised in this study [Mg/Ca-derived paleo-ocean temperatures, δ 18 O and micro-nutrients Mn/Ca and Zn/Ca ratios as water-mass tracers] based on comparison with a similar study on younger sediments in the same core. The temperature difference between Gs. ruber and Gg. bulloides is the same as the modern temperature difference at ODP 1123, implying that Gs.
Marine Pollution Bulletin, 2011
Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now ... more Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now dominate Pb supply to the oceans. However, the Pb content of sediments across the equatorial Pacific region is relatively unknown, and data exist only for deep sea sites where Pb deposition lags surface water inputs by up to a century. Here we present ICP-MS analyses of Pb of a core from a lagoon at Palmyra Atoll, northern Line Islands, that spans approximately the past 160 years. The non-bioturbated sediments of the euxinic lagoon, coupled with rapid rates of deposition, provide a unique fine-scale record of atmospheric Pb supply at a remote Pacific location. These first observations of historic Pb sedimentation in an atoll lagoon reveal a 63-fold increase in Pb flux to sediments during the past century and correlate directly with the North American consumption of leaded gasoline that began in 1926.