scholarly journals Southwest Pacific Ocean response to a warming world: Using Mg/Ca, Zn/Ca, and Mn/Ca in foraminifera to track surface ocean water masses during the last deglaciation

2013 ◽  
Vol 28 (2) ◽  
pp. 347-362 ◽  
Author(s):  
Julene P. Marr ◽  
Lionel Carter ◽  
Helen C. Bostock ◽  
Annette Bolton ◽  
Euan Smith
Keyword(s):  
Pacific Ocean ◽  
Water Masses ◽  
Ocean Water ◽  
Last Deglaciation ◽  
Southwest Pacific ◽  
Surface Ocean ◽  
Ocean Response ◽  
The Last Deglaciation ◽  
Track Surface ◽  
Warming World

Changes in the rate of ventilation of intermediate and deep water masses in the pacific ocean during the last deglaciation

1988 ◽  
Vol 70 (1-2) ◽  
pp. 108 ◽  
Author(s):  
J.C. Duplessy ◽  
M. Arnold ◽  
N.J. Shackleton ◽  
N. Kallel ◽  
L. Labeyrie ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Deep Water ◽  
Water Masses ◽  
Last Deglaciation ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Last Deglaciation

scholarly journals The Mysterious 14C Decline

Radiocarbon ◽  
2009 ◽  
Vol 51 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Wallace Broecker
Keyword(s):  
Age Differences ◽  
Radiocarbon Dating ◽  
Progressive Increase ◽  
Time Interval ◽  
Last Deglaciation ◽  
Polar Ice ◽  
Radiocarbon Age ◽  
Surface Ocean ◽  
The Past ◽  
The Last Deglaciation

Fundamental to the field of radiocarbon dating is not only the establishment of the temporal record of the calendar age-radiocarbon age offsets but also the development of an understanding of their cause. Although part of the decline in the magnitude of this offset over the past 40,000 can be explained by a drop in 14C production rate associated with a progressive increase in the strength of the Earth's magnetic shielding, it is clear that changes in the distribution of 14C among the Earth's active carbon reservoirs are also required. In particular, the steep 15% decline in the 14C to C ratio in atmospheric CO2 and surface ocean ΣCO2, which occurred in a 3 kyr-duration interval marking the onset of the last deglaciation, appears to require that a very large amount (at least 5000 gigatons) of 14C-deficient carbon was transferred to or within the ocean during this time interval. As no chemical or stable isotope anomaly associated with this injection appears in either the marine sediment or polar ice records, this injection must involve a transfer within the ocean (i.e. a mixing of 2 ocean reservoirs, one depleted in 14C and the other enriched in 14C). Although evidence for the existence of a salt-stabilized glacial-age abyssal ocean reservoir exists, a search based on benthic-planktic age differences and 13C measurements appears to place a limit on its size well below that required to account for the steep 14C decline.

scholarly journals Southwest Pacific Ocean response to a warmer world: Insights from Marine Isotope Stage 5e

2013 ◽  
Vol 28 (3) ◽  
pp. 585-598 ◽  
Author(s):  
G. Cortese ◽  
G. B. Dunbar ◽  
L. Carter ◽  
G. Scott ◽  
H. Bostock ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Marine Isotope Stage ◽  
Southwest Pacific ◽  
Ocean Response

scholarly journals LA-ICP-MS Trace Element Analysis of Planktonic Foraminifera and Application to Marine Isotope Stage 31 in the Southwest Pacific Ocean

2021 ◽  
Author(s):  
◽  
Annette Bolton
Keyword(s):  
Pacific Ocean ◽  
Trace Element ◽  
Planktonic Foraminifera ◽  
Trace Element Analysis ◽  
Element Analysis ◽  
Southwest Pacific ◽  
Surface Ocean ◽  
Icp Ms ◽  
Isotope Record ◽  
Stable Isotope Record

<p><b>Trace element/Ca ratios were measured by LA-ICP-MS in Gs. ruber and N. incompta from a wide range of core top and plankton tow samples in the Southwest Pacific Ocean, with particular focus on linking measured Mg/Ca ratios to observed (near-) surface ocean temperatures. Mean Mg/Ca ratios measured in the ultimate chamber F of Gs. ruber are significantly lower compared to chambers F-2 and F-1, which show no statistical difference. These observations led to the development of three new Mg/Ca – ocean temperature calibrations that can be used to reconstruct SST from LA-ICP-MS trace element analysis of Gs. ruber over a temperature range of 14.7-28.8°C. In contrast to the LA-ICP-MS study of Gs. ruber, the planktonic species N. incompta shows no systematic difference in Mg/Ca between the final four visible chambers at one core top site, nor between the F-3 and F chambers at any sites. In addition, there was no correlation between Mg/Ca ratios and ocean temperature in either reticulate or crystalline forms. This may reflect migration of this species within the water column that is not uni-directional, that this species does not dwell at the same depths at each core top site, or point towards further unidentified controls on Mg incorporation into N. incompta that require further study. The chamber specific calibrations developed for Gs. ruber in this study, and a calibration developed using the same techniques for G. bulloides [Marr et al., 2011] were applied down core to Mg/Ca ratios measured from ODP Site 1123. The SST derived from Mg/Ca ratios reveal that during the MIS-31 interglacial, SSTs were approximately 4-5°C warmer than today and 8-9°C warmer than those from MIS-29 and 30. A comparison of SSTs measured from Gs. ruber and G. bulloides, suggests that they are responding to local insolation changes. G. bulloides records colder temperatures than Gs. ruber, which reflects differences in their relative depth in the water column. Paired Mg/Ca and δ 18O data reveal significant changes in ice volume over the sampling period. Increases in SSTs recorded by the planktonic foraminifera lead the seawater stable isotope record by 10 kyr suggesting a significant influence from changes in Northern Hemisphere ice sheet volume during MIS-31. In some intervals, the SST leads the benthic stable isotope record by 8 kyr and shows deviations in benthic δ18O from synchronous planktic samples.</b></p> <p>In G. bulloides and Gs. ruber, Mn and Mg were the only trace elements to show systematic glacial-interglacial changes from MIS-34 to MIS-29. This correlation could imply that Mn/Ca ratios in the foraminifera are recording changes in ocean chemistry related to changing water mass circulation at ODP Site 1123 as past ocean temperatures changed. Size-normalised weights (SNW) of G. bulloides tests show systematic variations from MIS- 34 to MIS-29. For much of the record, SNW is anti-correlated with SST in a manner similar to the modern relationship between SNW and SST in the Southwest Pacific Ocean. However, immediately prior to the MIS-31 Southern Hemisphere insolation maxima, SNW increase with SST suggesting a fundamental change in surface ocean carbonate chemistry occurred that is unique to this time.</p>

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