Biotic response of benthic foraminifera to OMZ variations in the northwestern Pacific since the last deglaciation

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Keisuke Sakai ◽  
Ken’ichi Ohkushi ◽  
Akihiko Shibahara
Keyword(s):  
Benthic Foraminifera ◽  
Northwestern Pacific ◽  
Last Deglaciation ◽  
Biotic Response ◽  
The Last Deglaciation

Millennial-scale changes of surface and bottom water conditions in the northwestern Pacific during the last deglaciation

2017 ◽  
Vol 154 ◽  
pp. 33-43 ◽  
Author(s):  
Sunghan Kim ◽  
Boo-Keun Khim ◽  
Ken Ikehara ◽  
Takuya Itaki ◽  
Akihiko Shibahara ◽  
...  
Keyword(s):  
Bottom Water ◽  
Northwestern Pacific ◽  
Last Deglaciation ◽  
Water Conditions ◽  
The Last Deglaciation ◽  
Millennial Scale

scholarly journals North Indian Ocean Circulation Since the Last Deglaciation as Inferred From New Elemental Ratio Records for Benthic Foraminifera Hoeglundina elegans

2020 ◽  
Vol 35 (6) ◽  
Author(s):  
Ruifang Ma ◽  
Sophie Sépulcre ◽  
Franck Bassinot ◽  
Frédéric Haurine ◽  
Nadine Tisnérat‐Laborde ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Benthic Foraminifera ◽  
North Indian Ocean ◽  
Last Deglaciation ◽  
Elemental Ratio ◽  
The Last Deglaciation

scholarly journals Supplementary material to "Bottom-water deoxygenation at the Peruvian Margin during the last deglaciation recorded by benthic foraminifera"

2019 ◽  
Author(s):  
Zeynep Erdem ◽  
Joachim Schönfeld ◽  
Anthony E. Rathburn ◽  
Maria-Elena Pérez ◽  
Jorge Cardich ◽  
...  
Keyword(s):  
Benthic Foraminifera ◽  
Bottom Water ◽  
Last Deglaciation ◽  
Water Deoxygenation ◽  
Supplementary Material ◽  
The Last Deglaciation

Late Glacial to Holocene benthic foraminifera in the Marmara Sea: implications for Black Sea–Mediterranean Sea connections following the last deglaciation

2002 ◽  
Vol 190 (1-2) ◽  
pp. 165-202 ◽  
Author(s):  
Michael A. Kaminski ◽  
Ali Aksu ◽  
Matthew Box ◽  
Richard N. Hiscott ◽  
Sorin Filipescu ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Black Sea ◽  
Benthic Foraminifera ◽  
Late Glacial ◽  
Marmara Sea ◽  
Last Deglaciation ◽  
The Last Deglaciation

scholarly journals Extreme lowering of deglacial seawater radiocarbon content is recorded by both epifaunal and infaunal benthic foraminifera

2018 ◽  
Author(s):  
Patrick A. Rafter ◽  
Juan-Carlos Herguera ◽  
John R. Southon
Keyword(s):  
Carbon Cycling ◽  
Benthic Foraminifera ◽  
Atmospheric Co2 ◽  
Last Deglaciation ◽  
Northeast Pacific ◽  
Co2 Concentrations ◽  
Age Model ◽  
Major Disruption ◽  
The Last Deglaciation ◽  
Atmospheric Co2 Concentrations

Abstract. For over a decade, oceanographers have debated the interpretation and reliability of sediment microfossil records indicating extremely low seawater radiocarbon (14C) during the last deglaciation-observations that suggest a major disruption in marine carbon cycling coincident with rising atmospheric CO2 concentrations. Possible flaws in these records include poor age model controls, utilization of mixed, infaunal foraminifera species possibly influenced by changing porewater chemistry, and bioturbation. We have addressed these concerns using a glacial-interglacial record of epifaunal benthic foraminifera 14C on an ideal sedimentary age model (wood calibrated to atmosphere 14C). Our results affirm – with important caveats – the fidelity of these microfossil archives and confirm previous observations of highly depleted seawater 14C at intermediate depths in the deglacial northeast Pacific.

scholarly journals Radiocarbon Marine Reservoir Ages in the Northwestern Pacific Off Hokkaido Island, Japan, During the Last Deglacial Period

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 963-968 ◽  
Author(s):  
Ken'ichi Ohkushi ◽  
Masao Uchida ◽  
Kaori Aoki ◽  
Minoru Yoneda ◽  
Ken Ikehara ◽  
...  
Keyword(s):  
Deep Water ◽  
Sediment Cores ◽  
Water Reservoir ◽  
Northwestern Pacific ◽  
Last Deglaciation ◽  
Planktic Foraminifera ◽  
The Last Deglaciation ◽  
Hokkaido Island ◽  
Reservoir Age ◽  
Northern Japan

We measured radiocarbon ages of planktic foraminifera in 4 sediment cores from the northwestern Pacific region off northern Japan in order to estimate marine reservoir ages during the B⊘lling-Aller⊘d period. The ages of deglacial tephra markers from 2 Japanese source volcanoes identified in these sediment cores had been previously estimated from 14C ages of terrestrial charcoal and buried forests. By comparing the foraminiferal and tephra ages, we estimated the surface water reservoir age during the B⊘lling-Aller⊘d period to be ∼1000 yr or more in the region off northern Japan. The deglacial reservoir ages were more than 200 yr higher than the Holocene values of ∼800 yr. The older deglacial ages may have been caused by active upwelling of deep water during the last deglaciation and the consequent mixing of “older” deep water with “younger” surface waters.

scholarly journals Eastern Mediterranean Sea circulation inferred from the conditions of S1 sapropel deposition

2015 ◽  
Vol 11 (6) ◽  
pp. 855-867 ◽  
Author(s):  
K. Tachikawa ◽  
L. Vidal ◽  
M. Cornuault ◽  
M. Garcia ◽  
A. Pothin ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Benthic Foraminifera ◽  
Bottom Water ◽  
Eastern Mediterranean ◽  
Last Deglaciation ◽  
Short Term ◽  
Total Recovery ◽  
Eastern Mediterranean Sea ◽  
The Last Deglaciation ◽  
Freshwater Inputs

Abstract. Holocene eastern Mediterranean Sea sediments contain an organic-rich sapropel S1 layer that was formed in oxygen-depleted waters. The spatial distribution of this layer revealed that during S1 deposition, deep waters were anoxic below a depth of 1800 m. However, whether this boundary permanently existed from the early to the mid-Holocene has not been examined yet. To answer this question, a multi-proxy approach was applied to a core retrieved close to the 1800 m boundary (at 1780 m). We measured the bulk sediment elemental composition, the stable isotopic composition of the planktonic foraminifer Globigerinoides ruber and the abundance of benthic foraminifera since the last deglaciation. The result indicates that authigenic U and Mo accumulation began around 13–12 cal ka BP, in concert with surface water freshening estimated from the G. ruber δ18O record. The onset of bottom and pore water oxygen depletion occurred prior to S1 deposition inferred from barium enrichment. In the middle of the S1 deposition period, reduced authigenic V, Fe and As contents and the Br/Cl ratio indicated short-term bottom-water re-oxygenation. A sharp Mn peak and maximal abundance for benthic foraminifera marked a total recovery for circulation at approximately 7 cal ka BP. Based on our results and existing data, we suggest that S1 formation within the upper 1780 m of the eastern Mediterranean Sea was preconditioned by reduced ventilation, resulting from excess freshwater inputs due to insolation changes under deglacial conditions that initiated between 15 and 12 cal ka BP within the upper 1780 m. Short-term re-oxygenation in the Levantine Basin is estimated to have affected bottom water at least as deep as 1780 m in response to cooling and/or the reduction of freshwater inputs. We tentatively propose that complete ventilation recovery at the S1 termination was depth-dependent, with earlier oxygenation within the upper 1780 m. Our results provide new constraints on vertical water column structure in the eastern Mediterranean Sea since the last deglaciation.

scholarly journals Extreme lowering of deglacial seawater radiocarbon recorded by both epifaunal and infaunal benthic foraminifera in a wood-dated sediment core

2018 ◽  
Vol 14 (12) ◽  
pp. 1977-1989 ◽  
Author(s):  
Patrick A. Rafter ◽  
Juan-Carlos Herguera ◽  
John R. Southon
Keyword(s):  
Carbon Cycling ◽  
Sediment Core ◽  
Benthic Foraminifera ◽  
Atmospheric Co2 ◽  
Last Deglaciation ◽  
Northeast Pacific ◽  
Age Model ◽  
Major Disruption ◽  
The Last Deglaciation ◽  
Atmospheric Co2 Concentrations

Abstract. For over a decade, oceanographers have debated the interpretation and reliability of sediment microfossil records indicating extremely low seawater radiocarbon (14C) during the last deglaciation – observations that suggest a major disruption in marine carbon cycling coincident with rising atmospheric CO2 concentrations. Possible flaws in these records include poor age model controls, utilization of mixed infaunal foraminifera species, and bioturbation. We have addressed these concerns using a glacial–interglacial record of epifaunal benthic foraminifera 14C on an ideal sedimentary age model (wood calibrated to atmosphere 14C). Our results affirm – with important caveats – the fidelity of these microfossil archives and confirm previous observations of highly depleted seawater 14C at intermediate depths in the deglacial northeast Pacific.

Sign in / Sign up

Export Citation Format

Share Document