Changes of the upper water column at the 45°N North Atlantic since marine isotope stage 3

YE Xiaoxian; Harunur Rashid

doi:10.16562/j.cnki.0256-1492.2020073102

Marine Geology & Quaternary Geology > 2021 > 41(3): 114-123. > DOI: 10.16562/j.cnki.0256-1492.2020073102

YE Xiaoxian, Harunur Rashid. Changes of the upper water column at the 45°N North Atlantic since marine isotope stage 3[J]. Marine Geology & Quaternary Geology, 2021, 41(3): 114-123. DOI: 10.16562/j.cnki.0256-1492.2020073102

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Changes of the upper water column at the 45°N North Atlantic since marine isotope stage 3

YE Xiaoxian,
Harunur Rashid^,

College of Marine Sciences, Shanghai Ocean University, Shanghai, CHINA 201306

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Received Date: July 30, 2020
Revised Date: January 02, 2021
Available Online: June 14, 2021

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Abstract

Abstract

The 45°N of North Atlantic is located at the central zone of the ice-rafted detritus (IRD) belt of the North Atlantic, where the marine sediments contain rich environmental and climatic information of high-resolution. The sedimentary records there are used for reconstruction of the pale-oceanic environment since the last glacial in this study. IRD contents, planktonic foraminiferal assemblages and their oxygen and carbon isotopes (δ¹⁸O and δ¹³C) from the core Hu71-377, are used as major tools. Combined with AMS¹⁴C dating and oxygen isotope stratigraphy, five Heinrich layers are identified in the MIS3 and MIS2, in which the Heinrich layer 1, 2 and 4 have obvious IRD peaks, high relative abundance of Neogloboquadrina pachyderma and light δ¹⁸O values, but no obvious light δ¹⁸O are observed in the Heinrich layer 3 and 5. The difference in δ¹⁸O between the Heinrich layers 3 and 5 and the Heinrich layers 1, 2 and 4 may suggest the impacts of melt water on the upper water column. Further, the offsets between δ¹³C_N.incompta and δ¹³C_N.pachyderma may also reflect the changes in the mixed layer and thermocline during the Heinrich events. The δ¹³C offsets were close to zero during Heinrich 1 and Heinrich 2, attributing to the vertical mixing of seawater driven by strong winds. And the δ¹³C offsets became larger during Heinrich 4 and Heinrich 5, indicating that the seasonal thermocline became shallower, which supports the inference of the penetration of the North Atlantic Current. What’s more, the planktonic foraminiferal assemblages may reflect the properties of the water masses in the upper water column, especially the relative abundance of N. pachyderma and Neogloboquadrina incompta may indicate the sea surface temperature (SST) changes during MIS3.
- Heinrich events,
- planktonic foraminifera assemblages,
- carbon and oxygen isotopes,
- upper water masses variations,
- North Atlantic

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[1]	Lozier M S, Li F, Bacon S, et al. A sea change in our view of overturning in the subpolar North Atlantic [J]. Science, 2019, 363(6426): 516-521. doi: 10.1126/science.aau6592
[2]	Cléroux C, Cortijo E, Anand P, et al. Mg/Ca and Sr/Ca ratios in planktonic foraminifera: Proxies for upper water column temperature reconstruction [J]. Paleoceanography and Paleoclimatology, 2008, 23(3): PA3214.
[3]	Holliday N P, Bersch M, Berx B, et al. Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic [J]. Nature Communications, 2020, 11: 585. doi: 10.1038/s41467-020-14474-y
[4]	Bagniewski W, Meissner K J, Menviel L. Exploring the oxygen isotope fingerprint of Dansgaard-Oeschger variability and Heinrich events [J]. Quaternary Science Reviews, 2017, 159: 1-14. doi: 10.1016/j.quascirev.2017.01.007
[5]	Zhang X, Prange M. Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability [J]. Quaternary Science Reviews, 2020, 242: 106443. doi: 10.1016/j.quascirev.2020.106443
[6]	Dansgaard W, Johnsen S J, Clausen H B, et al. Evidence for general instability of past climate from a 250-kyr ice-core record [J]. Nature, 1993, 364(6434): 218-220. doi: 10.1038/364218a0
[7]	Rasmussen S O, Bigler M, Blockley S P, et al. A stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy [J]. Quaternary Science Reviews, 2014, 106: 14-28. doi: 10.1016/j.quascirev.2014.09.007
[8]	Bond G C, Heinrich H, Broecker W S, et al. Evidence for massive discharges of icebergs into the North Atlantic Ocean during the last glacial period [J]. Nature, 1992, 360(6401): 245-249. doi: 10.1038/360245a0
[9]	Voelker A H L. Global distribution of centennial-scale records for Marine Isotope Stage (MIS) 3: a database [J]. Quaternary Science Reviews, 2002, 21(10): 1185-1212. doi: 10.1016/S0277-3791(01)00139-1
[10]	Heinrich H. Origin and consequences of cyclic ice rafting in the northeast Atlantic Ocean during the past 130, 000 years [J]. Quaternary Research, 1988, 29(2): 142-152. doi: 10.1016/0033-5894(88)90057-9
[11]	Hemming S R. Heinrich events: Massive late Pleistocene detritus layers of the North Atlantic and their global climate imprint [J]. Reviews of Geophysics, 2004, 42(1): RG1005.
[12]	Broecker W. Massive iceberg discharges as triggers for global climate change [J]. Nature, 1994, 372(6505): 421-424. doi: 10.1038/372421a0
[13]	Guo C C, Nisancioglu K H, Bentsen M, et al. Equilibrium simulations of Marine Isotope Stage 3 climate [J]. Climate of the Past, 2019, 15(3): 1133-1151. doi: 10.5194/cp-15-1133-2019
[14]	Tolderlund D S, Be A W H. Seasonal distribution of planktonic foraminifera in the western North Atlantic [J]. Micropaleontology, 1971, 17(3): 297-329. doi: 10.2307/1485143
[15]	Schiebel R, Hemleben C. Classification and taxonomy of extant planktic foraminifers[C]//Planktic Foraminifers in the Modern Ocean. Berlin: Springer, 2017: 11-110.
[16]	McIntyre A, Kipp N G, Bé A W H, et al. Glacial North Atlantic 18, 000 years ago: A _CLIMAP reconstruction[M]//Cline R M, Hays D J. Investigation of Late Quaternary Paleoceanography and Paleoclimatology. Boulder, Colorado: Geological Society of America, 1976: 43-76.
[17]	CLIMAP Project Members. The surface of the ice-age earth [J]. Science, 1976, 191(4232): 1131-1137. doi: 10.1126/science.191.4232.1131
[18]	Ruddiman W F, McIntyre A. The mode and mechanism of the last deglaciation: Oceanic evidence [J]. Quaternary Research, 1981, 16(2): 125-134. doi: 10.1016/0033-5894(81)90040-5
[19]	Ruddiman W F, Raymo M E, Martinson D G, et al. Pleistocene evolution: northern hemisphere ice sheets and North Atlantic Ocean [J]. Paleoceanography and Paleoclimatology, 1989, 4(4): 353-412.
[20]	Pflaumann U, Duprat J, Pujol C, et al. SIMMAX: A modern analog technique to deduce Atlantic sea surface temperatures from planktonic foraminifera in deep-sea sediments [J]. Paleoceanography and Paleoclimatology, 1996, 11(1): 15-35.
[21]	Sarnthein M, Pflaumann U, Weinelt M. Past extent of sea ice in the northern North Atlantic inferred from foraminiferal paleotemperature estimates [J]. Paleoceanography and Paleoclimatology, 2003, 18(2): 1047.
[22]	Rashid H, Boyle E A. Mixed-layer deepening during Heinrich events: a multi-planktonic foraminiferal δ¹⁸O approach [J]. Science, 2007, 318(5849): 439-441. doi: 10.1126/science.1146138
[23]	Rashid H, Boyle E A. Response to comment on “Mixed-layer deepening during Heinrich events: a multi-planktonic foraminiferal δ¹⁸O approach” [J]. Science, 2008, 320(5880): 1161.
[24]	Kohfeld K E, Fairbanks R G, Smith S L, et al. Neogloboquadrina pachyderma (sinistral coiling) as paleoceanographic tracers in polar oceans: evidence from northeast water polynya plankton tows, sediment traps, and surface sediments [J]. Paleoceanography and Paleoclimatology, 1996, 11(6): 679-699.
[25]	Brummer G J A, Metcalfe B, Feldmeijer W, et al. Modal shift in North Atlantic seasonality during the last deglaciation [J]. Climate of the Past, 2020, 16(1): 265-282. doi: 10.5194/cp-16-265-2020
[26]	Ruddiman W F. Late Quaternary deposition of ice-rafted sand in the subpolar North Atlantic (lat 40° to 65°N) [J]. GSA Bulletin, 1977, 88(12): 1813-1827. doi: 10.1130/0016-7606(1977)88<1813:LQDOIS>2.0.CO;2
[27]	Scott D B, Baki V, Younger C D, et al. Empirical method for measuring seasonality in deep-sea cores [J]. Geology, 1986, 14(8): 643-646. doi: 10.1130/0091-7613(1986)14<643:EMFMSI>2.0.CO;2
[28]	Grousset F E, Labeyrie L, Sinko J A, et al. Patterns of ice-rafted detritus in the glacial north Atlantic (40-55°N) [J]. Paleoceanography and Paleoclimatology, 1993, 8(2): 175-192.
[29]	Van Kreveld S, Sarnthein M, Erlenkeuser H, et al. Potential links between surging ice sheets, circulation changes, and the Dansgaard-Oeschger cycles in the Irminger Sea, 60-18 kyr [J]. Paleoceanography and Paleoclimatology, 2000, 15(4): 425-442.
[30]	Jonkers L, Moros M, Prins M A, et al. A reconstruction of sea surface warming in the northern North Atlantic during MIS 3 ice-rafting events [J]. Quaternary Science Reviews, 2010, 29(15-16): 1791-1800. doi: 10.1016/j.quascirev.2010.03.014
[31]	Chapman M R, Shackleton N J, Duplessy J C. Sea surface temperature variability during the last glacial-interglacial cycle: assessing the magnitude and pattern of climate change in the North Atlantic [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2000, 157(1-2): 1-25. doi: 10.1016/S0031-0182(99)00168-6
[32]	Rashid H, Piper D J W, Drapeau J, et al. Sedimentology and history of sediment sources to the NW Labrador Sea during the past glacial cycle [J]. Quaternary Science Reviews, 2019, 221: 105880. doi: 10.1016/j.quascirev.2019.105880
[33]	Lougheed B C, Obrochta S P. A rapid, deterministic age-depth modeling routine for geological sequences with inherent depth uncertainty [J]. Paleoceanography and Paleoclimatology, 2009, 34(1): 122-133.
[34]	Heaton T J, Köhler P, Butzin M, et al. Marine20-the marine radiocarbon age calibration curve (0-55,000 cal BP) [J]. Radiocarbon, 2020, 62(4): 779-820. doi: 10.1017/RDC.2020.68
[35]	Seierstad I K, Abbott P M, Bigler M, et al. Consistently dated records from the Greenland GRIP, GISP2 and NGRIP ice cores for the past 104 ka reveal regional millennial-scale δ¹⁸O gradients with possible Heinrich event imprint [J]. Quaternary Science Reviews, 2014, 106: 29-46. doi: 10.1016/j.quascirev.2014.10.032
[36]	Bond G, Broecker W, Johnsen S, et al. Correlations between climate records from North Atlantic sediments and Greenland ice [J]. Nature, 1993, 365(6442): 143-147. doi: 10.1038/365143a0
[37]	Obrochta S P, Miyahara H, Yokoyama Y, et al. A re-examination of evidence for the North Atlantic “1500-year cycle” at site 609 [J]. Quaternary Science Reviews, 2012, 55: 23-33. doi: 10.1016/j.quascirev.2012.08.008
[38]	Griem L, Voelker A H L, Berben S M P, et al. Insolation and glacial meltwater influence on sea-ice and circulation variability in the northeastern Labrador Sea during the last glacial period [J]. Paleoceanography and Paleoclimatology, 2019, 34(11): 1689-1709. doi: 10.1029/2019PA003605
[39]	Lisiecki L E, Stern J V. Regional and global benthic δ¹⁸O stacks for the last glacial cycle [J]. Paleoceanography and Paleoclimatology, 2016, 31(10): 1368-1394.
[40]	Came R E, Oppo D W, McManus J F. Amplitude and timing of temperature and salinity variability in the subpolar North Atlantic over the past 10 k.y. [J]. Geology, 2007, 35(4): 315-318. doi: 10.1130/G23455A.1
[41]	Clark P U, Dyke A S, Shakun J D, et al. The last glacial maximum [J]. Science, 2009, 325(5941): 710-714.
[42]	Cortijo E, Labeyrie L, Vidal L, et al. Changes in sea surface hydrology associated with Heinrich event 4 in the North Atlantic Ocean between 40° and 60°N [J]. Earth and Planetary Science Letters, 1997, 146(1-2): 29-45. doi: 10.1016/S0012-821X(96)00217-8
[43]	Bond G C, Lotti R. Iceberg discharges into the North Atlantic on millennial time scales during the last glaciation [J]. Science, 1995, 267(5200): 1005-1010. doi: 10.1126/science.267.5200.1005
[44]	Xiao W S, Wang R J, Polyak L, et al. Stable oxygen and carbon isotopes in planktonic foraminifera Neogloboquadrina pachyderma in the Arctic Ocean: an overview of published and new surface-sediment data [J]. Marine Geology, 2014, 352: 397-408. doi: 10.1016/j.margeo.2014.03.024
[45]	Missiaen L, Pichat S, Waelbroeck C, et al. Downcore variations of sedimentary detrital (²³⁸U/²³²Th) ratio: implications on the use of ²³⁰Th_xs and ²³¹Pa_xs to reconstruct sediment flux and ocean circulation [J]. Geochemistry, Geophysics, Geosystems, 2018, 19(8): 2560-2573. doi: 10.1029/2017GC007410
[46]	Govin A, Braconnot P, Capron E, et al. Persistent influence of ice sheet melting on high northern latitude climate during the early Last Interglacial [J]. Climate of the Past, 2012, 8(2): 483-507. doi: 10.5194/cp-8-483-2012
[47]	Zaric S, Donner B, Fischer G, et al. Sensitivity of planktic foraminifera to sea surface temperature and export production as derived from sediment trap data [J]. Marine Micropaleontology, 2005, 55(1-2): 75-105. doi: 10.1016/j.marmicro.2005.01.002
[48]	Ottens J J. Planktic foraminifera as North Atlantic water mass indicators [J]. Oceanologica Acta, 1991, 14(2): 123-140.
[49]	Morley A, Babila T L, Wright J, et al. Environmental controls on Mg/Ca in Neogloboquadrina incompta: A core-top study from the subpolar North Atlantic [J]. Geochemistry, Geophysics, Geosystems, 2017, 18(12): 4276-4298. doi: 10.1002/2017GC007111
[50]	Irvali N, Galaasen E V, Ninnemann U S, et al. A low climate threshold for south Greenland Ice Sheet demise during the Late Pleistocene [J]. Proceedings of the National Academy of Sciences of the United States of America, 2020, 117(1): 190-195. doi: 10.1073/pnas.1911902116
[51]	Villanueva J, Grimalt J O, Cortijo E, et al. Assessment of sea surface temperature variations in the central North Atlantic using the alkenone unsaturation index (U₃₇^k’) [J]. Geochimica et Cosmochimica Acta, 1998, 62(14): 2421-2427. doi: 10.1016/S0016-7037(98)00180-X
[52]	Madureira L A S, Van Kreveld S A, Eglinton G, et al. Late Quaternary high-resolution biomarker and other sedimentary climate proxies in a Northeast Atlantic Core [J]. Paleoceanography and Paleoclimatology, 1997, 12(2): 255-269.
[53]	Eynaud F, De Abreu L, Voelker A, et al. Position of the polar front along the western Iberian margin during key cold episodes of the last 45 ka [J]. Geochemistry, Geophysics, Geosystems, 2009, 10(7): Q07U05.
[54]	Marchitto T M, Curry W B, Lynch-Stieglitz J, et al. Improved oxygen isotope temperature calibrations for cosmopolitan benthic foraminifera [J]. Geochimica et Cosmochimica Acta, 2014, 130: 1-11. doi: 10.1016/j.gca.2013.12.034
[55]	Curry W B, Oppo D W. Glacial water mass geometry and the distribution of δ¹³C of ΣCO₂ in the western Atlantic ocean [J]. Paleoceanography and Paleoclimatology, 2005, 20(1): PA1017.
[56]	Keigwin L D, Boyle E A. Late quaternary paleochemistry of high-latitude surface waters [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1989, 73(1-2): 85-106. doi: 10.1016/0031-0182(89)90047-3
[57]	Mook W G, Bommerson J C, Staverman W H. Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide [J]. Earth and Planetary Science Letters, 1974, 22(2): 169-176. doi: 10.1016/0012-821X(74)90078-8
[58]	Zhan R, Winn K, Sarnthein M. Benthic foraminiferal δ¹³C and accumulation rates of organic carbon: Uvigerina Peregrina group and Cibicidoides Wuellerstorfi [J]. Paleoceanography and Paleoclimatology, 1986, 1(1): 27-42.
[59]	Lynch-Stieglitz J, Fairbanks R G, Charles C D. Glacial-interglacial history of Antarctic intermediate water: relative strengths of Antarctic versus Indian Ocean sources [J]. Paleoceanography and Paleoclimatology, 1994, 9(1): 7-29.
[60]	Polyak L, Curry W B, Darby D A, et al. Contrasting glacial/interglacial regimes in the western Arctic Ocean as exemplified by a sedimentary record from the Mendeleev Ridge [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2004, 203(1-2): 73-93. doi: 10.1016/S0031-0182(03)00661-8
[61]	李铁刚, 孙荣涛, 张德玉, 等. 晚第四纪对马暖流的演化和变动: 浮游有孔虫和氧碳同位素证据[J]. 中国科学 D辑: 地球科学, 2007, 50(5):725-735 doi: 10.1007/s11430-007-0003-2 LI Tiegang, SUN Rongtao, ZHANG Deyu, et al. Evolution and variation of the Tsushima warm current during the late quaternary: Evidence from planktonic foraminifera, oxygen and carbon isotopes [J]. Science in China Series D: Earth Sciences, 2007, 50(5): 725-735. doi: 10.1007/s11430-007-0003-2
[62]	Elderfield H, Vautravers M, Cooper M. The relationship between shell size and Mg/Ca, Sr/Ca, δ¹⁸O, and δ¹³C of species of planktonic foraminifera [J]. Geochemistry, Geophysics, Geosystems, 2002, 3(8): 1-13.
[63]	Donner B, Wefer G. Flux and stable isotope composition of Neogloboquadrina pachyderma and other planktonic foraminifers in the southern ocean (Atlantic sector) [J]. Deep Sea Research Part I: Oceanographic Research Papers, 1994, 41(11-12): 1733-1743. doi: 10.1016/0967-0637(94)90070-1

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Changes of the upper water column at the 45°N North Atlantic since marine isotope stage 3