Simon, Margit H; Rutledal, Sunniva; Menviel, Laurie; Zolles, Tobias; Haflidason, Haflidi; Born, Andreas; Berben, Sarah M P; Dokken, Trond: Atlantic inflow into the southern Nordic Seas at the onset of the LGM promotes open-ocean conditions and Fennoscandian Ice Sheet growth [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.964056 (dataset in review)
Abstract:
Tephra analysis (FMAZ II-1 tephra marker) on a network of ten marine sediment cores in the northern North Atlantic is presented as well as radiocarbon dates (14C) by Accelerator Mass Spectrometry (AMS) of the same layers. We use published data for the Tephra horizon's identified in the cores together with eight already published 14C AMS dates. In two out of the ten cores we newly 14C AMS date. Here, we add radiocarbon dates to the existing ones from the FMAZ II-1 tephra layer from two key sites in the high-latitude North Atlantic Ocean: offshore southeast Greenland (GS16-204-18CC) and the southern Norwegian Sea (MD99-2284). The purpose of radiocarbon dating the volcanic ash layers in the marine sediments is to derive marine 14C reservoir ages (MRAs) from a spatial network of ten marine sediment cores for investigating past changes in the North Atlantic surface ocean circulation.
For the near-surface MRA reconstruction, approximately 1.5 mg of planktic foraminifera specimens (150-500 µm) in pristine condition were picked from the same depth level as the identified FMAZ II-1 tephra marker. The samples were then radiocarbon-dated using AMS 14C measurement procedures at ETH Zürich, Switzerland. There, the samples were processed using a newly developed method (Wacker et al., 2013) involving direct CO2 measurements of ~ 0.5 mg using an AMS facility equipped with a gas ion source. In addition, we performed leaching experiments on the sample surface material using HCl 0.02 M, following procedures in ref. (Hajdas et al., 2004). The AMS 14C dates from all sites were measured on the near-surface planktonic species Neogloboquadrina pachyderma (N. pachyderma) (calcification depth ∼30-200 m (Greco et al., 2019; Simstich et al., 2003)) permitting reconstruction of near-surface water mass properties.
We calculated the near-surface MRAs (in 14C years) as the difference between the measured planktonic (N. pachyderma) 14C age and the IntCal20 atmospheric 14C calibration curve (Reimer et al., 2020). The uncertainty of the reconstructed MRAs is calculated by combining the uncertainty (summation in quadrature method) related to (1) 14C analytical error, (2) GICC05 ice core age model error for FMAZ II-1 age, (3) IntCal20 calibration curve, and (4) transfer-function related to IntCal20 and GICC05 age offset (Adolphi et al., 2018). For two of the marine sediment cores, the AMS 14C date was not extracted from the exact same core depth as the FMAZ II-1 tephra layer. For sediment core LINK04, the spacing between the AMS 14C date and the position of the FMAZ II-1 tephra layer is 12 cm. Therefore, the AMS 14C date was adjusted using the correction originally provided by Wastegård et al. (2006).
Supplement to:
Simon, Margit H; Rutledal, Sunniva; Menviel, Laurie; Zolles, Tobias; Haflidason, Haflidi; Born, Andreas; Berben, Sarah M P; Dokken, Trond: Atlantic inflow into the southern Nordic Seas at the onset of the LGM promotes open-ocean conditions and Fennoscandian Ice Sheet growth. Communications Earth & Environment
Related to:
Bäckström, Denise L (2001): Late Quarternay North Atlantic paleoceanographic records and stable isotope variability in four planktonic foraminiferal species. Journal of Foraminiferal Research, 31(1), 25-32, https://doi.org/10.2113/0310025
Becker, Lukas W M; Sejrup, Hans Petter; Hjelstuen, Berit O; Haflidason, Haflidi; Dokken, Trond (2018): Ocean-ice sheet interaction along the SE Nordic Seas margin from 35 to 15 ka BP. Marine Geology, 402, 99-117, https://doi.org/10.1016/j.margeo.2017.09.003
Hoff, Ulrike; Rasmussen, Tine Lander; Stein, Ruediger; Ezat, Mohamed M; Fahl, Kirsten (2016): Sea ice and millennial-scale climate variability in the Nordic seas 90 ka to present. Nature Communications, 7, 10 pp, https://doi.org/10.1038/ncomms12247
Rasmussen, Tine Lander; Thomsen, Erik; van Weering, Tjeerd C E (1998): Cyclic sedimentation on the Faeroe Drift 53-10 ka BP related to climatic variations. In: Stoker, MS; Evans, D; Cramp, A (eds), Geological Processes on Continental Margins: Sedimentation, Mass-Wasting and Stability, Geology Society, London, Special Publications, 129, 255-267
Rasmussen, Tine Lander; Wastegård, Stefan; Kuijpers, Antoon; van Weering, Tjeerd C E; Heinemeier, Jan; Thomsen, Erik (2003): Stratigraphy and distribution of tephra layers in marine sediment cores from the Faeroe Islands, North Atlantic. Marine Geology, 199(3-4), 263-277, https://doi.org/10.1016/S0025-3227(03)00219-6
Wastegård, Stefan; Rasmussen, Tine Lander; Kuijpers, Antoon; Nielsen, Tove; van Weering, Tjeerd C E (2006): Composition and origin of ash zones from Marine Isotope Stages 3 and 2 in the North Atlantic. Quaternary Science Reviews, 25(17-18), 2409-2419, https://doi.org/10.1016/j.quascirev.2006.03.001
Funding:
European Research Council (ERC), grant/award no. 610055: Arctic Sea Ice and Greenland Ice Sheet Sensitivity
Coverage:
Median Latitude: 61.860012 * Median Longitude: -7.623105 * South-bound Latitude: 60.030667 * West-bound Longitude: -40.557500 * North-bound Latitude: 64.656500 * East-bound Longitude: 4.209500
Date/Time Start: 1999-08-01T00:00:00 * Date/Time End: 2018-08-21T00:00:00
Minimum Elevation: -2200.0 m * Maximum Elevation: -770.0 m
Event(s):
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Simon, Margit H | |||
| 2 | Age, dated | Age dated | ka | Simon, Margit H | Age, 14C AMS | uncorrected |
| 3 | Age, dated standard error | Age std e | ± | Simon, Margit H | uncorrected | |
| 4 | Age, dated | Age dated | ka | Simon, Margit H | Age, 14C calibrated | corrected |
| 5 | Age, dated standard error | Age std e | ± | Simon, Margit H | corrected | |
| 6 | Reservoir age | Res age | ka | Simon, Margit H | Marine Reservoir age transfer-function (Adolphi et al. 2018) | |
| 7 | Reservoir age, standard error | Res age e | ± | Simon, Margit H | ||
| 8 | Reference/source | Reference | Simon, Margit H | for radiocarbon dates |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Size:
52 data points