Sea surface temperatures in the North Atlantic Ocean from 30ka to 10ka

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http://meetingorganizer.copernicus.org/EGU2016/EGU2016-1121.pdf
Author(s): Barrack, Kerr; Greenop, Rosanna; Burke, Andrea; Barker, Stephen; Chalk, Thomas; Crocker, Anya
Author Affiliation(s): Primary:
University of Saint Andrews, Department of Earth and Envrionmental Science, Saint Andrews, United Kingdom
Other:
Cardiff University, United Kingdom
Woods Hole Oceanographic Institution, United States
University of Southampton, United Kingdom
Volume Title: European Geosciences Union general assembly 2016
Source: Geophysical Research Abstracts, Vol.18; European Geosciences Union general assembly 2016, Vienna, Austria, April 17-22, 2016. Publisher: Copernicus GmbH on behalf of the European Geosciences Union (EGU), Katlenburg-Lindau, Germany. ISSN: 1029-7006
Note: In English. 3 refs.
Summary: Some of the most striking features of the late Pleistocene interval are the rapid changes in climate between warmer interstadial and cold stadial periods which, when coupled, are termed Dansgaard-Oeschger (D-O) events. This shift between warm and cold climates has been interpreted to result from changes in the thermohaline circulation (Broecker et al., 1985) triggered by, for instance, freshwater input from the collapse of the Laurentide ice sheet (Zahn et al., 1997). However, a recent study suggests that major ice rafting events cannot be the "trigger" for the centennial to millennial scale cooling events identified over the past 500kyr (Barker at al., 2015). Polar planktic foraminiferal and lithogenic/terrigenous grain counts reveal that the southward migration of the polar front occurs before the deposition of ice rafted debris and therefore the rafting of ice during stadial periods. Based upon this evidence, Barker et al. suggest that the transition to a stadial state is a non-linear response to gradual cooling in the region. In order to test this hypothesis, our study reconstructs sea surface temperature across D-O events and the deglaciation in the North Atlantic between 30ka and 10ka using Mg/Ca paleothermometry in Globigerina bulloides at ODP Sites 980 and 983 (the same sites as used in Barker et al., 2015) with an average sampling resolution of 300 years. With our new record we evaluate the timing of surface ocean temperature change, frontal shift movement, and ice rafting to investigate variations in the temperature gradient across the polar front over D-O events. References: Barker, S., Chen, J., Gong, X., Jonkers, L., Knorr, G., Thornalley, D., 2015. Icebergs not the trigger for North Atlantic cold events. Nature, 520(7547), p. 333-336. Broecker, W. S., Peteer, D. M., Rind, D., 1985. Does the ocean-atmosphere system have more than one stable mode of operation? Nature, 315 (6014), p. 21-26. Zahn, R., Schönfeld, J., Kudrass, H. R., Park, M. H., Erlenkeuser, H., Grootes, P., 1997. Thermohaline instability in the North Atlantic during meltwater events: Stable isotope and ice-rafted detritus records from Core SO75-26KL, Portuguese Margin. Paleoceanography, 12(5), p. 696-710. [Copyright Author(s) 2016. CC Attribution 3.0 License: https://creativecommons.org/licenses/by/3.0/legalcode]
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Alkaline earth metals; Atlantic Ocean; Biostratigraphy; Calcium; Cenozoic; Chemostratigraphy; Cores; Dansgaard-Oeschger cycles; Foraminifera; Leg 162; Magnesium; Marine sediments; Metals; Mg/Ca; Microfossils; North Atlantic; ODP Site 980; ODP Site 983; Ocean Drilling Program; Paleo-oceanography; Paleoclimatology; Paleotemperature; Quaternary; Reconstruction; Reykjanes Ridge; Rockall Bank; Sea-surface temperature; Sediments; Upper Quaternary
Coordinates: N552906 N552906 W0144208 W0144208
N602412 N602412 W0233826 W0233826
Record ID: 2019065029
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from European Geosciences Union, Munich, Germany