An ocean–ice coupled response during the last glacial: a view from a marine isotopic stage 3 record south of the Faeroe Shetland Gateway

Abstract

Abstract. The rapid climatic variability characterising the Marine Isotopic Stage (MIS) 3 (∼ 60-30 cal ka BP) provides key issues to understand the atmosphere-ocean-cryosphere dynamics. Here we investigate the response of sea-surface paleoenvironments to the MIS3 climatic variability through the study of a high resolution oceanic sedimentological archive (core MD99-2281, 60 • 21 N; 09 • 27 W; 1197 m water depth), retrieved during the MD114-IMAGES (International Marine Global Change Study) cruise from the southern part of the Faeroe Bank. This sector was under the proximal influence of European ice sheets (Fennoscandian Ice Sheet to the East, British Irish Ice Sheet to the South) during the last glacial and thus probably responded to the MIS3 pulsed climatic changes.We conducted a multi-proxy analysis of core MD99-2281, including magnetic properties, x-ray fluorescence measurements, characterisation of the coarse (> 150 µm) lithic fraction (grain concentration) and the analysis of selected biogenic proxies (assemblages and stable isotope ratio of calcareous planktonic foraminifera, dinoflagellate cyst -e.g. dinocyst -assemblages). Results presented here are focussed on the dinocyst response, this proxy providing the reconstruction of past sea-surface hydrological conditions, qualitatively as well as quantitatively (e.g. transfer function sensu lato). Our study documents a very coherent and sensitive oceanic response to the MIS3 rapid climatic variability: strong fluctuations, matching those of stadial/interstadial climatic oscillations as depicted by Greenland ice cores, are recorded in the MD99-2281 archive. Proxies of terrigeneous and detritical material suggest increases in continental advection during Greenland Stadials (including Heinrich events), the latter corresponding also to southward migrations of polar waters. At the opposite, milder sea-surface conditions seem to develop during Greenland Interstadials. After 30 ka, reconstructed paleohydrological conditions evidence strong shifts in SST: this increasing variability seems consistent with the hypothesised coalescence of the British and Fennoscandian ice sheets at that time, which could have directly influenced sea-surface environments in the vicinity of core MD99-2281.

Evidence for a three-phase sequence during Heinrich Stadial 4 using a multiproxy approach based on Greenland ice core records

“…Other palaeoclimate archives show the same insensitivity, e.g. no specific sea ice change is depicted during the entire stadial 9 as inferred from deep sea core records obtained from the Irminger Sea and south of the Faroe Islands (Cortijo et al, 2005;Zumaque et al, 2012).…”

The southern Norwegian Sea during the last 45 ka: hydrographical reorganizations under changing ice‐sheet dynamics

“…(2012; revised age model using Calib7.1 and linear interpolation between original tie‐points). (e) Relative palaeointensity (RPI) signals from nearby cores MD95‐2009 (Kissel et al ., ) and MD99‐2281 (Zumaque et al ., ), and from stack GLOPIS‐75 (Laj et al ., ), showing two climate‐independent stratigraphic control points, namely the Mono Lake and Laschamp excursions (blue vertical bands).…”

“…Fig. 1c) low field susceptibility k signal from Kissel et al (1999; (Kissel et al, 1999) and MD99-2281 (Zumaque et al, 2012), and from stack GLOPIS-75 (Laj et al, 2004), showing two climate-independent stratigraphic control points, namely the Mono Lake and Laschamp excursions (blue vertical bands). glacial/deglaciation.…”

Regional seesaw between the North Atlantic and Nordic Seas during the last glacial abrupt climate events

“…To complement our view of the system, we also compare our sea-surface hydrographical reconstructions with (i) the relative abundance of the mesopelagic polar planktonic foraminifera NPS obtained in the same cores (Eynaud et al, 2002;Zumaque et al, 2012;Wary, 2015) and considered as tracer of cold subsurface conditions (see Supplement Sects. S5 and S6 for further details; Carstens and Wefer, 1992;Bauch et al, 1997;Carstens et al, 1997;Hillaire-Marcel and Bilodeau, 2000;Volkmann and Mensch, 2001;Simstich et al, 2003;Hillaire-Marcel et al, 2004;Kretschmer et al, 2016), and (ii) Greenland ice core deuterium excess data as indicator of Greenland moisture origin (Masson-Delmotte et al, 2005).…”

“…S1, Fig. S1, and Table S2 in the Supplement; Martinson et al, 1987;Manthé, 1998;Laj et al, 2004;Rasmussen et al, 2006;Zumaque et al, 2012;Caulle et al, 2013;Reimer et al, 2013;Wolff et al, 2010;Wary et al, 2016).…”