A multiproxy approach to reconstruct the environmental changes along the Eurasian continental margin over the last 150 000 years

Knies, Jochen; Nowaczyk, Norbert R; Müller, Claudia; Vogt, Christoph; Stein, Rüdiger

doi:10.1016/s0025-3227(99)00106-1

Cited by 101 publications

(90 citation statements)

References 110 publications

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“…This conceptual model, in which Atlantic water inflow persists, perhaps episodically, during glacial periods but is restricted to the Eurasian Basin is in agreement with evidence for Atlantic water inflow to the Norwegian-Greenland Sea and through the Fram Strait reported at 145, 165 and 180 ka (Hebbeln and Wefer, 1997;Lloyd et al, 1996). Furthermore, interpretations based on the occurrence of warm-water dinoflagellate cysts, benthic foraminifera and the abundance of biogenic calcite, indicate penetration of warm Atlantic waters to the northern Barents Sea margin, at least to the Franz Victoria Trough, during the later part of MIS 6, MIS 3 and MIS 2 (Knies et al, 2000;Knies and Stein, 1999;Matthiessen and Knies, 2001). There is no indication of Atlantic water influence during MIS 6 in cores from the shelf off Severnaya Zemlya, with warmer water suggested only during the Holocene and Stage 5.5 ).…”

Section: The Role Of the Atlantic Water Influx And The Arctic Ocean Csupporting

confidence: 88%

An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data

Nilsson

O’Regan

Backman

et al. 2010

Quaternary Science Reviews

119

118

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a b s t r a c tThe hypothesis of floating ice shelves covering the Arctic Ocean during glacial periods was developed in the 1970s. In its most extreme form, this theory involved a 1000 m thick continuous ice shelf covering the Arctic Ocean during Quaternary glacial maxima including the Last Glacial Maximum (LGM). While recent observations clearly demonstrate deep ice grounding events in the central Arctic Ocean, the ice shelf hypothesis has been difficult to evaluate due to a lack of information from key areas with severe sea ice conditions. Here we present new data from previously inaccessible, unmapped areas that constrain the spatial extent and timing of marine ice sheets during past glacials. These data include multibeam swath bathymetry and subbottom profiles portraying glaciogenic features on the Chukchi Borderland, southern Lomonosov Ridge north of Greenland, Morris Jesup Rise, and Yermak Plateau. Sediment cores from the mapped areas provide age constraints on the glaciogenic features. Combining these new geophysical and geological data with earlier results suggests that an especially extensive marine ice sheet complex, including an ice shelf, existed in the Amerasian Arctic Ocean during Marine Isotope Stage (MIS) 6. From a conceptual oceanographic model we speculate that the cold halocline of the Polar Surface Water may have extended to deeper water depths during MIS 6 inhibiting the warm Atlantic water from reaching the Amerasian Arctic Ocean and, thus, creating favorable conditions for ice shelf development. The hypothesis of a continuous 1000 m thick ice shelf is rejected because our mapping results show that several areas in the central Arctic Ocean substantially shallower than 1000 m water depth are free from glacial influence on the seafloor.

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Section: The Role Of the Atlantic Water Influx And The Arctic Ocean Csupporting

confidence: 88%

An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data

Nilsson

O’Regan

Backman

et al. 2010

Quaternary Science Reviews

119

118

View full text Add to dashboard Cite

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“…For example, pore-water d sw measurements are different in the deep Pacific, and northern and southern Atlantic between the LGM and today ; the inferred changes suggest a large freshwater imbalance in the northern convecting regions during the LGM, with an important role for increased sea-ice formation and export. Given the great difference in Arctic sea-ice conditions that has been inferred between the PGM (less extensive and seasonally open) and LGM (extensive and severe sea-ice conditions) (Knies et al, 2000;Polyak et al, 2010;de Vernal et al, 2013;Niessen et al, 2013;Arndt et al, 2014;Jakobsson et al, 2010Jakobsson et al, , 2014bL€ owemark et al, 2016), a difference in both the isotopic composition and volumetric contribution of northern-sourced deep waters might be expected between the two glacial periods. There are some hints of local d sw differences between the two glacial intervals (e.g., Skinner and Shackleton, 2005), with a shoaled hydrographic gradient separating northern-and southern-sourced deep waters and a potentially weaker North Atlantic overturning cell during the PGM.…”

Section: The Global D 18 O:sea-level/ice-volume Relationshipmentioning

confidence: 99%

“…Such open waters may have provided an important moisture source for ice growth in Eurasia (Spielhagen et al, 2004). In order to reconcile the presence of a large ice shelf with continued warm-water advection into the Arctic (Lloyd et al, 1996;Knies et al, 2000;Spielhagen et al, 2004), deepening of the cold halocline and advection of Atlantic waters at greater depth than present have been proposed (e.g., Jakobsson et al, 2010;Cronin et al, 2012). The Lomonosov Ridge may have acted as a topographic barrier to Atlantic water circulation in the Amerasian Basin, possibly promoting ice-shelf growth in this region .…”

Section: The Global D 18 O:sea-level/ice-volume Relationshipmentioning

confidence: 99%

Differences between the last two glacial maxima and implications for ice-sheet, δ18O, and sea-level reconstructions

Rohling

Hibbert

Williams

et al. 2017

Quaternary Science Reviews

100

115

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Arctic ice shelf Last Interglacial Glacioisostatic adjustment a b s t r a c t Studies of past glacial cycles yield critical information about climate and sea-level (ice-volume) variability, including the sensitivity of climate to radiative change, and impacts of crustal rebound on sealevel reconstructions for past interglacials. Here we identify significant differences between the last and penultimate glacial maxima (LGM and PGM) in terms of global volume and distribution of land ice, despite similar temperatures and radiative forcing. Our analysis challenges conventional views of relationships between global ice volume, sea level, seawater oxygen isotope values, and deep-sea temperature, and supports the potential presence of large floating Arctic ice shelves during the PGM. The existence of different glacial 'modes' calls for focussed research on the complex processes behind ice-age development. We present a glacioisostatic assessment to demonstrate how a different PGM ice-sheet configuration might affect sea-level estimates for the last interglacial. Results suggest that this may alter existing last interglacial sea-level estimates, which often use an LGM-like ice configuration, by several metres (likely upward).

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“…2a). (Lisiecki and Raymo, 2005), and (h) the extent of Eurasian ice sheets between the coast and the shelf break (Knies et al, 1999(Knies et al, , 2000Müller et al, 1999). In the columnar section of PC 1 (panel a), the large black dots represent IRD clasts, the small black dots are scattered IRD and vertical black lines indicate laminated horizons based on visual core inspection and soft-X ray radiographs.…”

Section: Core Location and Descriptionmentioning

confidence: 99%

Sedimentary organic matter and carbonate variations in the Chukchi Borderland in association with ice sheet and ocean-atmosphere dynamics over the last 155 kyr

Rella

Uchida

2011

Biogeosciences

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Abstract. Knowledge on past variability of sedimentary organic carbon in the Arctic Ocean is important to assess natural carbon cycling and transport processes related to global climate changes. However, the late Pleistocene oceanographic history of the Arctic is still poorly understood. In the present study we show sedimentary records of total organic carbon (TOC), CaCO 3 , benthic foraminiferal δ 18 O and the coarse grain size fraction from a piston core recovered from the northern Northwind Ridge in the far western Arctic Ocean, a region potentially sensitively responding to past variability in surface current regimes and sedimentary processes such as coastal erosion. An age model based on oxygen stratigraphy, radiocarbon dating and lithological constraints suggests that the piston core records paleoenvironmental changes of the last 155 kyr. TOC shows orbital-scale increases and decreases that can be respectively correlated to the waxing and waning of large ice sheets dominating the Eurasian Arctic, suggesting advection of fine suspended matter derived from glacial erosion to the Northwind Ridge by eastward flowing intermediate water and/or surface water and sea ice during cold episodes of the last two glacialinterglacial cycles. At millennial scales, increases in TOC might correlate to a suite of Dansgaard-Oeschger Stadials between 120 and 45 ka before present (BP) indicating a possible response to abrupt northern hemispheric temperature changes. Between 70 and 45 ka BP, closures and openings of the Bering Strait could have additionally influenced TOC variability. CaCO 3 content tends to anti-correlate with TOC on both orbital and millennial time scales, which we interpret in terms of enhanced sediment advection from the carbonaterich Canadian Arctic via an extended Beaufort Gyre during warm periods of the last two glacial-interglacial cycles and increased organic carbon advection from the Siberian Arctic Correspondence to: M. Uchida (uchidama@nies.go.jp) during cold periods when the Beaufort Gyre contracted. We propose that this pattern may be related to orbital-and millennial-scale variations of dominant atmospheric surface pressure systems expressed in mode shifts of the Arctic Oscillation.

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A multiproxy approach to reconstruct the environmental changes along the Eurasian continental margin over the last 150 000 years

Cited by 101 publications

References 110 publications

An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data

An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data

Differences between the last two glacial maxima and implications for ice-sheet, δ18O, and sea-level reconstructions

Sedimentary organic matter and carbonate variations in the Chukchi Borderland in association with ice sheet and ocean-atmosphere dynamics over the last 155 kyr

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