Asynchronous instability of the North American-Arctic and Greenland ice sheets during the last deglaciation

Jackson, Rebecca; Carlson, Anders E.; Hillaire‐Marcel, Claude; Wacker, Lukas; Vogt, Christoph; Kučera, Michal

doi:10.1016/j.quascirev.2017.03.020

Cited by 42 publications

(34 citation statements)

References 88 publications

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“…L4b extends to the surface sediments in Smith Sound and must reflect establishment of modern conditions including the NOW. However, the data herein do not indicate conclusively when the NOW formed Jackson et al 2017;Jennings et al 2017a…”

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confidence: 88%

Retreat of the Smith Sound Ice Stream in the Early Holocene

Jennings

Andrews

Oliver

et al. 2019

Boreas

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Nares Strait, a major connection between the Arctic Ocean and Baffin Bay, was blocked by coalescent Innuitian and Greenland ice sheets during the last glaciation. This paper focuses on the events and processes leading to the opening of the strait and the environmental response to establishment of the Arctic‐Atlantic throughflow. The study is based on sedimentological, mineralogical and foraminiferal analyses of radiocarbon‐dated cores 2001LSSL‐0014PC and TC from northern Baffin Bay. Radiocarbon dates on benthic foraminifera were calibrated with ΔR = 220±20 years. Basal compact pebbly mud is interpreted as a subglacial deposit formed by glacial overriding of unconsolidated marine sediments. It is overlain by ice‐proximal (red/grey laminated, ice‐proximal glaciomarine unit barren of foraminifera and containing >2 mm clasts interpreted as ice‐rafted debris) to ice‐distal (calcareous, grey pebbly mud with foraminifera indicative of a stratified water column with chilled Atlantic Water fauna and species associated with perennial and then seasonal sea ice cover) glacial marine sediment units. The age model indicates ice retreat into Smith Sound as early as c. 11.7 and as late as c. 11.2 cal. ka BP followed by progressively more distal glaciomarine conditions as the ice margin retreated toward the Kennedy Channel. We hypothesize that a distinct IRD layer deposited between 9.3 and 9 (9.4–8.9 1σ) cal. ka BP marks the break‐up of ice in Kennedy Channel resulting in the opening of Nares Strait as an Arctic‐Atlantic throughflow. Overlying foraminiferal assemblages indicate enhanced marine productivity consistent with entry of nutrient‐rich Arctic Surface Water. A pronounced rise in agglutinated foraminifers and sand‐sized diatoms, and loss of detrital calcite characterize the uppermost bioturbated mud, which was deposited after 4.8 (3.67–5.55 1σ) cal. ka BP. The timing of the transition is poorly resolved as it coincides with the slow sedimentation rates that ensued after the ice margins retreated onto land.

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confidence: 88%

Retreat of the Smith Sound Ice Stream in the Early Holocene

Jennings

Andrews

Oliver

et al. 2019

Boreas

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“…Core Kane2B age model was calibrated using a regional reservoir correction of Δ R = 240 ± 51 (Georgiadis et al, , ), while age models for cores 204 and 210 were calibrated using a regional age reservoir correction of Δ R = 140 ± 30 (Caron, St‐Onge, et al, 2019). These Δ R values were selected based on previous regional studies (Jackson et al, ; Jennings et al, ; Lloyd et al, ; Moros et al, ), and age models were validated with palaeomagnetic data (Caron, St‐Onge, et al, 2019). An improved version of core 204 age model was established with the addition of organic matter dating (J. Giraudeau, personal communication, December 2019).…”

Section: Methodsmentioning

confidence: 99%

Quantifying Provenance and Transport Pathways of Holocene Sediments From the Northwestern Greenland Margin

Caron

Montero‐Serrano

St‐Onge

et al. 2020

Paleoceanog and Paleoclimatol

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The mineralogical and geochemical compositions of three sediment cores from the northwestern Greenland continental margin (AMD14-204 and AMD14-210) and Kane Basin (AMD14-Kane2B) were investigated using quantitative X-ray diffraction and energy-dispersive X-ray fluorescence in order to document the impact of ice-ocean interactions on the sediment provenance and transport pathways during the Holocene. Unmixing of the sediment composition and ratios such as quartz/clays and K/Fe indicate that detrital sediments in cores from the northwest Greenland margin are derived mainly from Prøven granite and reworked Archean gneiss, whereas sediments from Kane Basin are derived mainly from detrital carbonate (Ellesmere Island) and Proterozoic gneiss (Humboldt Glacier). Mineralogical and geochemical signatures also reveal that changes in detrital sediment provenance and transport in the region are strongly interconnected to regional ice stream dynamics, especially during the early Holocene with strong meltwater discharge from the Greenland Ice Sheet associated with the end of deglaciation. With the establishment of milder conditions during the mid-Holocene and reduced glacial activity once ice sheets retreated inland, sediment inputs via ocean currents became more effective. Thus, detrital proxies in core AMD14-204, located in the Upernavik cross-shelf trough, support the hypothesis of an intensification of the West Greenland Current influence after 7.7 cal ka BP, which eventually affected the regional sediment dynamic by a greater contribution from basalt to the sediment supply. Finally, our results suggest that the interactions between climate, glacial dynamics, and surface ocean circulation controlled the paleoenvironmental changes observed in the three cores.

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“…; Jackson et al . ). Preliminary age models were computed for cores 204 and 210 using the CLAM 2.2 software (Blaauw ) and are shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

Holocene chronostratigraphy of northeastern Baffin Bay based on radiocarbon and palaeomagnetic data

Caron

St‐Onge

Montero‐Serrano

et al. 2018

Boreas

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The northeastern Baffin Bay continental margin, which experiences high sediment accumulation rates, is an excellent location to study Holocene sedimentary variations. However, it is often difficult to obtain reliable chronologies of the sediment archives using traditional methods (δ18O and radiocarbon) due to specific oceanographic conditions (e.g. corrosive bottom waters). Here we propose a chronostratigraphy of three cores collected on the northwestern Greenland margin (AMD14‐204, AMD14‐210 and AMD14‐Kane2B) based on a combination of radiocarbon dating and palaeomagnetic records. Geophysical properties of discrete samples were used to verify the reliability of the palaeomagnetic records. Palaeomagnetic analyses indicate a strong and stable natural remanent magnetization carried by low coercivity ferrimagnetic minerals (magnetite) in the pseudo‐single domain grain size range. Correlation of the full palaeomagnetic vector (inclination, declination, and relative palaeointensity) was used to establish a reliable chronostratigraphical framework for two of the cores (AMD14‐204 and AMD14‐210) and to propose an original palaeomagnetic record for the previously 14C‐dated core AMD14‐Kane2B that covers most of the Holocene. Overall, this new chronostratigraphy allowed improvement of the timing of the main palaeoenvironmental changes that occurred in this area during the Holocene.

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Asynchronous instability of the North American-Arctic and Greenland ice sheets during the last deglaciation

Cited by 42 publications

References 88 publications

Retreat of the Smith Sound Ice Stream in the Early Holocene

Retreat of the Smith Sound Ice Stream in the Early Holocene

Quantifying Provenance and Transport Pathways of Holocene Sediments From the Northwestern Greenland Margin

Holocene chronostratigraphy of northeastern Baffin Bay based on radiocarbon and palaeomagnetic data

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