Submarine landforms and shallow acoustic stratigraphy of a 400 km-long fjord-shelf-slope transect, Kangerlussuaq margin, East Greenland

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. (2014) 'A model of Greenland ice sheet deglaciation constrained by observations of relative sea level and ice extent.', Quaternary science reviews., 102 . pp. 54-84. Further information on publisher's website:http://dx.doi.org/10.1016/j.quascirev.2014.07.018Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Quaternary Science Reviews. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reected in this document. Changes may have been made to this work since it was submitted for publication. A denitive version was subsequently published in Quaternary Science Reviews, 102, 2014Reviews, 102, , 10.1016Reviews, 102, /j.quascirev.2014 Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACT An ice sheet model was constrained to reconstruct the evolution of the Greenland Ice Sheet (GrIS) from the Last Glacial Maximum (LGM) to present to improve our understanding of its response to climate change. The study involved applying a glaciological model in series with a glacial isostatic adjustment and relative sea-level (RSL) model. The model reconstruction builds upon the work of Simpson et al. (2009) through four main extensions: (1) a larger constraint database consisting of RSL and ice extent data; model improvements to the (2) climate and (3) sea-level forcing components; (4) accounting for uncertainties in non-Greenland ice. The research was conducted primarily to address datamodel misfits and to quantify inherent model uncertainties with the Earth structure and non-Greenland ice. Our new model (termed Huy3) fits the majority of observations and is characterised by a number of defining features. During the LGM, the ice sheet had an excess of 4.7 m ice-equivalent sea-level (IESL), which reached a maximum volume of 5.1 m IESL at 16.5 cal. ka BP. Modelled retreat of ice from the continental shelf progressed at different rates and timings in different sectors. Southwest and Southeast Greenland began to retreat from the continental shelf by ~16 to 14 cal. ka BP, thus responding in part to the Bølling-Allerød warm event (c. 14.5 cal. ka BP); subsequently ice at the southern tip of Greenland readvanced during the Younger Dryas cold event. In northern Greenland the ice retreated rapidly from the continental shelf upon the climatic recovery out of the Younger Dryas to present-day conditions. Upon entering the Holocene (11.7 cal. ka BP)...

Section: Ice Extent During Deglaciationmentioning

confidence: 99%

A model of Greenland ice sheet deglaciation constrained by observations of relative sea level and ice extent

Lecavalier¹,

Milne²,

Simpson³

et al. 2014

215

321

“…In this issue Dowdeswell et al (2010a) present new swath bathymetric imagery that identify drumlins and glacial lineations produced by a former ice stream that occupied the Kangerlussuaq Trough (Fig. 1).…”

Section: Referencementioning

confidence: 99%

New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling

Jakobsson

Long

Inǵólfsson

et al. 2010

a b s t r a c tTerrestrial and marine geological archives in the Arctic contain information on environmental change through Quaternary interglacialeglacial cycles. The Arctic Palaeoclimate and its Extremes (APEX) scientific network aims to better understand the magnitude and frequency of past Arctic climate variability, with focus on the "extreme" versus the "normal" conditions of the climate system. One important motivation for studying the amplitude of past natural environmental changes in the Arctic is to better understand the role of this region in a global perspective and provide base-line conditions against which to explore potential future changes in Arctic climate under scenarios of global warming. In this review we identify several areas that are distinct to the present programme and highlight some recent advances presented in this special issue concerning Arctic palaeo-records and natural variability, including spatial and temporal variability of the Greenland Ice Sheet, Arctic Ocean sediment stratigraphy, past ice shelves and marginal marine ice sheets, and the Cenozoic history of Arctic Ocean sea ice in general and Holocene oscillations in sea ice concentrations in particular. The combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean. This has important consequences for our understanding of the recent trend of declining sea ice, and calls for further research on causal links between Arctic climate and sea ice.

“…New constraints upon ice stream extent, thickness, and deglacial behaviour from the LGM to present have been established since the early 2000's both onshore (Bennike and Bjorck, 2002, Håkansson et al, 2007, Håkansson et al, 2009, Roberts et al, 2008, Roberts et al, 2009, Roberts et al, 2010, Roberts et al, 2013 and offshore (Ó Cofaigh et al, 2004, Evans et al, 2009, Dowdeswell et al, 2010. These have provided evidence for the existence of large ice streams across the West, Northeast and East Greenland continental shelves during the last glacial cycle (Lykke-Andersen, 1998, Ó Cofaigh et al, 2004, Evans et al, 2009, Dowdeswell et al, 2010.…”

Section: Introduction and Rationalementioning

confidence: 99%

Controls upon the Last Glacial Maximum deglaciation of the northern Uummannaq Ice Stream System, West Greenland

Lane

Roberts

Rea

et al. 2014

Citation for published item:vneD FF nd oertsD hFrF nd eD fFF nd ¡ y gofighD gF nd ieliD eF nd od¡ esD eF @PHIRA 9gontrols upon the vst qlil wximum deglition of the northern ummnnq se trem ystemD est qreenlndF9D uternry siene reviewsFD WP F ppF QPREQRRF Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractThe Uummannaq ice stream system (UISS) was a convergent cross-shelf ice stream system that operated in West Greenland during the Last Glacial Maximum (LGM). This paper presents new evidence constraining the geometry and evolution of the northern sector of the UISS and considers the factors controlling its dynamic behaviour. Geomorphological mapping, 21 new terrestrial cosmogenic nuclide (TCN) exposure ages, and radiocarbon dating constrain LGM warm-based ice stream activity in the north of the system up to 1400 m a.s.l. Intervening plateaux areas either remained ice free, or were covered by cold-based icefields. Beyond the inner fjords, topography and bathymetry forced ice flow southwards into the Uummannaq Trough, where it coalesced with ice from the south, and formed the trunk zone of the UISS.Deglaciation of the UISS began at 14.9 cal. kyr BP. Rapid retreat from the LGM limit was forced by an increase in air temperatures and rising sea level, enhanced by the bathymetric over- Greenland, which suggest ice had retreated beyond its present margin by 9-7 kyr. This demonstrates the potential importance of topographic control on calving margin stability, and its ability to override climatic forcing.