Timing and significance of glacially influenced mass-wasting in the submarine channels of the Greenland Basin

Cofaigh, Colm Ó; Dowdeswell, Julian A.; Evans, Jeffrey; Kenyon, Neil H.; Taylor, J.; Mienert, Jürgen; Wilken, Manon

doi:10.1016/j.margeo.2004.02.009

Cited by 93 publications

(91 citation statements)

References 49 publications

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“…In South East Greenland, for example, Jennings et al (2006) placed the ice sheet margin in the Kangerdlussuaq Trough area at the shelf edge at 17 cal ka BP, whilst to the south of Ammassalik, Kuijpers et al (2003) argue that the central shelf was ice free by 15 cal ka BP. Further to the north, Ó Cofaig et al (2004) present marine geophysical and sediment core evidence that provide strong support for ice sheet extent well onto the continental shelf, perhaps reaching as far as the shelf edge. This view has been supported more recently by the mapping of the Westwind ice stream across the continental shelf in Northeast Table 1 Studies in this issue shown on the map in Fig.…”

Section: Greenland Ice Sheetmentioning

confidence: 76%

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

Jakobsson

Long

Inǵólfsson

et al. 2010

Quaternary Science Reviews

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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.

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Section: Greenland Ice Sheetmentioning

confidence: 76%

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

Jakobsson

Long

Inǵólfsson

et al. 2010

Quaternary Science Reviews

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“…1), and reaching the PD margin by 7.4 ka BP (red star, Fig. 1) (Cofaigh et al, 2004;Evans et al, 2002). Along the SE margin, the retreat from the outer to inner shelf is highly asynchronous, retreating from the outer Kangerdlugssuaq Trough at ∼ 17.8 ka BP (dark blue triangle, Fig.…”

Section: Observational Datamentioning

confidence: 98%

“…1), specifically to the shelf break along the SW, north, and central east at the LGM. This evidence includes moraines, grounding zone wedges , large-scale glacial lineations (Cofaigh et al, 2004), and glacio-marine sediments dated and analysed from offshore cores (Jennings et al, 2006). Table 1 provides an overview of the asynchronous nature of the timing of retreat from this expanded glacial maximum towards the PD margin.…”

Section: Observational Datamentioning

confidence: 99%

Simulation of the Greenland Ice Sheet over two glacial–interglacial cycles: investigating a sub-ice- shelf melt parameterization and relative sea level forcing in an ice-sheet–ice-shelf model

et al. 2018

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Abstract. Observational evidence, including offshore moraines and sediment cores, confirm that at the Last Glacial Maximum (LGM) the Greenland ice sheet (GrIS) expanded to a significantly larger spatial extent than seen at present, grounding into Baffin Bay and out onto the continental shelf break. Given this larger spatial extent and its close proximity to the neighbouring Laurentide Ice Sheet (LIS) and Innuitian Ice Sheet (IIS), it is likely these ice sheets will have had a strong non-local influence on the spatial and temporal behaviour of the GrIS. Most previous paleo ice-sheet modelling simulations recreated an ice sheet that either did not extend out onto the continental shelf or utilized a simplified marine ice parameterization which did not fully include the effect of ice shelves or neglected the sensitivity of the GrIS to this non-local bedrock signal from the surrounding ice sheets.In this paper, we investigated the evolution of the GrIS over the two most recent glacial-interglacial cycles (240 ka BP to the present day) using the ice-sheet-ice-shelf model IMAU-ICE. We investigated the solid earth influence of the LIS and IIS via an offline relative sea level (RSL) forcing generated by a glacial isostatic adjustment (GIA) model. The RSL forcing governed the spatial and temporal pattern of sub-ice-shelf melting via changes in the water depth below the ice shelves.In the ensemble of simulations, at the glacial maximums, the GrIS coalesced with the IIS to the north and expanded to the continental shelf break to the southwest but remained too restricted to the northeast. In terms of the global mean sea level contribution, at the Last Interglacial (LIG) and LGM the ice sheet added 1.46 and −2.59 m, respectively. This LGM contribution by the GrIS is considerably higher (∼ 1.26 m) than most previous studies whereas the contribution to the LIG highstand is lower (∼ 0.7 m). The spatial and temporal behaviour of the northern margin was highly variable in all simulations, controlled by the sub-ice-shelf melting which was dictated by the RSL forcing and the glacial history of the IIS and LIS. In contrast, the southwestern part of the ice sheet was insensitive to these forcings, with a uniform response in all simulations controlled by the surface air temperature, derived from ice cores.

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“…Mass transport deposits (mtd) show similar reflection characteristics (Laberg and Vorren, 1995;Laberg and Vorren, 2000;Ó Cofaigh et al, 2004). Still, the source of the mtds remains a problem since the southern Mozambique Ridge represents a topographic high (2800 to 1500 m water depth, Figure 1 (Lutjeharms, 2006).…”

Section: Observationsmentioning

confidence: 98%

Palaeoceanographic Interpretation of a Seismic Profile From the Southern Mozambique Ridge, Southwestern Indian Ocean

Uenzelmann-Neben¹,

Watkeys²,

Kretzinger³

et al. 2011

South African Journal of Geology

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Seismic reflection data from the southern Mozambique Ridge, Southwestern Indian Ocean, show indications for a modification in the oceanic circulation system during the Neogene. Major reorganisations in the Indian Ocean circulation system accompanying the closure of the Indonesian Gateway led to the onset of current controlled sedimentation in the vicinity of the Mozambique Ridge at 14 Ma. The modifications in water mass properties and path are documented in changes in reflection characteristics in the Mozambique Ridge area. Correlating these with identified changes of the Nd isotope evolution in deep water masses the general present day large scale circulation in the southern Indian Ocean is suggested to have prevailed for the last 9 Ma. References should not be included in abstracts.SOUTH AFRICAN JOURNAL OF GEOLOGY, 2011, VOLUME 114. (Smith and Sandwell, 1997;Uenzelmann-Neben, 2005;Jokat, 2006 Lutjeharms, 1996).The Agulhas Current is the western boundary current of the Indian Ocean It extends to water depths greater than 2000 m and has a mean transport of 108 m 3 /s (Lutjeharms, 1996; De Ruijter et al., 1999). Southwest of Africa the Agulhas Current turns abruptly eastward in a tight retroflection loop and becomes known as the Agulhas Return Current. This current flows eastwards to the Agulhas Plateau where it forms a major northward loop around the plateau (Lutjeharms, 1996; De Ruijter et al., 1999). Data Acquisition and AnalysisThis study is based on seismic reflection data gathered at the southern Mozambique Ridge (Figure 1a) (Uenzelmann-Neben, 2005). The seismic reflection data were collected using a three GI-gun cluster as source and a 2.4 km long digital streamer system with 180 channels to record the data. A sample rate of 1 ms guaranteed a theoretical vertical resolution of 4 m. (Lutjeharms, 2006). SF= secondary faults.

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Timing and significance of glacially influenced mass-wasting in the submarine channels of the Greenland Basin

Cited by 93 publications

References 49 publications

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

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

Simulation of the Greenland Ice Sheet over two glacial–interglacial cycles: investigating a sub-ice- shelf melt parameterization and relative sea level forcing in an ice-sheet–ice-shelf model

Palaeoceanographic Interpretation of a Seismic Profile From the Southern Mozambique Ridge, Southwestern Indian Ocean

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