Onset and growth of Trough-Mouth Fans on the North-Western Barents Sea margin – implications for the evolution of the Barents Sea/Svalbard Ice Sheet

The distribution of ice‐rafted detritus (IRD) is studied in three cores from the western Svalbard slope (1130–1880 m water depth, 76–78°N) covering the period 74–0 ka. The aim was to provide new insight into the dynamics of the Svalbard–Barents Sea Ice Sheet during Marine Isotope Stages (MIS) 4–1 to get a better understanding of ice‐sheet interactions with changes in ocean circulation and climate on orbital and millennial (Dansgaard–Oeschger events of stadial–interstadial) time scales. The results show that concentration, flux, composition and grain‐size of IRD vary with climate and ocean temperature on both orbital and millennial time scales. The IRD consists mainly of fragments of siltstones and mono‐crystalline transparent quartz (referred to as ‘quartz’). IRD dominated by siltstones has a local Svalbard–Barents Sea source, while IRD dominated by quartz is from distant sources. Local siltstone‐rich IRD predominates in warmer climatic phases (interstadials), while the proportion of allochthonous quartz‐rich IRD increases in cold phases (glacials and stadials/Heinrich events). During the Last Glacial Maximum and early deglaciation at 24–16.1 ka, the quartz content reached up to >90%. In warm climate, local iceberg calving apparently increased and the warmer ocean surface caused faster melting. During the glacial maxima (MIS 4 and MIS 2) and during cold stadials and Heinrich events, the local ice‐sheets must have been relatively stable with low ablation. During ice retreat phases of the MIS 4/3 and MIS 2/1 transitions, maxima in IRD deposition were dominated by local coarse‐grained IRD. These maxima correlate with episodes of climate warming, indicating a rapid, stepwise retreat of the Svalbard–Barents Sea Ice Sheet in phase with millennial‐scale climate oscillations.

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“…; Rebesco et al . ). Today, Atlantic Surface Water flows northward into the Arctic Ocean together with Greenland Sea Intermediate Water (Fig.…”

Section: Physical Settingmentioning

confidence: 97%

Ice‐rafting patterns on the western Svalbard slope 74–0 ka: interplay between ice‐sheet activity, climate and ocean circulation

Jessen¹,

Rasmussen

2018

Boreas

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“…Debris flows are ubiquitous on continental slopes seaward of cross-shelf troughs that were occupied by ice streams (Figs. 10 and 11;Laberg and Vorren, 1996;King et al, 1998;Taylor et al, 2002a;Dowdeswell et al, 2014;Rebesco et al, 2014). Deposition of debrites results in the formation of trough mouth fans, the primary depositional landform on many northern hemisphere margins Dahlgren et al, 2002;Elverhøi et al, 2002;Taylor et al, 2002a;Cofaigh et al, 2003;Dahlgren et al, 2005;Nielsen et al, 2005;Rebesco et al, 2014).…”

Section: Linking the Source To The Sink: Glacigenic Signal Transfermentioning

confidence: 99%

“…10 and 11;Laberg and Vorren, 1996;King et al, 1998;Taylor et al, 2002a;Dowdeswell et al, 2014;Rebesco et al, 2014). Deposition of debrites results in the formation of trough mouth fans, the primary depositional landform on many northern hemisphere margins Dahlgren et al, 2002;Elverhøi et al, 2002;Taylor et al, 2002a;Cofaigh et al, 2003;Dahlgren et al, 2005;Nielsen et al, 2005;Rebesco et al, 2014). Trough mouth fans occur wherever slopes are b4° (Cofaigh et al, 2003;; on steeper slopes, gravity flows supply sediment to deep submarine basins via large submarine channels (Dobson et al, 1998;Reece et al, 2011;Garcia et al, 2012;Walton et al, 2014).…”

Section: Linking the Source To The Sink: Glacigenic Signal Transfermentioning

confidence: 99%

“…Dowdeswell et al (2008b) and Ottesen and Dowdeswell (2009). Establishing links between lithostratigraphy and glacial geomorphology requires identifying the genesis of the sedimentary signal, which is most easily accomplished in currently glaciated settings. Interpreting the ice influence on strata formation depends on recognizing distinctive lithofacies and/or seismic-facies assemblages characteristic of glacial settings (e.g., Svendsen et al, 1992;Faleide et al, 1996;Dowdeswell et al, 1998;Licht et al, 1999;Anderson et al, 2002;Powell and Cooper, 2002;McKay et al, 2009;Cowan et al, 2010;Dowdeswell and Fugelli, 2012;Hambrey and Glasser, 2012;Hogan et al, 2012;Kirshner et al, 2012;Dowdeswell et al, 2014;Larter et al, 2014;Rebesco et al, 2014). Many diagnostic lithofacies criteria for recognizing glacigenic processes depend on examination of clast fabric, grain orientation, physical properties, and biofacies (Powell, 1983;Powell and Molnia, 1989;Eyles and Eyles, 1992;Dowdeswell et al, 1998;Wellner et al, 2001;Cofaigh et al, 2007;Garcia et al, 2011;Cowan et al, 2012Cowan et al, , 2014Hambrey and Glasser, 2012;Kirshner et al, 2012;Larter et al, 2014).…”

Section: The Sink-fidelity Of the Glacigenic Signalmentioning

confidence: 99%

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The role of the cryosphere in source-to-sink systems

Jaeger

Koppes

2016

Earth-Science Reviews

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“…A shift to more chaotic deposition occurs in GII, characterized by glacigenic debris flows, slide scars, and blocks of intact sediments originating from the outer shelf [ Andreassen et al ., ; Laberg et al ., ]. This event coincides with the first documented shelf edge glaciations in the western Barents Sea during the Early‐Middle Pleistocene (1.3–1.5 Ma) [ Faleide et al ., ; Butt et al ., ; Andreassen et al ., ; Rebesco et al ., ], as well as the first signs of extensive glacial erosion on the Yermak Plateau [ Mattingsdal et al ., ]. Unit GIII comprises mainly large debris flows deposited during full‐glacial conditions, with sparse occurrence of glacimarine sediments [ Laberg et al ., ].…”

Section: Chronologymentioning

confidence: 99%

Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a paleobenchmark for models of marine ice sheet deglaciation

Patton

Andreassen

Bjarnadóttir

et al. 2015

Reviews of Geophysics

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Our understanding of processes relating to the retreat of marine‐based ice sheets, such as the West Antarctic Ice Sheet and tidewater‐terminating glaciers in Greenland today, is still limited. In particular, the role of ice stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, a marine‐based ice sheet has waxed and waned over the Barents Sea continental shelf, characterized by a number of ice streams that extended to the shelf edge and subsequently collapsed during periods of climate and ocean warming. Increasing availability of offshore and onshore geophysical data over the last decade has significantly enhanced our knowledge of the pattern and timing of retreat of this Barents Sea ice sheet (BSIS), particularly so from its Late Weichselian maximum extent. We present a review of existing geophysical constraints that detail the dynamic evolution of the BSIS through the last glacial cycle, providing numerical modelers and geophysical workers with a benchmark data set with which to tune ice sheet reconstructions and explore ice sheet sensitivities and drivers of dynamic behavior. Although constraining data are generally spatially sporadic across the Barents and Kara Seas, behaviors such as ice sheet thinning, major ice divide migration, asynchronous and rapid flow switching, and ice stream collapses are all evident. Further investigation into the drivers and mechanisms of such dynamics within this unique paleo‐analogue is seen as a key priority for advancing our understanding of marine‐based ice sheet deglaciations, both in the deep past and in the short‐term future.

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Onset and growth of Trough-Mouth Fans on the North-Western Barents Sea margin – implications for the evolution of the Barents Sea/Svalbard Ice Sheet

Cited by 33 publications

References 50 publications

Ice‐rafting patterns on the western Svalbard slope 74–0 ka: interplay between ice‐sheet activity, climate and ocean circulation

Ice‐rafting patterns on the western Svalbard slope 74–0 ka: interplay between ice‐sheet activity, climate and ocean circulation

The role of the cryosphere in source-to-sink systems

Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a paleobenchmark for models of marine ice sheet deglaciation

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