Quaternary contourite drifts of the Western Spitsbergen margin

Laberg, Jan Sverre; Rebesco, Michele; Wåhlin, Anna; Schauer, Ursula; Beszczyńska-Möller, Agnieszka; Lucchi, Renata Giulia; Noormets, Riko; Accettella, Daniela; Zarayskaya, Yulia; Diviacco, Paolo

doi:10.1016/j.dsr.2013.05.013

Cited by 64 publications

(49 citation statements)

References 79 publications

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“…This gives a low average sedimentation rate of 4 cm kyr −1 , which may imply that upper Holocene and Younger Dryas sediments are missing. This is consistent with the stratigraphy of nearby cores, which also show significant sediment hiatuses at the surface [ Elverhøi et al ., ; Jessen et al ., ; Rebesco et al ., ].…”

Section: Resultsmentioning

confidence: 99%

Paleo‐methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard

Panieri

Graves

James

2016

Geochem Geophys Geosyst

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We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean warming may be fueling the destabilization of shallow methane hydrate. The d13 C values of benthic and planktonic foraminifera at the methane seep sites show distinct intervals with negative values (as low as 227.8&) that do not coincide with the present-day depth of the sulfate methane transition zone (SMTZ). These intervals are interpreted to record long-term fluctuations in methane release at the present-day landward limit of the gas hydrate stability zone (GHSZ). Shifts in the radiocarbon ages obtained from planktonic foraminifera toward older values are related to methane-derived authigenic carbonate overgrowths of the foraminiferal tests, and prevent us from establishing the chronology of seepage events. At shallower water depths, where seepage is not presently observed, no record of past methane seepage is recorded in foraminifera from sediments spanning the last 14 ka cal BP ( 14 C-AMS dating). d 13 C values of foraminiferal carbonate tests appear to be much more sensitive to methane seepage than other sediment parameters. By providing nucleation sites for authigenic carbonate precipitation, foraminifera thus record the position of even a transiently stable SMTZ, which is likely to be a characteristic of temporally variable methane fluxes.

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Section: Resultsmentioning

confidence: 99%

Paleo‐methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard

Panieri

Graves

James

2016

Geochem Geophys Geosyst

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“…Deposition was, consequently, expected to take usually place directly beneath such a water-mass contact or current core (e.g., Preu et al, 2013;Rebesco et al, 2013). We demonstrate, in addition, that the transition zone of two water masses is able to offer the medium for a high-energy regime because of episodically arriving oceanic density fronts.…”

Section: General Implications For Contourite Formationmentioning

confidence: 95%

Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)

Hanebuth

Zhang

Hofmann

et al. 2015

Quaternary Science Reviews

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“…Similar drifts have been described immediately north of the study area [61], as well as from other places along the continental slope off west Svalbard, e.g. the SE Vestnesa Ridge (1226 m water depth; [23]), the SW Vestnesa Ridge (1500-2500 m water depth; [24]), the western slope of the Yermak Plateau [21], as well as off Isfjorden and Bellsund (1200-800 m water depth; [57]; for locations, see Fig. 1).…”

Section: Overall Bathymetrymentioning

confidence: 76%

“…b Regional setting of the study area. SBF Sjubrebanken Fan Contourite-drift deposition dominated the overall sedimentary environment in the eastern Fram Strait since at least 11 Ma and numerous sediment drifts have been identified on the continental slope off western Svalbard, mainly at water depths exceeding 1200 m [7,21,23,24,41,57,61]. However, multiple escarpments north of the study area provide evidence of repeated downslope sediment transport ( [10,50]).…”

Section: Physiographymentioning

confidence: 99%

“…Contourite drifts along the margins and within the adjacent deep sea suggest that bottom currents flowing parallel to the slopes can dominate the long-term sedimentation at local to regional scales (e.g. [7,21,23,33,36,56,57]). However, gullies, channels and canyons provide evidence of repeated and focused downslope processes leading to erosion and slope incision over time.…”

Section: Introductionmentioning

confidence: 99%

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The Kongsfjorden Channel System offshore NW Svalbard: downslope sedimentary processes in a contour-current-dominated setting

Forwick

Laberg

Hass

et al. 2015

Arktos

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Submarine channel systems on and off glaciated continental margins can be up to hundreds of kilometres long, tens of kilometres wide and hundreds of metres deep. They result from repeated erosion and various downslope processes predominantly during glacial periods and can, therefore, provide valuable tools for the reconstruction of past ice-sheet dynamics. The Kongsfjorden Channel System (KCS) on the continental slope off northwest Svalbard provides evidence that downslope sedimentary processes are locally more dominant than regional along-slope sedimentation. It is a relatively short channel system (*120 km) that occurs at a large range of water depths (*250-4000 m) with slope gradients varying between 0°and 20°. Multiple gullies on the Kongsfjorden Trough Mouth Fan merge to small channels that further merge to a main channel. The overall location of the channel system is controlled by variations in slope gradients and the ambient regional bathymetry. The widest and deepest incisions occur in areas of the steepest slope gradients. The KCS has probably been active since *1 Ma when glacial activity on Svalbard increased and grounded ice expanded to the shelf break off Kongsfjorden repeatedly. Activity within the system was probably highest during glacials. However, reduced activity presumably took place also during interglacials.

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Quaternary contourite drifts of the Western Spitsbergen margin

Cited by 64 publications

References 79 publications

Paleo‐methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard

Paleo‐methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard

Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)

The Kongsfjorden Channel System offshore NW Svalbard: downslope sedimentary processes in a contour-current-dominated setting

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