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

Abstract

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.

Late Quaternary geomorphology and sedimentary processes in the Zambezi turbidite system (Mozambique Channel)

“…26B), which are favorable to deposition by bottom currents (Miramontes, 2016). Generation of large sediment waves by bottom currents in unconfined settings is, for example, also found in the eastern Equatorial Pacific (Lonsdale and Malfait, 1974), in the Argentine Basin (Flood and Shor, 1988), in the western South Atlantic (Cunningham and Barker, 1996) and offshore NW-Svalbard (Hustoft et al, 2009;Forwick et al, 2015)..…”

Sedimentary model for mixed depositional systems along the Pacific margin of the Antarctic Peninsula: Decoding the interplay of deep-water processes

“…This cyclicity may match the ~100 kyr orbital cycles (Fig. 10), hinting at fluctuating hydrodynamic regimes and turbidite input in tandem with glacialinterglacial changes, modulated by short-range eccentricity (Clausen, 1998;Michels et al, 2001;Bart et al, 2007;Forwick et al, 2015;Salabarnada et al, 2018).…”

Recognizing key sedimentary facies and their distribution in mixed turbidite–contourite depositional systems: The case of the Pacific margin of the Antarctic Peninsula

“…(2021), cyclic variations of grain size, sedimentary structures, biogenic content, clay mineral provenance and IRD supply have been associated with changes in sea‐ice cover and grounded ice‐sheet advance/retreat across the adjacent continental shelf, implying that glaciations and deglaciations are responsible for variations in the supply of both terrigenous and biogenic particles. Other high‐latitude mixed systems have presented similar results, where changes in sedimentary facies and morphological features are associated with fluctuations in turbidity currents or along‐slope bottom current activity (Clausen, 1998; Escutia et al ., 2000; Michels et al ., 2001; Rasmussen et al ., 2003; Forwick et al ., 2015; García et al ., 2016; Salabarnada et al ., 2018). Climatic and sea‐level oscillations have also been tied to significant changes in turbidity current flows (Hubbard et al ., 2014) and to the hydrodynamic fluctuations of the bottom current (de Castro et al ., 2021).…”