Glacimarine Drainage Systems in Deep-sea: The NAMOC System of the Labrador Sea and its Sibling.

Palaeo-ice streams, trough mouth fans and high-latitude continental slope sedimentation

“…In the Ross Sea, sediment-laden meltwater released from the ice-stream front formed turbidity currents which eroded channels on the upper slope (Shipp et al 1999;Anderson 1999). Further downslope, the transition into the NAMOC channel system and its associated giant sandy braid-plain records discharge of bedload-rich meltwater directly onto the slope from the Hudson Strait ice stream (Hesse et al 1997b). Similarly, along the Labrador Sea margin, meltwater processes appear to have played a key role in sedimentation with deposition of fine-grained muds, which were subsequently channelled by turbidity currents (Hesse et al 1997a(Hesse et al , 1999.…”

“…The giant submarine braid plain that is associated with the NAMOC (Fig. 6) is composed of predominantly sandy and gravelly sediment and records deposition from bedload-rich meltwater discharges from the Hudson Strait ice stream (Hesse et al 1997b).…”

“…Similarly, along the Labrador Sea margin, meltwater processes appear to have played a key role in sedimentation with deposition of fine-grained muds, which were subsequently channelled by turbidity currents (Hesse et al 1997a(Hesse et al , 1999. Further downslope, the transition into the NAMOC channel system and its associated giant sandy braid-plain records discharge of bedload-rich meltwater directly onto the slope from the Hudson Strait ice stream (Hesse et al 1997b). Meltwater-related processes therefore impart considerable variety to the morphology and sedimentary architecture of continental slopes in front of palaeo-ice streams.…”

“…Map of the Labrador Sea showing the upslope branching pattern of tributary channels on the slope and distribution of major sediment facies (redrawn fromHesse et al 1997b). The inferred positions of major ice-sheet outlets (ice streams) along the Canadian margin are arrowed.…”

The relationship between ice sheets and submarine mass movements in the Nordic Seas during the Quaternary

“…These systems are hypothesised to be a consequence of hyperpycnal and hypopycnal flow formation (Piper and Hundert, 2002;Piper and Normark, 2009), the re-working of sediment by turbidity currents which has settled out from meltwater plumes that have been entrained southward by the Labrador Current and mass-wasting processes ( Fig. 26; Hesse et al, 1997;2004;Ó Cofaigh et al, 2003). Many of the channel and canyon systems subsequently coalesce to feed deep-sea channels such as the North Atlantic Mid-Ocean Channel (Piper, 2005).…”