Alternating Bottom-Current-Dominated and Gravity-Flow-Dominated Deposition in a Lower Slope and Rise Setting—Insights From the Seismic Geomorphology of the Western Scotian Margin, Eastern Canada

2012 ◽  
pp. 329-346
Author(s):  
D. CALVIN CAMPBELL ◽  
MARK E. DEPTUCK
Keyword(s):  
Gravity Flow ◽  
Bottom Current ◽  
Eastern Canada ◽  
Seismic Geomorphology ◽  
Lower Slope

Late Quaternary sedimentation in Baffin Bay

1987 ◽  
Vol 24 (9) ◽  
pp. 1833-1846 ◽  
Author(s):  
A. E. Aksu ◽  
David J. W. Piper
Keyword(s):  
Debris Flow ◽  
Late Quaternary ◽  
Ocean Basin ◽  
The Arctic ◽  
Bottom Current ◽  
Eastern Canada ◽  
Baffin Bay ◽  
Quaternary Glaciation ◽  
Continental Slopes ◽  
Channel Systems

Baffin Bay is a small ocean basin that connects the Arctic and Atlantic oceans. The adjacent continental shelves have been extensively reworked during Quaternary glaciation. The shelf break generally lies between 200 and 500 m. The continental slope passes directly into the abyssal plain of Baffin Bay basin without any major submarine canyon – deep-sea fan system being present, except for a large smooth sediment apron in northern Baffin Bay.On the basis of over 50 piston cores, six Quaternary sediment facies are distinguished from detrital mineralogy (reflected in colour) and sediment texture. Facies A, B, and C are predominantly ice-rafted or are debris flow deposits, each with a distinct mineralogy. Facies D is turbidites and bottom-current sorted sands, silts, and muds. Facies E is hemipelagic sediment. Facies F consists of sediments ranging from slumps, through debris flow deposits, to fine-grained turbidites, with a distinctive provenance in northern Baffin Bay.These sediment facies appear to be partly controlled by glacial conditions. Hemipelagic facies E predominates during the present interglacial. During glacial stages, facies D turbidites were deposited. They resulted from slumping of proglacial sediments on the continental slopes off Greenland and Baffin Island. Facies C and F occurred on the continental slopes at these times. Ice-rafted facies A and B predominate at several horizons, reflecting a rapid breakup of ice shelves in northern Baffin Bay and increased rates of iceberg melting within the Bay. Overall sedimentation rates are relatively low, reflecting dry-base ice sheets in source areas.Deep-sea channel systems floored by sorted coarse sediments and bounded by muddy levees are absent in Baffin Bay, in contrast to mid-latitude glaciated continental margins off eastern Canada. These channel systems are the result of melting of wet-base glaciers, which provide a localized supply of sediment that is sorted by ice margin processes. In Baffin Bay, most glacial sediments are derived by calving of icebergs, probably from dry-base glaciers. Sediments are gradually released over large areas as the bergs melt, and are subsequently redistributed by debris flows.

Deep-water sediment wave fields, bottom current sand channels and gravity flow channel-lobe systems: Gulf of Cadiz, NE Atlantic

Sedimentology ◽  
2003 ◽  
Vol 50 (3) ◽  
pp. 483-510 ◽  
Author(s):  
Edward L. Habgood ◽  
Neil H. Kenyon ◽  
Douglas G. Masson ◽  
Andrey Akhmetzhanov ◽  
Philip P. E. Weaver ◽  
...  
Keyword(s):  
Deep Water ◽  
Flow Channel ◽  
Gravity Flow ◽  
Bottom Current ◽  
Gulf Of Cadiz ◽  
Ne Atlantic ◽  
Sediment Wave ◽  
Wave Fields ◽  
Gulf Of Cádiz

Bottom-current deposits in the Miocene-Pliocene Misaki Formation, Izu forearc area, Japan

Island Arc ◽  
1998 ◽  
Vol 7 (3) ◽  
pp. 315-329 ◽  
Author(s):  
I NT AE L EE ◽  
Y UJIRO O GAWA
Keyword(s):  
Bottom Current

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

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