Central Arctic Ocean Sediment Texture: A Key to Ice Transport Mechanisms

Clark, David L.; Hanson, Arnold M.

doi:10.1007/978-1-4613-3793-5_7

Cited by 86 publications

(83 citation statements)

References 21 publications

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“…As ice-rafted debris (IRD) we interpret all lithic grains > 250 µm, except for unweathered volcanic glass. In the high latitudes, such coarse particles can be transported into a deep ocean basin preferentially by icebergs while sea ice mainly transports finer material (Clark and Hanson, 1983;Nürnberg et al, 1994).…”

Section: Methodsmentioning

confidence: 99%

Water mass evolution of the Greenland Sea since late glacial times

2014

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Abstract. Four sediment cores from the central and northern Greenland Sea basin, a crucial area for the renewal of North Atlantic deep water, were analyzed for planktic foraminiferal fauna, planktic and benthic stable oxygen and carbon isotopes as well as ice-rafted debris to reconstruct the environmental variability in the last 23 kyr. During the Last Glacial Maximum, the Greenland Sea was dominated by cold and sea-ice bearing surface water masses. Meltwater discharges from the surrounding ice sheets affected the area during the deglaciation, influencing the water mass circulation. During the Younger Dryas interval the last major freshwater event occurred in the region. The onset of the Holocene interglacial was marked by an increase in the advection of Atlantic Water and a rise in sea surface temperatures (SST). Although the thermal maximum was not reached simultaneously across the basin, benthic isotope data indicate that the rate of overturning circulation reached a maximum in the central Greenland Sea around 7 ka. After 6-5 ka a SST cooling and increasing sea-ice cover is noted. Conditions during this so-called "Neoglacial" cooling, however, changed after 3 ka, probably due to enhanced sea-ice expansion, which limited the deep convection. As a result, a well stratified upper water column amplified the warming of the subsurface waters in the central Greenland Sea, which were fed by increased inflow of Atlantic Water from the eastern Nordic Seas. Our data reveal that the Holocene oceanographic conditions in the Greenland Sea did not develop uniformly. These variations were a response to a complex interplay between the Atlantic and Polar water masses, the rate of sea-ice formation and melting and its effect on vertical convection intensity during times of Northern Hemisphere insolation changes.

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Section: Methodsmentioning

confidence: 99%

Water mass evolution of the Greenland Sea since late glacial times

2014

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“…1). The most important sediment transport in this part of the basin probably occurs in a near bottom nepheloid layer (Hunkins et al, 1969) and as the vertical £ux from fallout of biogenic matter and ice transported lithic material (Clark and Hanson, 1983;Reimnitz et al, 1994).…”

Section: A Submarine Fan In the Amundsen Basinmentioning

confidence: 99%

A submarine fan in the Amundsen Basin, Arctic Ocean

et al. 2004

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Seismic reflection data from drifting ice stations and an icebreaker survey document the presence of a submarine fan along the east flank of the Lomonosov Ridge in the Amundsen Basin, Arctic Ocean. The fan extends from a source area at the North Greenland and Canadian Arctic continental margin to the North Pole. The fan probably developed in response to the combined effect of increased glacial sediment input during the Plio^Pleistocene and topographically confined transport of glacial debris in the deep sea passage between Lincoln Sea margin and the southern end of the Lomonosov Ridge. ß

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“…Previous investigations of ice rafting, sediment composition, and provenance of ice-rafted sediment in the Arctic Ocean based on the gravelsized fraction are limited. Such deposits in the central Arctic Ocean were investigated by Schwarzacher and Hunkins (1961); Clark et al (1980); Clark and Hanson (1983) and shelf gravels in the Beaufort Sea were investigated by Rodeick (1979), and Mowatt and Naidu (1989). Vassmyr and Vorren (1990) examined the coarse fraction of glacial ice-rafted clasts from cores obtained in the southern Barents Sea, and they present a detailed lithologic description of clast composition and relate the clasts to adjacent glaciated terranes.…”

Section: Introductionmentioning

confidence: 99%