Material Fluxes on the Surface of the Earth (1994) / Chapter Skim
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Late Quaternary Flux of Eolian Dust to the Pelagic Ocean
Late Quaternary Flux of Eolian Dust to the Pelagic Ocean
Pages 116-124
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From page 116... ...
by the area of the global ocean results in an average deposition rate of 200 mg/cm2/kyr, but this value is too low for the nearshore regions and a factor of 4 or 5 high for the pelagic ocean. Detailed downcore records of eolian flux to the northwest Pacific document much higher fluxes during glacial times and accumulation minima during interglacials; this accumulation pattern matches the loess/soil stratigraphy of central China.
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From page 117... ...
Geographic Variation in Eolian Fluxes The input rate of dust to the pelagic oceans today (Holocene) ranges through three orders of magnitude, from low values of 1 or 2 mg/cm2/kyr in the center of the South Pacific to more than 1000 mg/cm2/kyr just downwind from the North African and Asian source regions.
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From page 118... ...
The most flux data exist for the North Pacific where essentially all of the eolian dust deposited comes from central and western China and Mongolia. That material is transported to the east by the westerlies and the westerly jet stream, then drifts south towards the equator and dominates eolian deposition all the way south to the Intertropical Convergence Zone (Merrill et al., 1989~.
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From page 119... ...
(Table 8.11. Holocene flux values in cores well away from the problems attendant to continental margin sedimentation are 400 to 500 mg/cm2/kyr in the region between the equator and about 10°N.
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From page 120... ...
A longer-term trend of increasing dust flux to the North Pacific in younger sediments during the past 500,000 yr is apparent (Figure 8.51. This observation, which suggests increasing late Pleistocene aridity in the eolian source region, is consistent with the observations of Pye and Li (1989)
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From page 121... ...
Five piston cores raised from the Equatorial Atlantic between about 5°N and 11°S provide a record of eolian dust flux to that part of the ocean over the past 300,000 yr (Figures 8.1 and 8.7~. Flux values at ODP drillsites north of the ITCZ have averaged 400 to 500 mg/cm2/kyr for the past 0.5 myr and may have been 50 percent or more higher in earlier portions of the Pleistocene (Ruddiman et al., 1989~.
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From page 122... ...
The shift in accumulation maxima from the assumed southern hemisphere pattern of interglacial maxima to the known northern hemisphere pattern of glacial-aged maxima implies a quasipermanent shift in the latitude of the Intertropical Convergence Zone at the time of the Mid-Brunhes Climate Event, from an earlier more southerly location to a younger position further north. The location RC11-210 constrains this latitudinal shift in the position of the ITCZ to be at least 5°.
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From page 123... ...
(19851. Eolian sedimentation in the northwest Pacific Ocean: A preliminary examination of the data from Deep Sea Drilling Project Sites 576 and 578, in Initial Reports of the Deep Sea Drilling Project 86, G
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From page 124... ...
Newberry (1991~. Late Pleistocene paleoclimatology of the central Equatorial Pacific: Flux patterns of biogenic sediments, Paleoceanography 6, 227-244.
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