The plankton community of the Kara Sea in early spring     

Sazhin  A. F.  Mosharov  S. A.  Romanova  N. D.  Belyaev  N. A.  Khlebopashev  P. V.  Pavlova  M. A.  Druzhkova  E. I.  Flint  M. V.  Kopylov  A. I.  Zabotkina  E. A.  Ishkulov  D. G.  Makarevich  P. R.  Pasternak  A. F.  Makkaveev  P. N.  Drozdova  A. N. 《Oceanology》2017,57(1):222-224

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Aggradational lobe fringes: The influence of subtle intrabasinal seabed topography on sediment gravity flow processes and lobe stacking patterns          下载免费PDF全文

Yvonne T. Spychala  David M. Hodgson  Christopher J. Stevenson  Stephen S. Flint 《Sedimentology》2017,64(2):582-608

Seabed topography is ubiquitous across basin‐floor environments, and influences sediment gravity flows and sediment dispersal patterns. The impact of steep (several degrees) confining slopes on sedimentary facies and depositional architecture has been widely documented. However, the influence of gentle (fraction of a degree) confining slopes is less well‐documented, largely due to outcrop limitations. Here, exceptional outcrop and research borehole data from Unit A of the Permian Laingsburg Formation, South Africa, provide the means to examine the influence of subtle lateral confinement on flow behaviour and lobe stacking patterns. The dataset describes the detailed architecture of subunits A.1 to A.6, a succession of stacked lobe complexes, over a palinspastically restored 22 km across‐strike transect. Facies distributions, stacking patterns, thickness and palaeoflow trends indicate the presence of a south‐east facing low angle (fraction of a degree) lateral intrabasinal slope. Interaction between stratified turbidity currents with a thin basal sand‐prone part and a thick mud‐prone part and the confining slope results in facies transition from thick‐bedded sandstones to thin‐bedded heterolithic lobe fringe‐type deposits. Slope angle dictates the distance over which the facies transition occurs (hundreds of metres to kilometres). These deposits are stacked vertically over tens of metres in successive lobe complexes to form an aggradational succession of lobe fringes. Extensive slides and debrites are present at the base of lobe complexes, and are associated with steeper restored slope gradients. The persistent facies transition across multiple lobe complexes, and the mass flow deposits, suggests that the intrabasinal slope was dynamic and was never healed by deposition during Unit A times. This study demonstrates the significant influence that even subtle basin‐floor topography has on flow behaviour and depositional architecture of submarine lobe complexes. In addition, we present a new aggradational lobe fringe facies associations and recognition criteria for subtle confinement in less well‐exposed and subsurface basin fills.  相似文献   

Distribution and Grazing of Dominant Zooplankton Species in the Ob Estuary: Influence of the Runoff Regime     

A.V. Drits  A.F. Pasternak  M.V. Flint 《Estuaries and Coasts》2017,40(4):1082-1095

Major interactions between terrestrial and marine environments in the Kara Sea occur within the estuaries of the largest Siberian rivers, the Ob and Yenisei. Mesozooplankton community plays an important role in the transformation of allochthonous organic matter. All published data on zooplankton activity in the Ob Estuary have been obtained for the period of decreased river discharge. The aim of our study was to assess zooplankton distribution and grazing under various hydrological regimes (high-low river discharge and varying wind direction) in order to better understand the mechanisms governing this process. The study was carried out along a quasi-latitudinal transect in the Ob Estuary at the beginning of August (high discharge) and end of September 2010 (decreased discharge) and end of August 2014 (high discharge and onshore winds). Zooplankton grazing was assessed with the gut fluorescent approach. Under high river discharge, zooplankton biomass was low (mean 98 mg wet weight m^?3), peaks of species abundance were spatially separated, and grazing did not exceed 2% of phytoplankton biomass. Weakening river discharge at the end of September led to the formation of hydrographic fronts, and zooplankton biomass was an order of magnitude higher (mean value 947 mg wet weight m^?3) with dense local aggregations with biomass reaching 3600 mg wet weight m^?3. These aggregations formed a pelagic “biofilter” grazing up to 26% of phytoplankton biomass per day. The peaks of abundance of the majority of species coincided at the pronounced hydrographic front forming dense local aggregations with biomass reaching 3600 mg wet weight m^?3. These aggregations formed a pelagic biofilter utilizing daily up to 26% of phytoplankton biomass.  相似文献   

Picophytoplankton of the Laptev Sea in Autumn     

Belevich  T. A.  Ilyash  L. V.  Arashkevich  E. G.  Flint  M. V. 《Doklady Earth Sciences》2019,484(2):207-210

Doklady Earth Sciences - The abundance and biomass of picophytoplankton, the total concentration of chlorophyll a, and the contribution of the picofraction to chlorophyll a were studied in the...  相似文献   

Reply     

Gary Hampson  Harald Stollhofen  & Steve Flint 《Sedimentology》2001,48(5):1179-1186

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Physical evidence of Quaternary climatic change     

Richard Foster Flint 《Quaternary Research》1976,6(4):519-528

Changes of climate have characterized parts, and at times apparently all, of Earth's surface. Changes that have occurred during the Quaternary period have special significance because, being comparatively recent, they are revealed by physical geologic features that are still at or near the surface, as yet little damaged by erosion. Although some of these features can be interpreted in terms that are broadly quantitative, most are still only qualitative in that they are limited to specifying climatic parameters that are positive or negative relative to those prevailing today in the same area. The common parameters indicated by the physical evidence include temperature (mean annual or summer) and precipitation (mean annual or seasonal). More rarely directions and minimum speeds of effective winds can be specified. A useful basis for reconstructions of former climates is a checklist of the relict geologic features from which climatic inferences can be drawn. Such a list is given here.  相似文献   

Three theories in time     

Richard Foster Flint 《Quaternary Research》1974,4(1):1-8

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Ecological effects from the balance between new and recycled nitrogen in Texas coastal waters     

R. Warren Flint  Gary L. Powell  Richard D. Kalke 《Estuaries and Coasts》1986,9(4):284-294

Benthic nutrient recycling is a significant source of dissolved nitrogen for south Texas coastal waters in the region of the Corpus Christi Bay estuary. Studies indicate that 90% of the dissolved nitrogen supply for phytoplankton production is derived from sediments in the upper-estuary, whereas benthic regeneration supplies only 33% of the dissolved nitrogen required for primary production outside the barrier island in coastal waters (15 m depth). In the upper-estuary relationships were observed between fluvial flow, water-column dissolved nitrogen, and phytoplankton productivity. In the middle-estuary relationships were observed between sediment recycling rates and water-column dissolved nitrogen. Beyond the barrier island, relationships were observed between fluvial flow and water-column dissolved nitrogen during high flow periods, while benthic regeneration appeared to be the major nutrient source during low flow periods. We suggest that combined effects from new and recycled nutrient sources buffer south Texas coastal productivity against long periods of low nutrient input from fluvial flow. The comparison of biological responses at several trophic levels to temporal variability in nitrogen recycling and fluvial flow indicated the importance of freshwater nitrogen inputs in stimulating primary production. Freshwater nitrogen inputs also appeared to sustain long-term productivity by replacing nutrients lost from the system by extended reliance upon recycling.  相似文献   

Estuarine benthos: Long-term community structure variations,corpus Christi Bay,Texas     

R. W. Flint  J. A. Younk 《Estuaries and Coasts》1983,6(2):126-141

A study of the benthic communities in Corpus Christi Bay was carried out between 1974 and 1979 to identify both natural and human-induced variations in community dynamics of the benthos over a long time period of monthly samples collection. General results of the investigation were comparable to previous shorter-term studies of this estuary in respect to species list of dominant fauna, total densities and species diversity measures. The present study emphasized two habitats: a channel 15 m deep and a shoal less than 3.5 m deep. Channel stations exhibited lower species numbers, densities, and species diversity than shoal sites but in contrast showed more even distributions of population numbers between species (equitability) than shoal sites. Hierarchical classification procedures identified community structure patterns that were associated with a major disturbance to the area, dredging, as well as minor, more frequent disturbances associated with large ship traffic and shrimp trawling activities in the channel. The community variable of species number and total density were also related to changes in salinity patterns in the study area. The results of this long-term study illustrated the resilience of benthic communities to disturbance. They also provided supportive evidence to hypotheses concerning the high resistence of communities to disturbance in inconstant environments and the source of colonists in these environments after a major disturbance to the bottom.  相似文献   

Sedimentary Waves and Reconstruction of Bottom Currents in the Novaya Zemlya Trough of the Kara Sea     

Baranov  B. V.  Flint  M. V.  Rimskiy-Korsakov  N. A.  Poyarkov  S. G.  Dozorova  K. A. 《Doklady Earth Sciences》2021,498(1):432-435

Doklady Earth Sciences - Reconstruction of bottom currents has been performed for the first time using the distribution of sedimentary waves in the Novaya Zemlya Trough in the Kara Sea based on the...  相似文献