Marine environmental monitoring in the shelf zone of the Black Sea: Assessment of the current state of the pelagic ecosystem     

E. G. Arashkevich  N. E. Louppova  A. B. Nikishina  L. A. Pautova  V. K. Chasovnikov  A. V. Drits  O. I. Podymov  N. D. Romanova  R. R. Stanichnaya  A. G. Zatsepin  S. B. Kuklev  M. V. Flint 《Oceanology》2015,55(6):871-876

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Plankton distribution associated with frontal zones in the vicinity of the Pribilof Islands     

Mikhail V. Flint  Irina N. Sukhanova  Alexander I. Kopylov  Sergei G. Poyarkov  Terry E. Whitledge 《Deep Sea Research Part II: Topical Studies in Oceanography》2002,49(26)

We studied the effect of four types of fronts, the coastal front, the middle front, the shelf partition front and the shelf break front on the quantitative distribution and the composition of plankton communities in the Pribilof area of the eastern Bering Sea shelf in late spring and summer of 1993 and 1994. The coastal fronts near St. Paul and St. George Islands and the coastal domains encircled by the fronts featured specific taxonomic composition of planktonic algae, high abundance and production of phytoplankton, as well as large numbers of heterotrophic nanoplankton. The coastal fronts also were characterized by high values of total mesozooplankton biomass, high concentrations of Calanus marshallae, as well as relatively high abundances of Parasagitta setosa and Euphausiacea compared to surrounding shelf waters. We hypothesize that wind-induced erosion of a weak thermocline in the inner part of the coastal front as well as transfrontal water exchange in subthermocline layers result in nutrient enrichment of the euphotic layer in the coastal fronts and coastal domains in summer time. This leads to prolonged high primary production and high phytoplankton biomass. In this paper a new type of front—the shelf partition front located 45–55 km to the north-east off St. Paul Island—is described, which is assumed to be formed by the flux of oceanic domain waters onto the shelf. This front features a high abundance of phytoplankton and a high level of primary production compared to the adjacent middle shelf. Near the southwestern periphery of the front a mesozooplankton peak occurred, composed of C. marshallae, with biomass in the subthermocline layer, reaching values typical for the shelf break front and the highest for the area. High abundance of phyto- and zooplankton as well as heterotrophic nanoplankton and elevated primary production were most often observed in the area adjacent to the shelf break front at its oceanic side. The phyto- and mesozooplankton peaks here were formed by oceanic community species. The summer levels of phytoplankton numbers, biomass and primary production in the shelf break frontal area were similar to those reported for the outer and middle shelf during the spring bloom and the coastal domains and coastal fronts in summer. In the environment with a narrow shelf to the south of St. George Island, the mesozooplankton peak was observed at the inner side of the shelf break front as close as 20 km from the island shore and was comprised of a “mixed” community of shelf and oceanic species. The biomass in the peak reached the highest values for the Pribilof area at 2.5 g mean wet weight m⁻³ in the 0–100 m layer. Details of the taxonomic composition and the numbers and production of phytoplankton hint at the similarity of processes that affect the phytoplankton summer community in the coastal domains of the islands, at the coastal fronts, and at the oceanic side of the shelf break front. The middle front was the only one that had no effect on plankton composition or its quantitative characteristics in June and July. Location of a variety of frontal productive areas within 100 km of the Pribilof Islands creates favorable foraging habitat for higher trophic level organisms, including sea birds and marine mammals, populating the islands.  相似文献   

Social and Geographic Contexts of Water Concerns in Utah     

Courtney G. Flint  Xin Dai  Douglas Jackson-Smith  Joanna Endter-Wada  Sara K. Yeo  Rebecca Hale 《社会与自然资源》2017,30(8):885-902

Public concerns about water issues are key considerations in responding to changing hydrologic conditions. Literature is mixed on the social profiles associated with resource-related risks. Using data from a household survey, we compare concerns about water shortage, climate change impacts on water supply, poor water quality, and flooding. We assess the combined influence of social and locational factors on each concern and variations across three valleys in northern Utah. Generalized linear mixed modeling is used, given the ordinal nature of most variables. Water shortage was the greatest concern, and female, older, nonwhite, and recreationally active respondents were generally more concerned about water issues than their counterparts. Education, income, and religious identity presented more complicated relationships with water concerns, with significant interaction effects with valley geography. This study has implications for improving public involvement in risk management and engendering support for future water policy and planning strategies to address these risks.  相似文献   

Stratigraphic hierarchy and three-dimensional evolution of an exhumed submarine slope channel system     

Daniel Bell  David M. Hodgson  Anna S. M. Pontén  Larissa A. S. Hansen  Stephen S. Flint  Ian A. Kane 《Sedimentology》2020,67(6):3259-3289

Submarine slope channel systems have complicated three-dimensional geometries and facies distributions, which are challenging to resolve using subsurface data. Outcrop analogues can provide sub-seismic-scale detail, although most exhumed systems only afford two-dimensional constraints on the depositional architecture. A rare example of an accessible fine-grained slope channel complex set situated in a tectonically quiescent basin that offers seismic-scale, down-dip and across-strike exposures is the Klein Hangklip area, Tanqua-Karoo Basin, South Africa. This study investigates the three-dimensional architecture of this channel complex set to characterise the stratigraphic evolution of a submarine channel-fill and the implications this has for both sediment transport to the deep-oceans and reservoir quality distribution. Correlated sedimentary logs and mapping of key surfaces across a 3 km² area reveal that: (i) the oldest channel elements in channel complexes infill relatively deep channel cuts and have low aspect-ratios. Later channel elements are bound by comparatively flat erosion surfaces and have high aspect-ratios; (ii) facies changes across depositional strike are consistent and predictable; conversely, facies change in successive down depositional dip positions indicating longitudinal variability in depositional processes; (iii) stratigraphic architecture is consistent and predictable at seismic-scale both down-dip and across-strike in three-dimensions; (iv) channel-base-deposits exhibit spatial heterogeneity on one to hundreds of metres length-scales, which can inhibit accurate recognition and interpretations drawn from one-dimensional or limited two-dimensional datasets; and (v) channel-base-deposit character is linked to sediment bypass magnitude and longevity, which suggests that time-partitioning is biased towards conduit excavation and maintenance rather than the fill-phase. The data provide insights into the stratigraphic evolution and architecture of slope channel-fills on fine-grained continental margins and can be utilised to improve predictions derived from lower resolution and one-dimensional well data.  相似文献   

Stratigraphic evolution of the upper slope and shelf edge in the Karoo Basin, South Africa     

R. Wild  S. S. Flint  D. M. Hodgson 《Basin Research》2009,21(5):502-527

The Permian Ecca Group of the Karoo Basin, South Africa preserves an extensive well-exposed siliciclastic basin floor, slope and shelf-edge delta succession. The Kookfontein Formation includes multiple sedimentary cycles that display clinoform geometries and are interpreted to represent the deposits of a slope to shelf succession. The succession exhibits progradational followed by aggradational stacking of deltaic cycles that is related to a change in shelf-edge trajectory, and lies within two depositional sequences. Sediment was transferred to the slope via overextension of deltas onto and over the shelf edge, resulting in failure and re-adjustment of local slope gradients. The depositional facies and architecture of the Kookfontein Formation record the change from a bypass- to accretion-dominated margin, which is interpreted to reflect a decrease in sediment transport efficiency as the slope gradient decreased, slope length increased and shelf-edge trajectory rose. During this time the delivery system changed from point-sourced basin-floor fans fed by slope channels to starved basin-floor with sand-rich slope clinoforms. This is an example of a progradational margin in which the younger slope system is interpreted to be of a different style to the older slope system that fed the underlying sand-rich basin floor fans.  相似文献   

Artificial recharge through a thick, heterogeneous unsaturated zone   总被引：2，自引：0，他引：2  

Izbicki JA  Flint AL  Stamos CL 《Ground water》2008,46(3):475-488

Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 x 10(6) m(3) of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 x 10(6) m(3) of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area.  相似文献   

Electoral geography and the social construction of space: The example of the Nazi party in Baden, 1924–1932     

Colin Flint 《GeoJournal》2000,51(3):145-156

This paper makes two contributions towards making a theoretically driven electoral geography a vital component of geography. First, a theoretical framework for the empirical analysis of elections is proposed that views elections as one component of the social construction of space while simultaneously illustrating how space structures electoral behavior. Second, the concepts of a geographic theory of voter mobilization need to be operationalized in such a way that space is an integral component of statistical analysis. The statistical concepts of spatial dependence and spatial heterogeneity are used to include electoral locales and the regionalization of voter mobilization in the analysis. The theoretical framework and statistical operationalization proposed are illustrated by a statistical analysis of the growth of the Nazi party vote in Baden between 1924 and 1932.  相似文献   

Zooplankton in Bays of the Novaya Zemlya Archipelago: Composition,Distribution, and Role in Phytoplankton Grazing and Biosedimentation     

Amelina  A. B.  Drits  A. V.  Sergeeva  V. M.  Soloviyev  K. A.  Belyaev  N. A.  Dara  O. M.  Demidov  A. B.  Flint  M. V. 《Oceanology》2018,58(6):825-837

Oceanology - The zooplankton community in two bays of the eastern coast of the Novaya Zemlya archipelago (Blagopoluchiya Bay and Tsivolki Bay) has been studied for the first time. Copepods of the...  相似文献   

Investigations of the Ecosystem in the Atlantic Sector of Antarctica (Cruise 79 of the R/V Akademik Mstislav Keldysh)     

Morozov  E. G.  Spiridonov  V. A.  Molodtsova  T. N.  Frey  D. I.  Demidova  T. A.  Flint  M. V. 《Oceanology》2020,60(5):721-723

Oceanology - Field works on cruise 79 of the R/V Akademik Mstislav Keldysh aimed at investigating the ecosystems in the Atlantic sector of Antarctica were conducted from January 16 to March 1,...  相似文献   

Biochemical Composition and Energy Content in the Zooplankton of the Kara Sea     

Lobus  N. V.  Flint  M. V.  Flerova  E. A.  Shcheglova  Y. V. 《Oceanology》2020,60(6):778-786

Oceanology - This article presents a data set on ash, proteins, lipids, carbohydrates, chitin, organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) contents, macronutrients ratio (C,...  相似文献