scholarly journals Oceanographic and topographic conditions structure benthic meiofauna communities in the Weddell Sea, Bransfield Strait and Drake Passage (Antarctic)

2018 ◽  
Vol 162 ◽  
pp. 240-256 ◽  
Author(s):  
Gritta Veit-Köhler ◽  
Stephan Durst ◽  
Jan Schuckenbrock ◽  
Freija Hauquier ◽  
Laura Durán Suja ◽  
...  
2020 ◽  
Vol 5 (4) ◽  
pp. 56-68
Author(s):  
N. Yu. Mirzoeva ◽  
N. N. Tereshchenko ◽  
A. A. Paraskiv ◽  
V. Yu. Proskurnin ◽  
E. G. Morozov

Relevance of monitoring heavy metals content in the water of the Atlantic sector of the Antarctic is due to the need for a current assessment of quality of the marine environment for making responsible decisions on the conservation of marine living resources in this unique area of the World Ocean. The aim of the study was to obtain new data on levels and spatial distribution of concentrations of trace elements, mainly heavy metals, in surface water. Sampling of surface seawater was carried out during the Antarctic expedition of the 79th cruise of the RV “Akademik Mstislav Keldysh” at 21 stations in the area of the Drake Passage, the Bransfield Strait, and the Antarctic Sound, as well as in Weddell and Scotia seas. Extracting and concentrating of dissolved form of 13 trace elements (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, and Fe) were performed using sodium diethyldithiocarbamate and carbon tetrachloride (CCl4). The elements were measured by mass spectrometry. Among all trace elements content, only Mo concentration in seawater at 9 stations, located in the Drake Passage, the Bransfield Strait, northern Weddell Sea, and off the southern coast of Tierra del Fuego Island, exceeded 1.2–2.8 times maximum permissible concentration of trace elements in fishery water bodies of the Russian Federation (MPCF). According to international regulatory legal acts, such as “Dutch sheets”, there were single cases of exceeding MPC (maximum permissible concentration under short-term exposure) for Cd and Zn, as well as exceeding TV (target value under chronic exposure) for Cu, Pb, Cd, Zn, Se, and Co at several stations. The research has shown as follows: despite limited anthropogenic pressure on this area of the Southern Ocean, in seawater of some regions of the Atlantic sector of the Antarctic, increased concentrations of several trace elements, inter alia heavy metals, are recorded. Further study of the sources of trace elements intake and the peculiarities of their distribution in seawater of the Atlantic sector of the Antarctic is required in order to account for ongoing processes, take measures for rational management, and provide ecologically acceptable use of natural resources in the Antarctic.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Graeme Eagles ◽  
Hannes Eisermann

AbstractUncertainty about the structure of the Falkland Plateau Basin has long hindered understanding of tectonic evolution in southwest Gondwana. New aeromagnetic data from the basin reveal Jurassic-onset seafloor spreading by motion of a single newly-recognized plate, Skytrain, which also governed continental extension in the Weddell Sea Embayment and possibly further afield in Antarctica. The Skytrain plate resolves a nearly century-old controversy by requiring a South American setting for the Falkland Islands in Gondwana. The Skytrain plate’s later motion provides a unifying context for post-Cambrian wide-angle paleomagnetic rotation, Cretaceous uplift, and post-Permian oblique collision in the Ellsworth Mountains of Antarctica. Further north, the Skytrain plate’s margins built a continuous conjugate ocean to the Weddell Sea in the Falkland Plateau Basin and central Scotia Sea. This ocean rules out venerable correlation-based interpretations for a Pacific margin location and subsequent long-distance translation of the South Georgia microcontinent as the Drake Passage gateway opened.


1994 ◽  
Vol 41 (4) ◽  
pp. 629-641 ◽  
Author(s):  
T. Whitworth ◽  
W.D. Nowlin ◽  
A.H. Orsi ◽  
R.A. Locarnini ◽  
S.G. Smith

Author(s):  
S. P. Levashov ◽  
◽  
N. A. Yakymchuk ◽  
I. N. Korchagin ◽  
V. G. Bakhmutov ◽  
...  

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