Variation of Geostrophic Circulation off the Antarctic Peninsula and in the Southwest Scotia Sea, 1975–1985

1988 ◽  
pp. 81-91 ◽  
Author(s):  
M. Stein
Keyword(s):  
Antarctic Peninsula ◽  
Scotia Sea ◽  
The Antarctic

scholarly journals Glacier Fluctuations in George VI Sound Area, West Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 345 ◽  
Author(s):  
C.M. Clapperton ◽  
D.E. Sugden
Keyword(s):  
Antarctic Peninsula ◽  
Ice Age ◽  
List Type ◽  
West Antarctica ◽  
Ice Shelf ◽  
Scotia Sea ◽  
Field Evidence ◽  
Glacial Chronology ◽  
History Of ◽  
The Antarctic

George VI Sound lies between Alexander Island and the Antarctic Peninsula and is over 20 km wide and 500 km long. At present an ice shelf fills the sound and is nourished largely by ice from the Antarctic Peninsula which flows across the sound to ground against the coast of Alexander Island. Ice-free areas, comprising small nunataks and larger massifs, fringe both sides of the sound and contain evidence of the former glacial history of the area. This paper describes the field evidence in detail and uses geomorphological and sedimentary analyses to put forward a relative glacial chronology, constrained by two absolute dates. The chronology distinguishes: (1) a maximum state during which all ice-free areas were submerged by ice flowing into George VI Sound from both the Antarctic Peninsula and Alexander Island and thence along the sound as an ice stream. This occurred in the late Wisconsin and followed an interstadial or interglacial when George VI Sound was free of an ice shelf. (2) a valley-based stadial during overall deglaciation represented by pronounced marginal moraines on Alexander Island. (3) deglaciation to a stage where there was less landbased ice on Alexander Island than today. At this stage isostatic recovery was incomplete, relative sealevel was higher, and George VI Ice Shelf penetrated further into embayments on Alexander Island than at present. (4) probable disappearance of George VI Ice Shelf by 6.5 14C ka BP. (5) neoglacial readvance of local glaciers on Alexander Island to form three closely spaced terminal moraines and the growth of a new George VI Ice Shelf which was again more extensive than at present. (6) subsequent oscillations of both smaller Alexander Island glaciers and George VI Ice Shelf probably during the Little Ice Age. These fluctuations are similar to those in other sub-Antarctic Islands in the Scotia Sea and also in southern Chile.

scholarly journals Fe sources and transport from the Antarctic Peninsula shelf to the southern Scotia Sea

2019 ◽  
Vol 150 ◽  
pp. 103060 ◽  
Author(s):  
Mingshun Jiang ◽  
Christopher I. Measures ◽  
Katherine A. Barbeau ◽  
Matthew A. Charette ◽  
Sarah T. Gille ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Scotia Sea ◽  
The Antarctic

Testing early life connectivity using otolith chemistry and particle-tracking simulations

2010 ◽  
Vol 67 (8) ◽  
pp. 1303-1315 ◽  
Author(s):  
Julian Ashford ◽  
Mario La Mesa ◽  
Bettina A. Fach ◽  
Christopher Jones ◽  
Inigo Everson
Keyword(s):  
Antarctic Peninsula ◽  
Early Life ◽  
Large Scale ◽  
Circulation Model ◽  
Model Material ◽  
Otolith Chemistry ◽  
Larval Phase ◽  
Scotia Sea ◽  
South Georgia ◽  
The Antarctic

We measured the otolith chemistry of adult Scotia Sea icefish ( Chaenocephalus aceratus ), a species with a long pelagic larval phase, along the Antarctic Circumpolar Current (ACC) and compared the chemistry with simulated particle transport using a circulation model. Material laid down in otolith nuclei during early life showed (i) strong heterogeneity between the Antarctic Peninsula and South Georgia consistent with a population boundary, (ii) evidence of finer-scale heterogeneity between sampling areas on the Antarctic Peninsula, and (iii) similarity between the eastern and northern shelves of South Georgia, indicating a single, self-recruiting population there. Consistent with the otolith chemistry, simulations of the large-scale circulation predicted that particles released at depths of 100–300 m on the Antarctic Peninsula shelf during spring, corresponding to hatching of icefish larvae from benthic nests, are transported in the southern ACC, missing South Georgia but following trajectories along the southern Scotia Ridge instead. These results suggest that the timing of release and position of early life stages in the water column substantially influence the direction and extent of connectivity. Used in complement, the two techniques promise an innovative approach for generating and testing predictions to resolve early dispersal and connectivity of populations related to the physical circulation of oceanic systems.

scholarly journals Copepods, hydromedusae and siphonophores: Diversity and distribution in the Gerlache Strait, Antarctic Peninsula

2021 ◽  
Vol 50 (SuplEsp) ◽  
pp. 169-186
Author(s):  
Edgar Dorado ◽  
Cristina Cedeño
Keyword(s):  
Antarctic Peninsula ◽  
Weddell Sea ◽  
Dominant Form ◽  
Scotia Sea ◽  
Frequent Species ◽  
Bellingshausen Sea ◽  
Antarctic Expedition ◽  
The Antarctic ◽  
Oceanographic Conditions

Project Biodiversity and oceanographic conditions of the strait of Gerlache “Biogerlache-Antarctica”, aims to carry out the characterization of the Antarctic fauna of the strait, generating new contributions to the biological inventories of Antarctica. Present work focuses on the biodiversity of the zooplanktonic community, specifically on copepods, hydromedusae and siphonophorae collected during the III Antarctic Expedition of Colombia “Admiral Padilla” (2016-2017). Sampling was carried out in seven oceanographic stations located along the Gerlache strait, with vertical trawls between the maximum depth of the station and the surface. 4100 organisms belonging to 38 species of the phylum Arthropoda (Orders Calanoid and Cyclopoid) and 10 species of the phylum Cnidaria (Subclasses Hydroidolina and Trachylina) were identified. Copepods families with the greatest richness of genera are Aetideidae and Metridinidae, with Metridia gerlachei, Chiridius polaris and Gaetanus tenuispinosus being frequent species in more than 50 % of the stations. Identified species are common to the Antarctic Peninsula (Bellingshausen Sea, Scotia Sea and the Weddell Sea), also the range of four copepods are extended for the epipelagic and mesopelagic waters of the Gerlache Strait. Other frequent species are the hydromedusae Arctapodema sp. and Solmundella bitentaculata and the siphonophores Dimophyes arctica and Diphyes antarctica, the latter being collected in both polygastric and eudoxic forms (the dominant form in all stations).

A Discussion on volcanism and the structure of the Earth - The evolution of the Scotia Ridge and Scotia Sea

1972 ◽  
Vol 271 (1213) ◽  
pp. 151-183 ◽  
Keyword(s):  
South America ◽  
Antarctic Peninsula ◽  
Weddell Sea ◽  
East Antarctica ◽  
The South ◽  
Scotia Sea ◽  
South Georgia ◽  
Scotia Ridge ◽  
Magnetic Lineations ◽  
The Antarctic

Marine geophysical surveys over the Scotia Ridge show it to be composed of blocks mainly of continental origin. Major structures found on the blocks are in many cases truncated at block margins and their existence is also inconsistent with the present isolated situation of the blocks. The evidence suggests post-Upper Cretaceous fragmentation of a continuous continental area. Complementary marine geomagnetic studies over the deep water of the Scotia Sea have dated two areas as younger than 22 million years (Ma) and have indicated the direction of spreading in others. A model of present plate motions, based on the magnetic anomalies, explains the active volcanism of the South Sandwich Islands as being caused by consumption of Atlantic crust at the associated trench at a rate of 5.5 cm/year for the past 7 to 8 Ma at least. An Upper Tertiary episode of plate consumption at 5 cm/year at the South Shetland trench, suggested by the magnetic lineations, with a secondary slow extensional widening of Bransfield Strait is used to explain similarly the contemporaneous volcanism of the South Shetland Is. Making the reasonable assumption of a Tertiary formation of the undated parts of the Scotia Sea by spreading in the directions indicated by the magnetic lineations, a tentative reconstruction of the component blocks of the Scotia Ridge is made. The attempt is only partly successful in matching structural patterns across adjacent margins of reconstructed blocks, South Georgia being most obviously wrongly situated. It is suggested that the misfits result from minor errors in the initial assumptions and the modification of structures during fragmentation and drift. South Georgia may have formed on the Atlantic rather than the Pacific side of the compact continental region which is thought to have joined South America and west Antarctica for much of the Mesozoic at least. A Gondwanaland reconstruction is presented which is consistent with the Scotia Ridge reconstruction, in which the Antarctic Peninsula lies alongside the Caird Coast of east Antarctica. Upon break-up of Gondwanaland, the Antarctic Peninsula remained rigidly attached to South America, east Antarctica rotating clockwise to open the Weddell Sea, until early Tertiary times when the Peninsula transferred to east Antarctica which continued rotating clockwise to open the Scotia Sea.

scholarly journals Glacier Fluctuations in George VI Sound Area, West Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 345-345
Author(s):  
C.M. Clapperton ◽  
D.E. Sugden
Keyword(s):  
Antarctic Peninsula ◽  
Ice Age ◽  
List Type ◽  
West Antarctica ◽  
Ice Shelf ◽  
Scotia Sea ◽  
Field Evidence ◽  
Glacial Chronology ◽  
History Of ◽  
The Antarctic

George VI Sound lies between Alexander Island and the Antarctic Peninsula and is over 20 km wide and 500 km long. At present an ice shelf fills the sound and is nourished largely by ice from the Antarctic Peninsula which flows across the sound to ground against the coast of Alexander Island. Ice-free areas, comprising small nunataks and larger massifs, fringe both sides of the sound and contain evidence of the former glacial history of the area. This paper describes the field evidence in detail and uses geomorphological and sedimentary analyses to put forward a relative glacial chronology, constrained by two absolute dates.The chronology distinguishes: (1) a maximum state during which all ice-free areas were submerged by ice flowing into George VI Sound from both the Antarctic Peninsula and Alexander Island and thence along the sound as an ice stream. This occurred in the late Wisconsin and followed an interstadial or interglacial when George VI Sound was free of an ice shelf.(2) a valley-based stadial during overall deglaciation represented by pronounced marginal moraines on Alexander Island.(3) deglaciation to a stage where there was less landbased ice on Alexander Island than today. At this stage isostatic recovery was incomplete, relative sealevel was higher, and George VI Ice Shelf penetrated further into embayments on Alexander Island than at present.(4) probable disappearance of George VI Ice Shelf by 6.5 14C ka BP.(5) neoglacial readvance of local glaciers on Alexander Island to form three closely spaced terminal moraines and the growth of a new George VI Ice Shelf which was again more extensive than at present.(6) subsequent oscillations of both smaller Alexander Island glaciers and George VI Ice Shelf probably during the Little Ice Age. These fluctuations are similar to those in other sub-Antarctic Islands in the Scotia Sea and also in southern Chile.

scholarly journals Natural iron enrichment around the Antarctic Peninsula in the Southern Ocean

2010 ◽  
Vol 7 (1) ◽  
pp. 11-25 ◽  
Author(s):  
M. V. Ardelan ◽  
O. Holm-Hansen ◽  
C. D. Hewes ◽  
C. S. Reiss ◽  
N. S. Silva ◽  
...  
Keyword(s):  
Primary Production ◽  
Antarctic Peninsula ◽  
Weddell Sea ◽  
South Shetland Islands ◽  
Scotia Sea ◽  
Shetland Islands ◽  
Iron Enrichment ◽  
Bransfield Strait ◽  
Natural Iron ◽  
The Antarctic

Abstract. As part of the US-AMLR program in January-February of 2006, 99 stations in the South Shetland Islands-Antarctic Peninsula region were sampled to understand the variability in hydrographic and biological properties related to the abundance and distribution of krill in this area. Concentrations of dissolved iron (DFe) and total acid-leachable iron (TaLFe) were measured in the upper 150 m at 16 of these stations (both coastal and pelagic waters) to better resolve the factors limiting primary production in this area and in downstream waters of the Scotia Sea. The concentrations of DFe and TaLFe in the upper mixed layer (UML) were relatively high in Weddell Sea Shelf Waters (~0.6 nM and 15 nM, respectively) and low in Drake Passage waters (~0.2 nM and 0.9 nM, respectively). In the Bransfield Strait, representing a mixture of waters from the Weddell Sea and the Antarctic Circumpolar Current (ACC), concentrations of DFe were ~0.4 nM and of TaLFe ~1.7 nM. The highest concentrations of DFe and TaLFe in the UML were found at shallow coastal stations close to Livingston Island (~1.6 nM and 100 nM, respectively). The ratio of TaLFe:DFe varied with the distance to land: ~45 at the shallow coastal stations, ~15 in the high-salinity waters of Bransfield Strait, and ~4 in ACC waters. Concentrations of DFe increased slightly with depth in the water column, while that of TaLFe did not show any consistent trend with depth. Our Fe data are discussed in regard to the hydrography and water circulation patterns in the study area, and with the hypothesis that the relatively high rates of primary production in the central regions of the Scotia Sea are partially sustained by natural iron enrichment resulting from a northeasterly flow of iron-rich coastal waters originating in the South Shetland Islands-Antarctic Peninsula region.

Holocene ice fluctuations on Brabant Island, Antarctic Peninsula

1989 ◽  
Vol 1 (2) ◽  
pp. 165-166 ◽  
Author(s):  
J.D. Hansom ◽  
C.P. Flint
Keyword(s):  
Antarctic Peninsula ◽  
Late Quaternary ◽  
Ice Sheets ◽  
West Antarctica ◽  
Scotia Sea ◽  
Glacial Chronology ◽  
Subantarctic Islands ◽  
History Of ◽  
Quaternary History ◽  
The Antarctic

Recent geomorphological research in the ice-free areas of West Antarctica and the subantarctic islands has begun to provide an outline glacial chronology that helps our understanding of the late Quaternary history of ice sheets. However, there is a need for detailed studies of the glacial history of the Antarctic Peninsula area and its offshore islands before a general chronology can be fully reliable. In particular, evidence of Neoglacial glacial fluctuations in the area are imperfectly known in spite of work by Sugden & Clapperton (1977) on island groups in the Scotia Sea, Clapperton et al. (1978) on South Georgiaand Clapperton & Sugden (1982) on Alexander Island. The aim of this note is to present data relating to Holocene glacier fluctuations from the hitherto unstuded Brabant Island (64°15′S, 62°3′W).

scholarly journals Krill transport in the Scotia Sea and environs

1998 ◽  
Vol 10 (4) ◽  
pp. 406-415 ◽  
Author(s):  
Eileen E. Hofmann ◽  
John M. Klinck ◽  
Ricardo A. Locarnini ◽  
Bettina Fach ◽  
Eugene Murphy
Keyword(s):  
Flow Field ◽  
Antarctic Peninsula ◽  
Antarctic Circumpolar Current ◽  
Large Scale ◽  
Scotia Sea ◽  
South Georgia ◽  
Composite Flow ◽  
Large Scale Flow ◽  
Circumpolar Current ◽  
The Antarctic

Historical observations of the large-scale flow and frontal structure of the Antarctic Circumpolar Current in the Scotia Sea region were combined with the wind-induced surface Ekman transport to produce a composite flow field. This was used with a Lagrangian model to investigate transport of Antarctic krill. Particle displacements from known krill spawning areas that result from surface Ekman drift, a composite large-scale flow, and the combination of the two were calculated. Surface Ekman drift alone only transports particles a few kilometres over the 150-day krill larval development time. The large-scale composite flow moves particles several hundreds of kilometres over the same time, suggesting this is the primary transport mechanism. An important contribution of the surface Ekman drift on particles released along the continental shelf break west of the Antarctic Peninsula is moving them north-northeast into the high-speed core of the southern Antarctic Circumpolar Current Front, which then transports the particles to South Georgia in about 140–160 days. Similar particle displacement calculations using surface flow fields obtained from the Fine Resolution Antarctic Model do not show overall transport from the Antarctic Peninsula to South Georgia due to the inaccurate position of the southern Antarctic Circumpolar Current Front in the simulated circulation fields. The particle transit times obtained with the composite large-scale flow field are consistent with regional abundances of larval krill developmental stages collected in the Scotia Sea. These results strongly suggest that krill populations west of the Antarctic Peninsula provide the source for the krill populations found around South Georgia.

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