• Journal of the korean society of oceanography
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• 제38권1호
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• pp.1-10
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• 2003

A time-series sediment trap was deployed at a depth of 1034 m in the eastern Bransfield Strait from December 25, 1998 to December 24, 1999. Particle fluxes showed large seasonal variation; about 99% of the annual total mass flux (49 g m/sup -2/) was collected during the austral summer and fall (January-March). Settling particles consisted primarily of biogenic silica, organic carbon, calcium carbonate, and lithogenic material. Biogenic silica and lithogenic material predominated settling particles, comprising 36% and 30% of the total mass flux, respectively, followed by organic carbon, 11% and calcium carbonate, merely 0.6%. The annual organic carbon flux was 5.4 g C m/sup -2/ at 1000 m in the eastern Bransfield Strait, which is greater than the central Strait flux. The relatively lower flux of organic carbon in the central Bransfield Strait may be caused by a stronger surface current in this region. Organic carbon flux estimates in the eastern Bransfield Strait are the highest in the Southern Ocean, perhaps because of the fast sinking of fecal pellets, which leads to less decomposition of organic material in the water column. Approximately 5.8% of the organic carbon produced on the surface in the eastern Bransfield Strait is exported down to 1000 m; this percentage exceeds the maximum EF/sub 1000/ values observed in the Atlantic and Southern Oceans. The eastern Bransfield Strait appears to be the most important site of organic carbon export to the deep sea in the Southern Ocean.

• Ocean and Polar Research
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• 제24권2호
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• pp.153-166
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• 2002

Particle fluxes were measured by using time-series sediment traps in the Bransfield Strait from December 27th, 1999 to December 26th, 2000. Total mass fluxes showed distinct seasonal variations with high fluxes in the austral summer and low fluxes in the austral winter at a 678m water depth in the eastern Bransfield Strait, while they were high only in January and fairly low in other months at a 960m water depth in the central Bransfield Strait. The reason that total mass fluxes occurred only in January at a 960m water depth in the central Bransfield Strait seems to be the strong current in the surface waters, which leads to a substantial amount of terrestrial materials and locally produced organic matter being advected away from the mooring site. Total mass fluxes were very high from January to October at a 1678m water depth in the eastern Bransfield Strait, while they were high only in January and February at a 1860m water depth in the central Bransfield Strait. The fact that total mass fluxes were higher at the deep water in the both sites than at the intermediate water depth may reflect that a substantial amount of terrestrial and organic materials are laterally transported by strong tidal current from the shallow environments to the deep basins.

• Ocean and Polar Research
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• 제24권3호
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• pp.301-311
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• 2002

We used diatom and porewater data of two piston cores from the central subbasin and one from the western subbasin in the Bransfield Strait in the northern Antarctic Peninsula to elucidate the depositional mechanism of the layered diatom ooze. The layered diatom ooze is characterized by an abundance of organic carbon, biogenic silica, sulfde sulfur, and lower porewater sulfate concentration. This lack of pore-water sulfate concentration in the diatom ooze interval may reflect development of reducing micro-environment in which bacterially mediated sulfate reduction occurred. The negative relationship between the total organic carbon and sulfate contents, however, indicates that sulfate reduction was partly taking place but does not control organic carbon preservation in this unit. Rather, well-preserved Chaetoceros resting spores in the layered diatom ooze indicate a rapid sedimentation of the diatom as a result of repetitive iceedge blooms on the Bransfield shelf during the cold period (around 2500 yrs BP) when the permanent seaice existed on the shelf, During this period, it is expected that the downslope-flowing cold and dense water was also formed on the Bransfield shelf as a result of sea ice formation, playing an important role for the formation of layered diatom ooze in the Bransfield subbasins.

• 지구물리
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• 제8권4호
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• pp.173-185
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• 2005

This study examines the relationships among sea ice concentration, surface air temperature, surface wind, and SST (Sea Surface Temperature) in Bransfield Strait to understand the climatic characteristics and its related sedimentary process there. In analyses of the monthly data, during the austral autumn (Mar., Apr., and May), the frequency of southeasterlies is correlated positively with the sea ice concentration and negatively with the surface air temperature, whereas that of northwesterlies is reverse. These relationships are explained by the process that the southeasterlies of the cold air from the Antarctic Continent affect the ocean current around Bransfield Strait. And then the ocean current makes the sea ice generated in the Weddell Sea drift into the strait. During the spring (Sep., Oct., and Nov.), sea ice concentration and surface air perature are closely correlated with the frequency of northwesterlies with warm air mass. In the some parts of the northern boundary region, the sea ice concentration in Bransfield Strait is positively correlated with the SST during the autumn and spring. Such relationship may rather propel the sea ice melting in proportion to the sea ice concentration during the autumn.

• 지구물리
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• 제2권4호
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• pp.241-250
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• 1999

남극 브랜스필드 해협에서 획득한 탄성파 자료로부터 다중반사파와 해저면 반사파의 진폭비를 이용하여 해저면 반사계수를 구하였다. 시험 자료처리 결과에 의하면 측점에 따른 심한 변동오차를 감소시키기 위하여 이동평균이 효과적임을 보여준다. 계산된 해저면 반사계수와 해저면 물성에 반영된 지질환경과의 관련성을 분석하였다. 중부 브랜스필드분지 지역에서는 퇴적물의 공급원으로부터의 거리가 멀수록 반사계수가 감소하는 변화양상이 우세하여, 사면 근처에서는 0.12∼0.2 사이, 분지의 중심에서는 0.1∼0.12 사이의 반사계수를 나타낸다. 서부 브랜스필드분지에서 지역적으로 나타나는 빙하침식 지형에서는 반사계수가 0.2∼0.3의 범위 내에서 변하였으며, 확장중심의 화산분출물이 노출된 지역은 0.2 이상의 큰 반사계수를 나타냈다. 또한 지체구조운동에 의해 상승작용을 받은 고지층들이 후기의 빙하침식작용에 의해 해저면에 드러난 지역에서는 해저면 반사계수가 비교적 크게 나타났다.

• Ocean and Polar Research
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• 제23권4호
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• pp.395-400
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• 2001

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait from December 25, 1998 to December 24, 1999. About 99 % of total mass fluxes were observed during the austral summer and fall (January, February, and March). The annual total mass flux was $49.2g\;m^{-2}$. Biogenic materials including biogenic silica, organic matter, and carbonate accounted for about 67% of total particle flux, and lithogenic materials contributed about 29%. Biogenic silica was the most dominant (42% of the total flux) in these components. The next most important biogenic component was organic matter, comprising 24% of total mass flux. Calcium carbonate contributed a small fraction of total mass flux, only 0.6%. The annual organic carbon flux was $5.2g\;C\;m^{-2}$ at 1,034m water depth. The annual primary production was estimated to be $21.6g\;C\;m^{-2}$ at the sediment trap site, which seems to be highly underestimated. About 5.5% of the surface water production of organic carbon sinks below 1,034m water depth.

• Ocean and Polar Research
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• 제25권1호
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• pp.41-52
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• 2003

Sediment trap samples were collected to find out characteristic behaviors of metals in the settling particles by using time-series sediment traps at 678m and 1678m water depths in the Bransfield Strait from December 27th, 1999 to December 26th, 2000. Total mass fluxes at the intermediate water depth (678m water depth) were high in the austral summer and low in the austral winter, whereas at the deep water depth (1678m water depth) they showed high values in both the summer and winter. Total mass fluxes were generally higher in the deep water depth than in the intermediate water depth, which indicates that a substantial amount of sediments are laterally transported by strong currents into the deep basin from the shallow water depths. Aluminium contents also showed large seasonal variations with high values in the winter and low values in the summer. On the contrary, organic carbon contents were high in the summer and low in the winter. Al contents were negatively correlated with organic carbon contents, which may be ascribed that detrital particles are diluted by organic matter produced by phytoplankton in the surface waters. Metals measured in this study exhibited three characteristic behaviors; 1) a positive correlation with Al-Ti, Fe, Mn, V, Co, and Ba, 2) a negative correlation with Al-Cd and Zn, 3) no relationship with Al-Sr, Cu, Cr, Ni. Terrestrial materials may act as a major source fer metals that are positively correlated with Al, and organic matter may be a major source for metals that are negatively correlated with Al. Enrichment factor (EF) of Fe, Mn, Ba, Vi Co, Sr, Cr, and Ni ranged from 0.5 to 1.5, whereas EF of Zn, Cu, and Cd showed much higher values than 1.

• 한국해양학회지
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• 제27권3호
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• pp.250-258
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• 1992

남극 브렌스필드 해협의 표층 수괴 특성을 파악하기 위하여 수온, 염분 및 영양염 류와 더불어 결빙이나 해빙의 영향을 받지 않는 산소 동위원소비를 측정하였다. 염분, 수온, $\delta$/SUP 18/O은 각각 34.0~34.5$\textperthousand$, -0.5~2.1$^{\circ}C$, -0.50~ -0.26$\textperthousand$의 분포 범위 를 보이며, 이들의 지역적 분포는 대체로 해협의 북쪽에 저염, 고온의 해수가 남쪽에 고염, 저온의 해수가 존재한다. T-S diagram은 일정한 경향성이 분산된 결과를 보이는 데, 이는 증발, 강우, 결빙 및 해빙의 복합적인 원인에 의한 것으로 보이며, 염분과 $\delta$/SUP 18/O의 관계로 미루어 증발, 강우에 의한 영향보다는 결빙, 해빙에 의한 영향 이 큰 것으로 나타났다. 영양염의 분포는 해협의 북쪽에서 낮고, 남쪽으로 가면서 높 아지는 분포를 보인다. 해협의 북쪽에 고온, 저염 및 저영양염의 수괴가 분포하는 것 으로 보아 브랜스필드 해협의 북쪽에서 얼음 녹은 물이 해협으로 유입되는 것으로 판 단된다. 또한 N/P 비를 비교하여 보면 해협의 해수는 높은 N/P비(19.4)와 낮은 N/P비 (16.7), 2개의 N/P으로 나뉘어 지는데, 높은 N/P비는 해협의 북쪽에, 낮은 N/P비는 남 쪽에 분포한다. 얼음이 녹으면서 표층해수에서 의 질산염의 농도가 인산염의 농도보다 빨리 감소하며, peak ice 근처에서의 N/P비가 특히 높은 것으로 보고되어 이러한 N/P 비의 분포도 해협의 북쪽에서 유입되는 얼음 녹은 물의 증거가 될 수 있을 것으로 생 각된다. 엽록소 a 분포는 대체로 Weddell Sea쪽에서 남동쪽으로 가면서 증가하며, 영 양염 농도가 낮은 얼음 녹은 물의 유입이 얼룩소 a의 농도를 감소시키는 것으로 사료 된다.

• Ocean and Polar Research
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• 제26권4호
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• pp.607-618
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• 2004

Zooplankton community was surveyed during the Seventh Korea Antarctic Research Program, from 28 December 1993 to 11 January 1994. Zooplankton samples were collected at 40 stations from the waters around the South Shetland Islands with a Bongo net and a MOCNESS. A total of 14 taxa of zooplankton were identified. Zooplankton abundances varied at each station as well as with the sampling gears. Zooplankton abundances were higher in the Western Weddell Sea than those in the Bransfield strait. Zooplankton collected with MOCNESS showed a different vertical distribution depending on its depths at selected stations. Copepods were the major components of zooplankton contributing 72.84% (mesh size $333{\mu}m$) and 68.36% (mesh size $505{\mu}m$) of total zooplankton abundance from the Bongo samples. Salps were the second most abundant group comprising 7.92% $(333{\mu}m)$ and 11.99% $(505{\mu}m)$ of total zooplankton abundance. Euphausiids, chaetognaths, polychaetes, pteropods and ostracods occurred more than 1% of total zooplankton. Copepods were not abundant at stations salps and euphausiids were dominant. Salpa thompsoni, Euphausia superba, Calanoides acutus, Metridia gerlachei and Calanus propinquus were dominant depending on the stations. The hierarchical UPGMA cluster analysis of dissimilarities between sampling stations is displayed with clusters identified similar habitats. Copepods rarely appeared in the clusters 4 and 5, and they appeared a ffw in the cluster 3 (or salps were numerous), while copepods were abundant in the clusters 1 and 2. As in the results of cluster analysis, the distributions of dominant taxa have a well identified correspondence to the geological positions included physical factors.

• Ocean and Polar Research
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• 제23권2호
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• pp.77-95
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• 2001

2000년 1월에 남극 남쉐틀랜드군도(South Shetland Islands) 주변해역에서 수심 200 m 까지 수온, 염분, 영양염, 엽록소, 일차생산력 등을 측정하였다. 표층수온은 남쉐틀랜드군도 북쪽 드레이크해협(Drake Passage)에서 높았고 남극반도 북동해역에서 낮았다. 반대로 염분은 드레이크해협에서 낮았고 남극반도쪽으로 갈수록 점차적으로 증가하여 남극반도 북동해역에서 최고 값을 보였다. 표층해수의 영양염 농도는 대체로 드레이크해협에서 낮은 값을 보였고 남쉐틀랜드군도 인접해역에서 높은 값을 보였다. 엽록소 농도는 드레이크해협과 남극반도 인접해역에서 낮았고 킹조오지섬(King George Island) 북쪽해역에서 높았다. 연구해역은 T-S diagram의 특징적인 형태에 따라 4개 해역으로 구분된다; 드레이크해협, 브랜스필드해협 (Bransfield Strait), 혼합 해역(Mixed zone), 웨델해(Weddell Sea) 해역. 이들 4개 해역들은 각각 특징적인 물리, 화학, 생물학적 특성을 보였다. 식물플랑크톤 생물량은 드레이크해협과 웨델해 해역에서 상대적으로 낮았고 브랜스필드해협과 혼합 해역에서 높았다. 웨델해 해역에서 식물플랑크톤 생물량이 낮은 것은 낮은 수온과 수심 200 m 이상의 깊은 표층혼합 때문이라고 생각되고 드레이크해협 해역에서는 높은 동물플랑크톤 포식압과 낮은 철농도 때문인 것으로 생각된다.