• Title/Summary/Keyword: antarctic research

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Distribution and Vertical Structures of Water Masses around the Antarctic Continental Margin

  • Kim, Seong-Joong;Lee, Bang-Yong
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.277-288
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    • 2005
  • Spatial distribution and vertical structures of water masses around the Antarctic continental margin are described using synthesized hydrographic data. Antarctic Surface Water (AASW) over the shelf regime is distinguished from underlying other water masses by the cut-off salinity, varying from approximately 34.35 to 34.45 around Antarctica. Shelf water, characterized by salinity greater than the cut-off salinity and potential temperature less than $-17^{\circ}C$, is observed on the Ross Sea, off George V Land, off Wilkes Land, the Amery Basin, and the Weddell Sea, but in some shelves AASW occupies the entire shelf. Lower Circumpolar Deep Water is present everywhere around the Antarctic oceanic regime and in some places it mixes with Shelf Water, producing Antarctic Slope Front Water (ASFW). ASFW, characterized by potential temperature less than about $0^{\circ}C$ and greater than $-17^{\circ}C$, and salinity greater than the cut-off salinity, is found everywhere around Antarctica except in the Bellingshausen-Amundsen sector. The presence of different water masses over the Antarctic shelves and shelf edges produces mainly three types of water mass stratifications: no significant meridional property gradient in the Bellingshausen and Amundsen Seas, single property gradient where ASFW presents, and a V-shaped front where Shelf Water exists.

An Fundamental Study of on Freezing Characteristics of Antarctic Soil (남극 대륙기지 건설지에서 채취한 흙시료의 동결특성에 관한 기초연구)

  • Hong, Seung-Seo;Kim, Young-Seok;Bae, Gyu-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1030-1038
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    • 2010
  • In order to design and construction of the Antarctic Continental Station at the Terra Nova Bay in the East Antarctic, ground characteristics for soil samples taken from the Antarctic. A series of laboratory tests were performed to investigate the variations of the thermal conductivity, the unfrozen water content according to the temperature change of the soil taken from the Antarctic. The temperature were low down below zero.

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Lichen Flora around the Korean Antarctic Scientific Station, King George Island, Antarctic

  • Kim, Ji-Hee;Ahn, In-Young;Hong, Soon-Gyu;Andreev, Mikhail;Lim, Kwang-Mi;Oh, Mi-Jin;Koh, Young-Jin;Hur, Jae-Seoun
    • Journal of Microbiology
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    • v.44 no.5
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    • pp.480-491
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    • 2006
  • As part of the long-term monitoring projects on Antarctic terrestrial vegetation in relation to global climate change, a lichen floristical survey was conducted around the Korean Antarctic Station (King Sejong Station), which is located on Barton Peninsula, King George Island, in January and February of 2006. Two hundred and twenty-five lichen specimens were collected and sixty-two lichen species in 38 genera were identified by morphological characteristics, chemical constituents, TLC analysis and ITS nucleotide sequence analysis.

Development of Antarctic Treaty System and Roles and Prospects of the Committee for Environmental Protection (남극조약 체제의 발전과정과 환경보호위원회의 역할과 전망)

  • Kim, Ji Hee
    • Ocean and Polar Research
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    • v.40 no.4
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    • pp.259-270
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    • 2018
  • The purpose of this study is to provide information to understand the context of the Antarctic Treaty System by looking back on its development process. It also aims to review the roles and activities of the CEP in the System in order to support the improvement of our Antarctic science policy. This study considered the developmental histories of independent conventions for Antarctic conservation and Protocol on Environmental Protection to the Antarctic Treaty under the system. CEP, established in accordance with the Protocol, has expanded its roles in the ATCM under the circumstances of climate change and increasing human activities in the treaty area. I examined CEP's functions, relationships with formal observers, and its activities along with CCRWP. In addition, I have estimated the contribution of the Parties to the CEP based on the documents submitted by the Parties. The leading Parties of the System have strengthened their initiatives to expand contributions to CEP with their output based on national Antarctic Program. However, Korea has not been able to take initiatives in the System even though Korea has invested considerable resources in its Antarctic program. To strengthen Korea's capability to instigate initiatives in the system, I suggest the following approaches: Firstly, Korea should improve its Antarctic science policy based on the newly established CEP five-year work plan; Secondly, Korea should organize a long-standing expert group to focus on Antarctic environmental policy and related scientific information; finally, Korea should intensify its collaboration with other Parties in developing Antarctic environmental priority issues.

Total Mercury Contents of Antarctic Toothfish Dissostichus mawsoni Caught in the Antarctic Sea

  • Son, Kwang-Tae;Kwon, Ji-Young;Jo, Mi-Ra;Yoon, Minchul;Song, Ki-Cheol;Choi, Woo-Seok;Yeon, In-Ja;Kim, Ji-Hoe;Lee, Tae Seek
    • Fisheries and Aquatic Sciences
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    • v.17 no.4
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    • pp.427-431
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    • 2014
  • Mercury is an element of special concern for human health. Measurements of total mercury levels in fish have been taken into consideration to assess risk. In this study, the Antarctic toothfish Dissostichus mawsoni was evaluated as a potential safe food source through measurement of total mercury contents. Total mercury concentrations in Antarctic toothfish ranged from $0.101{\pm}0.047mg/kg$ to $0.139{\pm}0.075mg/kg$. The total mercury concentration was significantly correlated with macroscopic values including total fish length, weight, gonadosomatic index, and maturity (P < 0.01 or 0.05). Furthermore, according to the risk assessment, the total mercury body exposure rate from Antarctic toothfish ranged from 2.125% to 2.847% of the Provisional Tolerable Weekly Intake. Therefore, the Antarctic toothfish could be used as a potential safe seafood source.

Current Status of Antarctic Environments and Resources

  • Park, Paul-Kilho;Sutton, Holly J.;Kim, Su-Am
    • Journal of the korean society of oceanography
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    • v.33 no.3
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    • pp.123-135
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    • 1998
  • Cooperative scientific research in Antarctic has been successful since the International Geophysical Year 1957/1958. Presently, 43 nations have joined the Antarctic Treaty as consultative parties or acceding states, and other treaties and agreements have evolved to conserve the integrity and to manage the resources of the Antarctic ecosystem. Although yet to be designated, tourism areas in Antarctica are under consideration. Due to its remoteness and vast magnitude, Antarctica's science is slowly emerging. Satellite technology has enabled observation of the progression of the ozone hole above Antarctica. Mineral exploitation has yet to take place, as has the transport of Antarctic icebergs to some arid nations. On the other hand, both seal and whale exploitations have occurred, devastating these populations. The lessons learned from past human greed are used to design krill and squid fisheries, though the life histories of these organisms are yet to be adequately understood. An ecosystem approach to managing Antarctic resource exploitation is essential. Procuring the needed logistics to do so is daunting, requiring the highest degree of international cooperation and educational outreach to nurture the needed effective scientific and engineering talent, both natural and social.

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Krill and Currents-Physical and Biological Interactions Influencing the Distribution of Euphausia superba

  • Nicol, Stephen
    • Ocean and Polar Research
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    • v.25 no.4
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    • pp.633-644
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    • 2003
  • The distribution and abundance of Antarctic krill (Euphausia superba), particularly in the South Atlantic, has traditionally been viewed as primarily determined by the flow of the Antarctic Circumpolar Current. Krill are viewed as being particles on a conveyor belt that carries them around the Antarctic continent resulting in a single circumpolar population. The evidence to support this viewpoint is largely circumstantial and there is very little direct evidence available of krill being moved by the currents-krill flux. There is also considerable biological and physical evidence which suggests that other factors may play a dominant role in the life history and distribution of krill. This review examines the evidence fur krill flux and also examines evidence that does not accord with this theory. The management implications of assuming krill flux are outlined and some lines for future research are suggested.

Possible Roles of Antarctic Krill Proteases for Skin Regeneration

  • Lee, Sung-Gu;Koh, Hye-Yeon;Lee, Hong-Kum;Yim, Joung-Han
    • Ocean and Polar Research
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    • v.30 no.4
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    • pp.467-472
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    • 2008
  • Antarctic krill has a strong proteolytic enzyme system, which comes from a combination of several proteases. This powerful activity can be easily detected by krill's superior post mortem autolysis. Mammalian skin consists of epidermis and dermal connective tissue, and functions as a barrier against threatening environments. A clot in a wound site of the skin should be removed for successful skin regeneration. Epithelial cells secrete proteases to dissolve the clot. In previous studies Antarctic krill proteases were purified and characterized. The proteolytic enzymes from Antarctic krill showed higher activity than mammalian enzymes. It has been suggested that these krill clean up the necrotic skin wound to induce a natural healing ability. The enzymes exhibited additional possibilities for several other biomedical applications, including dental plaque controlling agent and healing agent for corneal alkali burn. Considering that these versatile activities come from a mixture of several enzymes, discovering other proteolytic enzymes could be another feasible way to enhance the activity if they can be used together with krill enzymes. Molecular cloning of the krill proteases should be carried out to study and develop the applications. This review introduces possible roles of the unique Antarctic krill proteases, with basic information and suggestion for the development of an application to skin regeneration.

Expressed Sequence Tag Analysis of Antarctic Hairgrass Deschampsia antarctica from King George Island, Antarctica

  • Lee, Hyoungseok;Cho, Hyun Hee;Kim, Il-Chan;Yim, Joung Han;Lee, Hong Kum;Lee, Yoo Kyung
    • Molecules and Cells
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    • v.25 no.2
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    • pp.258-264
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    • 2008
  • Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

Origin of Spherule Samples Recovered from Antarctic Ice Sheet-Terrestrial or Extraterrestrial?

  • Sekimoto, Shun;Kobayashi, Takayuki;Takamiya, Koichi;Ebihara, Mitsuru;Shibata, Seiichi
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.293-298
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    • 2016
  • Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0.017% to 7%, respectively. A detectable iridium content of 0.84 mg/kg was found in only one spherule, which was judged to be extraterrestrial in origin. A comparison of elemental compositions of the Antarctic spherules analyzed in this study with those of deep-sea sediment spherules and those of terrestrial materials revealed that most of the Antarctic spherules except for the sample in which iridium was detected could not be identified as extraterrestrial in origin.