• 한국해양학회지
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• v.30 no.4
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• pp.302-319
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• 1995

The geochemical properties, sedimentation rates, foraminiferal distributions, and oxygen and carbon isotope records of sediment from Cores S-2 and S-19 were studied to investigate late Holocene paleoceanographic and paleoclimatic changes of the admiralty and Maxwell Bay, King George Island, Antarctica. Total organic carbon contents increased from the lower part to the upper part of Cores S-2 and S-19, whereas calcium carbonate contents decreased from the lower part to the upper part of Cores S-2 and s-19,whereas calcium carbonate contents decreased from the lower part to the upper part of Cores S-2 and S-19. Twenty-seven foraminiferal species were identified, and Globocassidurina biora was mostly a bundant in sediment samples. The sedimentation rates ranged from 24 cm/kyr to 237 cm/kyr based on /SUP 14/C-age dating of G. biora. The sedimentation rates increased rapidly in the upper part of the Cores. б/SUP 18/O values ranged from 0.3% to 6.2% and б/SUP 13/C values ranged from -3.0% to 0.0% with several fluctuations of the values. The lowest part of Core S-2, at 128 cmbsf in depth, had a /SUP 14/C-age of 3,100${\pm}$60 yr B.P. and the lowest part of Core S-19, at 230 cmbsf in depth, of 7,400${\pm}$ yr B.P. The results of geochemical and sedimentological analyses of the core sediments suggested five stages of paleoceanographic and paleoclimatic changes as follows: war,-cold stage of 7,500∼6,500 yr B.P., cold stage of 6,500∼3,600 yr B.P., cold-warm stage of 3,600∼2,770 yr B.P., warm stage of 2,770∼2,380 yr B.P. and cold-warm stage of 2,380∼2,100 yr B.P.

• Journal of the Mineralogical Society of Korea
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• v.30 no.1
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• pp.21-29
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• 2017

Surface soils on Barton Peninsula, King George Island, West Antarctica were investigated to acquire the mineralogical and geochemical data of soil in Antarctica. Multiline of techniques for example, X-ray diffraction (XRD), transmission electron microscopy (TEM)-electron energy loss spectroscopy (EELS), and wet chemistry analysis were performed to measure the composition of clay minerals, Fe-oxidation states, cation exchange capacity, and total cation concentration. Various minerals in sediments such as smectite, illite, chlorite, kaolinite, quartz and plagioclase were identified by XRD. Fe-oxidation states of bulk soils showed 20-40% of Fe(II) which would be ascribed to the reduction of Fe in clays as well as Fe-bearing minerals. Moreover, redox states of Fe in smectite structure was a ~57% of Fe(III) consistent to the values for the bulk soils. The cation exchange capacity of bulk soils ranged from 100 to 300 meq/kg and differences were not significantly measured for the sampling locations. Total cations (Mg, K, Na, Al, Fe) of bulk soils varies, contrast to the heavy metals (Co, Ni, Cu, Zn, Mn). These results suggested that composition of bed rocks influenced the distribution of elements in soil environments and soils containing clay compositions may went through the bio/geochemical alteration.

• Geophysics and Geophysical Exploration
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• v.15 no.3
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• pp.144-149
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• 2012

Korea Polar Research Institute (KOPRI) has successfully installed two autonomous very broadband three-component seismic stations at the King George Island (KGI), Antarctica, during the 24th KOPRI Antarctic Summer Expedition (2010 ~ 2011). The seismic observation system is originally designed by the Incorporated Research Institutions for Seismology Program for Array Seismic Studies of the Continental Lithosphere Instrument Center, which is fully compatible with the Polar Earth Observing Network seismic system. The installation is to achieve the following major goals: 1. Monitoring local earthquakes and icequakes in and around the KGI, 2. Validating the robustness of seismic system operation under harsh environment. For further intensive studies, we plan to move and install them adding a couple more stations at ice shelf system, e.g., Larsen Ice Shelf System, Antarctica, in 2013 to figure out ice dynamics and physical interaction between lithosphere and cryosphere. In this article, we evaluate seismic station performance and characteristics by examining ambient noise, and provide operational system information such as frequency response and State-Of-Health information.

• Ocean and Polar Research
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• v.26 no.1
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• pp.23-32
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• 2004

As a baseline survey for long-term monitoring on environmental change around the Antarctic King Sejong Station, distribution pattern of Deschampsia antarctica Desv., a flowering plant newly colonized were investigated qualitatively and quantitatively in both austral summer 2002 and 2003. Dispersal of the seeds and vegetative leaves by skuas might lead to the colonization into this area from neighbors in Maxwell Bay. The pioneer populations were observed around ponds and a stream of the Sejong Point in January 2002, and the maximum dispersal area was four times expanded after a year. Most of the populations were formed on the stable and well-drained substrate, which consisted of moss carpet of Sanionia georgico-uncinata (65%) and pebbles (25%), while only a few young individuals were observed on the unstable and watertight silt-sandy area. Especially, S. georgico-uncinata was being effectively utilized as their primary substrate with the soft, coarse and water-contained leaves. Also the perennial mature plants of D. antarctica were mainly formed on the moss carpet rather than pebbles. A few individuals were grown on other mosses of Polytrichastrum alpinum, Bryum pseudotriquetrum, Pohlia cruda, and Conostomum magellanicum and on a liverwort of Cephaloziella varians. We expect that dispersal of D. antarctica and the following succession to grass field will be countinuously and dynamically proceeded in this area, with the characteristics of ecological niche against the initial moss populations, on the similar continuity of environmental conditions. The continuous observations are needed with establishment of database on environmental change of micro-habitats, e.g. the water content and nutrients of soil and the underground temperature and permafrost.

• Ocean and Polar Research
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• v.23 no.2
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• pp.97-107
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• 2001

The Sejong Formation of Late Paleocene to Eocene is a lower volcaniclastic sequence unconformably overlain by upper volcanic sequence, and distributed along the southern and southeastern cliffs of the Barton Peninsula. The Sejong Formation is divided into five sedimentary facies; disorganized matrix-supported conglomerate (Facies A), disorganized clast-supported conglomerate (Facies B), stratified clast-supported conglomerate (Facies C), thin-bedded sandstone (Facies D), and lapilli tuff (Facies E), based on sedimentary textures, primary sedimentary structures and bed geometries. Individual sedimentary facies is characterized by distinct sedimentary process such as gravel-bearing mudflows or muddy debris flows (Facies A), cohesionless debris flows (Facies B),unconfined or poorly confined hyperconcentrated flood flows and sheet floods (Facies C), subordinate streamflows (Facies D), and pyroclastic flows (Facies E). Deposition of the Sejong Formation was closely related to volcanic activity which occurred around the sedimentary basin. Four different phases of sediment filling were identified from constituting sedimentary facies. Thick conglomerate and sandstone were deposited during inter-eruptive phases (stages 1, 3 and 4), whereas lapilli tuff was formed by pyroclastic flows during active volcanism (stage 2). These records indicate that active volcanism occurred around the Barton Peninsula during Late Paleocene to Eocene.

• Ocean and Polar Research
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• v.23 no.1
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• pp.11-21
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• 2001

K-Ar ages of the altered rocks from the Barton Peninsula are belows; altered tuffaceous andesite from southwestern part is 42 Ma, altered rocks contacted with quartz vein from southern part are 28 and 33 Ma, and advanced argillic altered andesite from northeastern part are 33 and 35 Ma. Those K-Ar ages are 10 My younger than granitic rocks of the Barton Peninsula. Hydothermal alteration of the Barton Peninsula was originated from mixing of magmatic water from parent magma of granitic rocks with meteoric water. The Al content in the hostrock is relatively constant during hydrothermal alteration, on the contrary the Mg content is in proportion to total alkali. The variation of total alkali and Mg contents in hydrothermal alteration indicates that those elements was washed out during hydrothermal alteration. The sequences of hydrothermal alteration of the Barton Peninsula is chloritization of amphiboles, sericitization of feldspars and kaolitization of sericite.

• ALGAE
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• v.35 no.1
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• pp.17-32
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• 2020

Asterochloris is one of the most common genera of lichen phycobionts in Trebouxiophyceae. Asterochloris phycobionts associated with the lichenized fungi Cladonia and Stereocaulon in King George Island (Antarctica) and Morro Chico (Chile), were isolated and then used to establish clonal cultures. To understand the phylogenetic relationships and species diversity of Antarctic Asterochloris species, molecular and morphological data were analyzed by using three microscopy techniques (light, confocal laser and transmission electron) and a multi-locus phylogeny with data from the nuclear-encoded internal transcribed spacer (ITS) rDNA and the actin and plastid-encoded ribulose bisphosphate carboxylase large chain (rbcL) coding genes. Morphological data of three Antarctic strains showed significant species-specific features in chloroplast while molecular data segregated the taxa into distinct three clades as well. Each species had unique molecular signatures that could be found in secondary structures of the ITS1 and ITS2. The species diversity of Antarctic Asterochloris was represented by six taxa, namely, A. glomerata, A. italiana, A. sejongensis, and three new species (A. antarctica, A. pseudoirregularis, A. stereocaulonicola).

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.337-339
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• 2017

Here we report the draft genome sequence of the Caballeronia sordidicola strain PAMC 26633, isolated from Psoroma species, a lichen material from Barton Peninsula, King George Island in Antarctica. As we have observed in previous genomic studies in the genus Caballeronia from polar lichen, draft genomic sequences of PAMC 26633 had an assortment of genes of ecological importance and of biotechnical potentials, which include diverse metabolic genes for carbohydrates, amino acids, and genes for nitrogen/sulfur metabolisms, stress responses, membrane transporters, antibiotic resistance, and heavy metal resistance. CRISPR genes and sequences were not found and there were some phage remnants and transposons.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.64-64
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• 1995

Cholesteryl Ester Transfer Protein (CETP) mediates the transfer of cholesterol ester and triglyceride between high-density lipoprotein (HDL) and other low-density lipoproteins, therefore, it might influence HDL levels. The levels of HDL is closely related to the atherogenic diseases in human and there were several reports that the trasgenic mice expressing CETP had much worse atherosclerosis than non-expressing control one. Therefore, selective inhibitors of CETP have the potential to be used as antiatherosclerotic agents. Continued screening for potent inhibitors of CETP led to the isolation of Suberitenone B from marine sponge. Suberitenone B, sesterterpenoids of a new skeletal class have been isolated from the sponge Suberites sp. collected from King George Island the Antartic. The structure of the metabolite has been determined by NMR experiments and chemical methods.

• Atmosphere
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• v.16 no.2
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• pp.111-124
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• 2006

This study examines seasonal variability of the surface energy balance at the King Sejong Station, Antarctica, using measurements and estimates of the components related to the balance for the period of 1996 to 2004. Annual average of downward shortwave radiation at the surface is 81 $Wm^{-2}$ which is 37% of the extraterrestrial value, with the monthly maximum of 188 $Wm^{-2}$ in December and the minimum of 8 $Wm^{-2}$ in June. These values are relatively smaller than those at other stations in Antarctica, which can be attributed to higher cloudy weather conditions in Antarctic front zone. Surface albedo varies between ~0.3 in the austral summer season and ~0.6 in the winter season. As a result, the net shortwave radiation ranges from 117 $Wm^{-2}$ down to 3 $Wm^{-2}$ with annual averages of 43 $Wm^{-2}$. Annual average of the downward longwave radiation shows 278 $Wm^{-2}$, ranging from 263 $Wm^{-2}$ in August to 298 $Wm^{-2}$ in January. The downward longwave radiation is verified to be dependent strongly on the air temperature and specific humidity, accounting for 74% and 79% of the total variance in the longwave radiation, respectively. The net longwave radiation varies between 25 $Wm^{-2}$ and 40 $Wm^{-2}$ with the annual averages of 30 $Wm^{-2}$. Accordingly, the annual average energy balance is dominated by radiative warming of a positive net all-wave radiation from September to next March and radiative cooling of a negative net all-wave radiation from April to August. The net all-wave radiative energy gain and loss at the surface is mostly balanced by turbulent flux of sensible and latent heat. The soil heat flux is of negligible importance in the surface energy balance.