• Journal of Environmental Science International
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• v.21 no.2
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• pp.125-133
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• 2012

Climatological trend for the period of 1970 to 2009 in sea water temperature around the Antarctic Peninsular waters in the Southern Ocean was investigated. During the period from 1970 to 2009, sea water temperature in the top 500 m water column except 100 m increased at a rate of $0.003-0.011^{\circ}C{\cdot}yr^{-1}$, but at 100 m it decreased at a rate of $-0.003^{\circ}C{\cdot}yr^{-1}$. Although long-term trend is generally warming, there were several periods of sharp changes between 1970 and 2009. Annual mean sea water temperature between surface and 500 m except 100 m decreased from the early of 1970s to the end of 1980s, and then it increased to the end of 2000s. In the entire water column between the surface and 500 m, sea water temperature closely correlated with the El Nino events expressed as the Southern Oscillation Index(SOI), and SOI and sea water temperature have a dominant period of about 3-5 years and decade.

• Journal of the Korean Geophysical Society
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• v.8 no.4
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• pp.215-219
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• 2005

Multichannel seismic survey has conducted along the South Scotia Ridge which is located in the northern part of Weddell sea, Antarctic sea. The South Scotia Ridge is part of continental crust extended from Antarctic Peninsula. It borders on Oceanic plates, the Scotia sea plate and Powell basin. Transtensional tectonics along the sinistral transform fault plate boundary led to the creation of the present tectonic geomorphology of the South Scotia Ridge. The fan-shaped deposits with angular unconformities in the central depression is interpreted as a divergent tectonic movement along the ridge.

• The Korean Journal of Quaternary Research
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• v.5 no.1
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• pp.47-61
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• 1991

Textural analysis of gravels of raised beach (old beach) in the Weaver Peninsula, King George Island, Antarctica has been carried out as a first part study among 20 other sites surveyed in the Weaver Peninsula and Barton Peninsula, King George Island. The raised beach described as WP-5 in this paper is 3.95 m higher than the present beach in elevation. And it is described as old beach. The beach shows typical subenvironment, that is, beach berm and beach face. Mean size, mean roundness and mean sphericity of gravels from beach berm are -4.10ø, 0.44 and 0.66 respectively. However, mean size, mean roundness and mean sphericity from beach face are -4.23ø, 0.41 and 0.67 respectively. In particular, it seems to be worthy to note the differences of textural parameters between Antarctic glacio-marine beach gravels and temperate and normal marine beach gravels. Under such conception the present study wishes to show only textural parameters, i.e., size, roundness, sphericity and shape obtained from the analysis of Antarctic glacio-marine beach gravels.

• Ocean and Polar Research
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• v.26 no.1
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• pp.87-101
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• 2004

This paper delineated the ecology including movement (departure from the rookery and returning to the rookery), egg-laying, and hatch of the penguins occurred in the cold years and a less cold year in the vicinity of King Sejong Station, King George Island off the Antarctic Peninsula. The years of 1988, 1991, 1992, and 1995 were selected as cold years and the year of 2001 was selected as a less cold year based on the mean annual temperature of the years. Gentoo Penguin (Pygoscelis papua) left their rookery in May, meanwhile some remained around the station. They returned in middle-September in the less cold .year, and returned in late-September to early-October in the cold years. Chinstrap Penguin (Pygoscelis antarctica) left their rookery in early-April in the cold years as well as in the less cold year without exception. They returned to the rookery in late-October to early-November in cold years, meanwhile in early-October in the less cold year. This difference in the returning of this bird seems to be related with the exposed sea water, i.e., sea ice condition to feed in the sea. The global warming will lead to the appearance of birds which breed in the Sub-Antarctic. For example, one pair of King Penguin (Aptenodytes patagonicus) was observed in the Maxwell Bay in austral summer. And a pair of snide-like bird was recently observed for the first time in November 2001 at the penguin rookery located in the Barton Peninsula, King George Island. And it will also lead to the disappearance of an Emperor Penguin (Aptenodytes forsteri) which appeared in the full winter when Maxwell Bay and Marian Cove were frozen. It seems that the behaviour of the penguins observed around the station shows the complex effects of the ecology of the birds in combination with the natural environments, which include feeding strategy and areas, animal Instincts, exposed terrain related to weather conditions, and globa1 warming. It is necessary to take further observation and carry out systematic researches on the birds including penguins around the station which show the ecology of the birds as well as the environmental changes.

• Ocean and Polar Research
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• v.25 no.2
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• pp.201-211
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• 2003

Bottom simulating reflectors (BSR), representing the base of the gas hydrate stability field, are widespread on the South Shetland continental margin (SSM), Antarctic Peninsula. With the phase diagram fur the gas hydrate stability field, heat flow can be derived from the BSR depth beneath the seafloor determined on multichannel seismic profiles. The heat flow values in the study area range from $50mW/m^2$ to $85mW/m^2$, averaging to $65mW/m^2$. Small deviation from the average heat flow values suggests that heat flow regime of the study area is relatively stable. The landward decrease of heat flow from the South Shetland Trench to the continental shelf would be attributed to the landward thickening of the accretionary prism and the upward advection of heat associated with fluid expulsion. The continental slope 1500m to 3000m deep, where BSRs are most distinguished in the SSM, shows relatively large variation of heat flow possibly due to complex tectonic activities in the study area. The local high heat flow anomalies observed along the slope may be caused by heat transport mechanisms along a NW-SE trending large-scale fault.

• Journal of the Korean Geophysical Society
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• v.2 no.4
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• pp.241-250
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• 1999

Reflection coefficients of the seafloor have been calculated from the amplitude ratio of secondary to primary water bottom reflection in seismic data obtained from Bransfield Strait, Antarctic Peninsula. Test processing for the coefficients shows that moving average is effective to reduce severe fluctuation of the coefficient measured at each point. Relationship between the coefficients and the properties of water bottom is analyzed to illuminate geological environment. In the central Bransfield Basin, the magnitude of reflection coefficients decreases as it is distant from the sedimentary sources. Reflection coefficients range from 0.12 to 0.2 near the continental slope of the basin, and from 0.1 to 0.12 in the basin floor. In the western Bransfield basin, reflection coefficients between 0.2 to 0.3 are obtained from the area eroded by glacial movement. On the volcanic structures near Deception Island, the coefficients show relatively high values more than 0.2. Paleo-geological structures uplifted by tectonic movement and outcropped by glacial erosion have relatively high coefficients.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.152-163
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• 2001

Based upon the sedimentological, geochemical and micropaleontological analyses of two sediment cores from the Antarctic Peninsula (AP), three distinct lithological units can be recognized: (1) ice-proximal an/or ice-distal diamictons in the lower part of the cores, accumulated just seaward of the grounding line of the ice shlef until 11,000 yrs BP; (2) diatomaceous mud between 6,000 and 2,500 yrs BP in the middle part, resulted from a large influx of organic materials by enhanced production of open marine condition; (3) diatomaceous sandy mud since 2,500 yrs BP, characterized by an increase in sand content and decrease in TOC and diatom abundance in the lower layers, which reflects the formation of more extensive and seasonally persistent sea ice. Based on the C-14 radiocarbon dating, the sub-ice shlef deposition of the diamicton on the AP western shelf completed around 11,000 yrs BP. Colder condition was reinstated between 12,800 and 11,600 BP with a dropin TOC content and diatom abundance, which is coincident with the Younger Dryas event in the North Atlanticregion. At this time, the ice shelf, that is now absent in the study area, appears to advance as evidenced by an abrupt increase in sea-ice taxa. A climatic optimum is recognized between 9,000 and 2,500 BP, coincide witha mid-Holocene climatic optimum 'Hypsithermal Warm Period' from the other Antarctic sites. During this time, diatomaceous mud accumulated by a large influx of organic materials by enhanced production occurred in openmarine condition. Around 2,500 BP, diatomaceous sandy mud reflects the formation of more extensive and seasonally persistent sea ice, coincident with the onset of the Neoglacial in the Antarctic. Our results provide evidence of climatic change from the Antarctic Peninsula`s western shelf that helps in determining the existence and timing of Holocene milennial-scale climatic events in the Southern Hemisphere.

• Journal of the Korean earth science society
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• v.39 no.5
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• pp.473-482
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• 2018

During the period of 2002 to 2017, the Gravity Recovery And Climate Experiment (GRACE) had observed time-varying gravity changes with unprecedented accuracy. The GRACE science data centers provide the monthly gravity solutions after removing the sub-monthly mass fluctuation using geophysical models. However, model misfit makes the solutions to be contaminated by aliasing errors, which exhibits peculiar north-south stripes. Two conventional filters are used to reduce the errors, but signals with similar spatial patterns to the errors are also removed during the filtering procedure. This would be particularly problematic for estimating the ice mass changes in Western Antarctic Ice Sheet (WAIS) and Antarctic Peninsula (AP) due to their similar spatial pattern to the elongated north-south direction. In this study, we introduce an alternative filter to remove aliasing errors using the Empirical Orthogonal Functions (EOF) analysis. EOF can decompose data into different modes, and thus is useful to separate signals from noise. Therefore, the aliasing errors are effectively suppressed through EOF method. In particular, the month-to-month mass changes in WAIS and AP, which have been significantly contaminated by aliasing errors, can be recovered using EOF method.

• 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.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.289-296
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• 2019

We investigated the mortality and the oxidative damages of Deschampsia antarctica in response to waterlogging stress. In field, we compared the changes in the density of D. antarctica tuft at the two different sites over 3 years. The soil water content at site 2 was 6-fold higher than that of site 1, and the density of D. antarctica tuft decreased significantly by 55.4% at site 2 for 3 years, but there was no significant change at site 1. Experimental results in growth chamber showed that the $H_2O_2$ and malondialdehyde content increased under root-flooding treatment (hypoxic conditions-deficiency of $O_2$), but any significant change was not perceptible under the shoot-flooding treatment (anoxic condition-absence of $O_2$). However, total chlorophyll, soluble sugar, protein content, and phenolic compound decreased under the shoot-flooding treatment. In addition, the catalase activity increased significantly on the 1st day of flooding. These results indicate that hypoxic conditions may lead to the overproduction of reactive oxygen species, and anoxic conditions can deplete primary metabolites such as sugars and protein in the leaf tissues of D. antarctica. Under present warming trend in Antarctic Peninsula, D. antarctica tuft growing near the shoreline might more frequently experience flooding due to glacier melting and inundation of seawater, which can enhance the risk of this plant mortality.