• Ocean and Polar Research
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• v.45 no.2
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• pp.89-102
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• 2023

Climate and environmental changes in the Arctic Ocean due to global warming have been linked to extreme climate change in mid-latitude regions, including the Korean Peninsula, requiring a better understanding of the Arctic climate system based on the paleo-analog. This review introduces three paleoenvironmental research cases using neodymium isotopes (¹⁴³Nd/¹⁴⁴Nd, ε_Nd) measured on two different fractions of marine sediments: silicate-bound 'detrital' and Fe-Mn oxide-dominated 'authigenic' fractions. In the first case, detrital ε_Nd in core HH17-1085-GC on the continental shelf off northern Svalbard was used for tracing changes in sediment provenance and associated glacier behavior over the last 16.3 ka. The second case showed the potential use of authigenic ε_Nd as a quasi-conservative water mass tracer. Three prominent ε_Nd peaks and troughs observed in core PS72/410-1 from the Mendeleev Ridge in the western Arctic Ocean over the past 76 ka suggested episodic meltwater discharge events during 51~46, 39~35 and 21~13 ka BP. The last case proposed the use of the difference between authigenic and detrital ε_Nd as a proxy for reconstructing glacier fluctuation. The idea is based on the assumption that enhanced glacial erosion during glacier advances can supply sufficient freshly-exposed rock substrate for incongruent weathering, potentially leading to greater isotopic decoupling between bedrock and dissolved weathering products as recorded in detrital and authigenic ε_Nd, respectively. Thus, it would be worthwhile to take advantage of sedimentary ε_Nd to improve our understanding of past environmental changes in polar regions.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.63-71
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• 2023

The extreme cold regions, including the South and North Poles, are rich in resources, but there are many constraints on resource development projects due to difficult access and a construction environment that is completely different from that of Korea. In recent years, global warming has increased the demand for the construction of resource exploitation plants. For resource development construction activities, a preliminary site analysis is required to minimize the risk of project implementation. In this study, the factors were analyzed to be considered in construction activities in extreme cold and optimal location selection system based on Geographic information system(GIS) has been developed. As a result of applying the development system to Alberta, Canada, where oil sand development is actively underway, it was confirmed that the results were consistent with the currently operating oil sand mining area.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.257-268
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• 2005

Meiofauna community was surveyed in the Arctic Ocean. Sediment samples were collected from six stations in the east Barents Sea and from five stations in Kongsfjorden, Svalbard during summer 2002. Eight taxa of meiofauna were identified in the Barents Sea. Meiofauna abundance ranged from 245 to 906 indiv.10 $cm^{-2}$ (mean 580 indiv.10 $cm^{-2}$) and total biomass varied from 23 and 404 ${\mu}gC10cm^{-2}$ (mean 184 ${\mug}C10cm^{-2}$) in the Barent Sea. Nematode predominated in meiofauna comprising $95.2\%$ of total abundance and $66.4\%$ of biomass. Copepods, polycheats and sarcomastigophonans were also dominant in the study area. Nine taxa of meiofauna were identified in Kongsfiorden. Meiofauna abundance ranged from 103 to 513 indiv.10 $cm^{-2}$ (mean 292 indiv.10 $cm^{-2}$) and biomass varied from 13 and 196{\mu}gC10\;cm^{-2}$ (mean 94{\mu}gC10\;cm^{-2}$) in the Kongsfiorden. Nematodes predominated in meiofauna, comprising $64.1\%$ of abundance and $64.3\%$ biomass. Copepods, polychaets, and kinorhyncha were also dominant in the study area. The meiofauna abundances from both the study areas well match with the previous reports from the various regions including the temperate areas. However the occurred taxa in the present study are only a half comparing with the reports from temperate zone. Meiofauna abundance, biomass, diversity index and species richness were much higher than in the coastal which were strongly affected by fresh water run off in the Barents Sea. The stations affected by chlorophyll had high abundance and biomass, but low diversity index and spices richness in Kongsfiorden.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.4
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• pp.241-263
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• 2010

KoFlux is a Korean network of micrometeorological tower sites that use eddy covariance methods to monitor the cycles of energy, water, and carbon dioxide between the atmosphere and the key terrestrial ecosystems in Korea. KoFlux embraces the mission of AsiaFlux, i.e. to bring Asia's key ecosystems under observation to ensure quality and sustainability of life on earth. The main purposes of KoFlux are to provide (1) an infrastructure to monitor, compile, archive and distribute data for the science community and (2) a forum and short courses for the application and distribution of knowledge and data between scientists including practitioners. The KoFlux community pursues the vision of AsiaFlux, i.e., "thinking community, learning frontiers" by creating information and knowledge of ecosystem science on carbon, water and energy exchanges in key terrestrial ecosystems in Asia, by promoting multidisciplinary cooperations and integration of scientific researches and practices, and by providing the local communities with sustainable ecosystem services. Currently, KoFlux has seven sites in key terrestrial ecosystems (i.e., five sites in Korea and two sites in the Arctic and Antarctic). KoFlux has systemized a standardized data processing based on scrutiny of the data observed from these ecosystems and synthesized the processed data for constructing database for further uses with open access. Through publications, workshops, and training courses on a regular basis, KoFlux has provided an agora for building networks, exchanging information among flux measurement and modelling experts, and educating scientists in flux measurement and data analysis. Despite such persistent initiatives, the collaborative networking is still limited within the KoFlux community. In order to break the walls between different disciplines and boost up partnership and ownership of the network, KoFlux will be housed in the National Center for Agro-Meteorology (NCAM) at Seoul National University in 2011 and provide several core services of NCAM. Such concerted efforts will facilitate the augmentation of the current monitoring network, the education of the next-generation scientists, and the provision of sustainable ecosystem services to our society.

• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.51-61
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• 2019

Clay minerals, a major component of mud volcano (MV) sediments, are expected to provide important information for characterizing mud volcano formation mechanisms, but clay minerals have rarely been studied. The purpose of this study is to investigate the characteristics of 420 MV and surrounding marine sediments. Clay minerals and grain size were analyzed for 8 box cores from 420 MV and Mackenzie Trough. The relative proportions of the four major clay minerals in the Mackenzie Trough are almost constant in the order of illite, chlorite, kaolinite, and smectite, regardless of the distance from the Mackenzie River. However, the grain size tends to become fining as they move away from the Mackenzie River. Comparing the clay mineral characteristics of river (Colville River, Kuparuk River, Sagavanirktok River, Canning River, Mackenzie River) sediments entering the Beaufort Sea in order to determine the origin of the Mackenzie Trough and 420 MV sediments, the sediments of the Mackenzie Trough are characterized mainly by the Mackenzie River with a low ratio of smectite/illite and a high ratio of kaolinite/chlorite. In 420 MV sediments, the contents of clay minerals decrease in the order of illite, kaolinite, chlorite, and smectite, and the grain size with depth is almost constant. The content of smectite and coarse sediments is about two times higher than the reference core. No river with higher kaolinite content than chlorite exists in the Beaufort Sea, and the ratio of smectite/illite to kaolinite/chlorite is different from the reference core such as the ratio of the Mackenzie River. Compared to the reference core, the high contents of coarse sediments and the constant grain size with depth might be attributed to the ejection by MV. The reference core is interpreted as originating from Mackenzie River, and sediment of 420 MV is interpreted as originating from eruption of MV.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.427-437
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• 2020

Manganese nodules, which are evaluated as potential metal resources, have been found in the Arctic Ocean as well as in the abyssal plains of the Pacific and Indian Oceans. Manganese nodules exhibit strong variations in the morphology, internal texture, chemical composition and mineralogy as they grow. The relationship between the texture and chemical elemental composition during the growth process is well documented, but the mineral composition variation during the growth process is not. Because the manganese oxide minerals in nodules are fine-grained and poorly crystalline, quantitative analysis for the mineral composition is challenging for the bulk nodule sample. This study investigated the internal texture and Mn-oxide mineral composition of manganese nodules obtained from the East Siberian Sea. Semi-quantitative analysis was attempted for three main Mn-oxide minerals constituting the manganese nodules (i.e., todorokite, buserite and birnessite) using the peak area ratio of X-ray diffraction analysis graphs. In the East Siberian Sea manganese nodules, birnessite is more abundant than buserite or todorokite, and no correlation is found between the mineral composition and the internal texture. Instead a correlation is found between the relative content of todorokite and the lamellae depth. The todorokite content tends to increase from the surface to the core of the nodules, which can be attributed to a recrystallization process or difference in the growth rate within the nodule. This study shows that semi-quantitative analysis of manganese oxide minerals using the peak area ratio is useful in the mineralogical study of manganese nodules.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.275-291
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• 2023

Global warming has made the polar regions more accessible, leading to increased demand for the construction of new resource-development plants in oil-rich permafrost regions. The selection of locations of resource-development plants in permafrost regions should consider the surface displacement resulting from thawing and freezing of the active layer of permafrost. However, few studies have considered surface displacement in the selection of optimal locations of resource-development plants in permafrost region. In this study, Analytic Hierarchy Process (AHP) analysis using a range of geospatial information variables was performed to select optimal locations for the construction of oil-sands development plants in the permafrost region of southern Athabasca, Alberta, Canada, including consideration of surface displacement. The surface displacement velocity was estimated by applying the Small BAseline Subset Interferometric Synthetic Aperture Radar technique to time-series Advanced Land Observing Satellite Phased Array L-band Synthetic Aperture Radar images acquired from February 2007 to March 2011. ERA5 reanalysis data were used to generate geospatial data for air temperature, surface temperature, and soil temperature averaged for the period 2000~2010. Geospatial data for roads and railways provided by Statistics Canada and land cover maps distributed by the North American Commission for Environmental Cooperation were also used in the AHP analysis. The suitability of sites analyzed using land cover, surface displacement, and road accessibility as the three most important geospatial factors was validated using the locations of oil-sand plants built since 2010. The sensitivity of surface displacement to the determination of location suitability was found to be very high. We confirm that surface displacement should be considered in the selection of optimal locations for the construction of new resource-development plants in permafrost regions.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1166-1176
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• 2011

The prospect in opening the arctic trade transportation route on a year-round basis offers vast opportunity of exploring untapped resources and shortened navigational routes. In addition, the environment's remoteness and lack of technical experiences remains a big challenge for the maritime industry. With this, engine designers and makers are continually investigating, specifically optimizing propulsion shafting system design, to meet the environmental and technical challenges of the region. The International Association of Classification Society, specifically machinery requirements for polar class ships(IACS UR13), embodies the propulsion shafting design requirements for ice class vessels. However, the necessity to upgrade the various features of the unified rules in meeting current polar requirements is acknowledged by IACS and other classification societies. For the polar class propulsion shafting system, it is perceived that the main source of excitation will be the propeller - ice load interaction. The milling - and the impact load, in addition to the load cases interpreted by IACS, contribute greatly to the overall characteristic of the system and due considerations are given during the propulsion design stage. This paper will expound on the excitation load estimation factors affecting the dynamic response of the different propulsion shafting system design. It is anticipated that detailed understanding of these factors will have a significant role during propulsion shafting design in the future.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.171-179
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• 2011

The legally protected trees distributed in Gwangju City is 68 individuals belong to 9 taxa. Among the legally protected trees recorded in environment white paper, Quercus dentata located in Gwangsan-gu Eunnam-dong Shinga village must come to correct Quercus liena, Populus nigra var. italica of Byeokjin village of Seo-gu Byeokjin-dong change to Salix glandulosa and Pinus densiflora of Sukjung-dong, Nam-gu should be alter into Pinus densiflora for. multicaulis. IPCC make an estimate the mean temperature multiplies best $6.4^{\circ}C$ and sea level of 59 cm rises and is warning that the North-Pole glacier may have melted mostly and 95% of bio-species on earth may falls at extinction crisis on the late 21th century. If apply IPCC estimate result to evaluate climate change vulnerability through the legally protected trees of Gwangju City, it should be estimated that mean minimum temperature of the coldest month of Gwangju City in the late 21th century result in higher than $3^{\circ}C$ as mean minimum temperature, January in Cheju Island at present. Therefore, it is estimate that the legally protected trees of Cheju Island such as Pinus thunbergii, Celtis sinensis, Aphananthe aspera and a evergreen broadleaf trees will grow up well in Gwangju City area in the late 21th century. The other hand, P. densiflora for. multicaulis and zelkova serrata as the legally protected trees that appear together in Seoul and Gwangju will be estimate by something to expose show vulnerability in region of Gwangju City.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.83-83
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• 2015

현재 인류가 직면한 에너지 부문의 큰 난제는 화석연료의 한정된 매장이기도 하지만 그 사용에 따른 환경오염으로 인한 피해들이 더 큰 문제로 대두되고 있다. 그중 지구 온난화의 영향으로 최근 세계에 국지적인 홍수, 가뭄, 태풍등의 기후 불안정으로 피해보는 상황이 가속화 되고 있다. 또한, 북극지방의 해빙으로 해수면 상승이 예상되며 머지않은 시간에 해수면 상승의 직접적인 피해가 인류에게 오리라는 보고가 많이 발표되고 있다. 그런데 우리가 더욱 중요한 것은 지구촌83의 관성이 크기 때문에 지구 온난화 와 해수면 상승이 인류에 큰 피해를 미치기 시작할 때는 이미 돌이킬 수 없는 상황에 진입해버린다는 사실을 간과하고 있는다는 것이다. 그러므로 과학적 분석에 근거하여 피해를 축소하기위한 활동을 실천해야할 시기이다. 특히, 우리나라의 경우 에너지의 97% 이상을 해외에서 수입하고 있으며, 세계에너지 소비 10위, 석유 소비 7위의 열악한 에너지 자원 빈국인 만큼, 중장기적인 관점에서 석유의존도를 개선하고 신재생에너지원을 확보하는 등 대책마련이 시급한 실정이다. 신재생에너지원으로 현재까지 가장 큰 역할을 해왔던 것 중의 하나가 풍력발전기인데, 오늘날 세계 풍력에 의한 발전량은 세계 총 발전량의 2% 미만에 불과하이다. 이러한 풍력 시장에 발맞춰 국내에서도 풍력발전기 개발에 많은 힘을 쏟고 있는데, 2002년부터 750 kW급 풍력발전기가 처음 개발되기 시작하였고, 이후 2 MW급 풍력발전기와 3 MW급 풍력발전기가 개발되었으며, 최근에는 5 MW와 7.5 MW급등 초대형 풍력발전기가 대기업 중심으로 개발 진행되고 있었으나, 2008년 세계 금융위기 이후 세계 경기침체의 영향으로 국내 풍력산업도 적지않은 영향으로 구조조정되어 기존 7~8개 풍력발전기 제조사들이 3개사 이하로 축소되고 있다. 이에 정부 및 전라남도는 해상풍력산업을 침체기를 겪는 조선산업의 대체산업으로 육성하기위해, 정부 주도로 부안 앞바다에 2.5 GW 해상풍력발전단지개발을 준비 중에 있으며, 전라남도는 전남 서해안에 4 GW 해상풍력발전단지 개발을 서두드고 있다. 특히, 전라남도는 국내에서 가장 많은 풍력에너지 포텐셜을 가지고 있으며, 바람의 질 또한 우수하여 이를 지역산업 활성화의 모멘텀으로 가져가기위해 많은 노력을 기울이고 있다. 그 일례로 영광군 백수읍 하사리 바닷가 $4,342m^2$ 부지에 "풍력테스트베드"를 개발하여 국내 풍력발전기 제조사들이 활용하도록 도움을 주고 있다. 종래의 테스트베드는 해외지역을 이용하였는데, 이는 국내에서 개발된 풍력발전기들이 국제인증을 받기위해 바람의 질이 좋은 해외 테스트베드에 설치되어 평가받았으며 고가의 비용이 소모되었다. 제주도에 테스트베드 장소가 있긴 하지만 수용 규모가 작아 풍력발전기 제조사들이 대기할 수 없어 해외로 나가는 실정에 전라남도의 내륙 테스트베드를 개발함으로서 풍력발전기 제조사들에게 큰 도움을 주고 있다. 본 보고에서는 국가 해상풍력 산업발전의 단계별 전략과 전라남도의 해상풍력산업의 방향 그리고 풍력테스트베드의 현황을 소개하고자 한다.