https://repository.kopri.re.kr/handle/201206/5287 2026-04-19T16:17:54Z https://repository.kopri.re.kr/handle/201206/6640 Title: High-resolution diatom analysis of a core sediment in the Bransfield strait, Antarctica Authors: Lee, Jong-Deock; Yoon, Ho Il; Yoo, Kyu-Cheul; Bak, Young-Suk Abstract: A box core BC02-EB03 obtained in the eastern basin of the Bransfield Strait (West Antarctica) shows high-resolution laminated layers of diatom ooze sediments. The basin is influenced by the warm and less saline Bellingshausen Sea water and the cold and saline Weddell Sea water. The range of diatom valves per gram of dry sediment was from 8.6 to 22.0×107 in quantitative diatom assemblage analysis. Two facies (upper and lower units) are divided upon the basis of frequency of the diatom taxa and magnetic susceptibility values. The lower unit (22~60 cm) is characterized by the lower magnetic susceptibility and higher number of diatom valves per gram sediment. It contains diatom mass influx of Chaetoceros resting spores, Corethron criophilum, and Rhizosolenia styliformis which are associated with the stratification of surface water of ice-shelf's edge by the increased meltwater between austral summer and fall. Meanwhile, the upper unit (0~22 cm) displays relative decrease of critical species and lower diatom abundances according to the relative increase of terrigenous supply during modern warming which reflects the rapid regional warming of the Antarctic Peninsula. 2009-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6648 Title: Glaciomarine sedimentation on the continental rise from the Bellingshausen Sea, West Antarctica Authors: Yoo, Kyu-Cheul; Yoon, Ho Il; Lim, Hyoun Soo; Lee, Jae Il Abstract: The effects of glaciomarine sedimentary processes are recognised from variation of sedimentary facies in two deep sea cores taken from the continental rise of the western Antarctic Peninsula. Two sediment cores (one gravity core and one piston core) were visually described, logged for magnetic susceptibility, and X-radiographed. Their analyses were performed for grain size, geochemistry, and clay minerals. Three sediment types associated with distinct sedimentary processes of last glacial, deglaciation and Holocene are recognized: (1) Terrigenous mud of glacial sediment accumulated from a combination of sedimentary processes including contour/turbidity currents and turbid plumes, (2) slightly bioturbated silt mud derived from meltwater discharges, and (3) hemipelagic mud of interglacial sediment accumulated from the pelagic settling of bioclasts and ice-rafted/wind-transported detritus. Two depositional settings are interpreted within sediment drift 1 (side of the drift) and sediment drift 3 (top of the upper rise), each characterized by the dominance/interaction of one or several depositional processes. 2008-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6656 Title: Optical Dating of Sorted Circles in King George Island, Shetland Islands, West Antarctica as a Potential Time Marker for Local Glacier Retreat Authors: 김종욱; Yoon, Ho Il; 장호완; 임창복; Chung, Changsic; Lim, Hyoun Soo; Choi, Jeong Heon Abstract: During the deglaciation period, the glaciers dump till sediments as they melt away, thus the depositional ages of these sediments provide important information on the timing of glacial retreat(the initiation and the duration of the local deglaciation). However, in many cases, direct dating of till sediments is not readily possible because of a lack of suitable material for conventional dating methods, except where 14C dating is applicable. In addition, optical dating on these sediments has not been always successful because most glacigenic deposits usually have little chances of being exposed to sufficient sunlight, which results in significant overestimation in optical ages. The till sediments, however, sometimes form a diagnostic geomorphic structure, referred to as sorted circle, hrough repeated freeze-thaw cycles on flat areas in polar regions. In the course of its formation, the soil particles in the active layer may move up and down actively, and therefore some of these particles are presumed to have chances to be exposed to sufficient sunlight for the latent OSL signals to be completely bleached, which is one of the most important prerequisite process for reliable optical dating. To test this hypothesis, we collected sediment samples from two sorted circles at the elevation of 41 m and 66 m in King George Island, South Shetland Islands, West Antarctica. Quartz grains extracted from these sediments have various undesirable OSL properties for routine SAR-based optical dating. For instance, the OSL signals of those quartz grains do not have fast OSL component that is the usual signal for optical dating. In dose recovery test using both LM-OSL SAR and conventional SAR procedure, the recovered doses were lower than the given dose by about 10 % or less. The OSL age obtained on the basis of weighted mean De value of 18±1 Gy was 11±1 ka, which implies that the deglaciation near King Sejong station may have occurred before 11±1 ka. 2008-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/7829 Title: Heavy Metal Concentrations In Fruticose Lichen, Usnea Aurantiacoatra of King George Island, South Shetland Islands, West Antarctica Authors: Lim, Hyounsoo; Seo, Dong Cheol; 허재선; Cho, Ju-Sik; Heo, Jong Soo; 박양주; Kim, Ji Hee; Lee, Jae Il Abstract: The accumulation of various heavy metals in the fruticose lichen, Usnea aurantiacoatra is reported in the vicinity of the Korean research station located in the Barton Peninsula, King George Island. During the 2006/2007 Korea Antarctic Research Program (KARP) expedition, lichen samples were collected from 25 sites. At each site, collected samples were classified into three groups according to their size and weight: young (ca. 0.1 g), middle (ca. 0.7 g) and old (ca. 5 g) groups. Heavy metal concentrations (Cr, Cu, Zn, As, Cd, Pb, Hg, Co, Ni, Ag, V, Se, Rb, Sr, Ba, U) in lichen thalli were analyzed by induced coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrophotometry (AAS). As expected, lead concentrations showed a dramatic decrease with distance from the research station, suggesting that the bioaccumulation of Pb in lichen has been influenced by the anthropogenic sources. Similar but weak patterns are also found in distribution patterns of Cr and V. However, no geographical patterns were observed in most of the heavy metals analyzed. Our analytical data for the age groups show that mean values of Cr, Al, V and Rb were statistically higher in old group, while those of Cu, Zn, Se and Pb were higher in young group. This result indicates that lichen samples of similar size should be collected for the comparison of heavy metal concentrations. 2008-01-01T00:00:00Z