• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.49-52
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• 2001

The more the population grow, the severer the shortage of a basic human needs such as food, clean water, energy resources and so on. We had proved the possibility of utilizing deep ocean water as a environmental friendly resource to solve comprehensively above-mentioned problems for mankind based on observation and analysis of water quality. This study aims to evaluate feasibility of deep ocean water application, and establish multipurpose development and cascade utilization system of deep ocean water in the coastal zone of East sea to promote ocean development and fisheries industries.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.168-177
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• 2008

Trafficablility of a miner and potential environmental impacts due to mining activities should be considered in the selection of a commercial manganese nodule mining site. These two factors can be evaluated comparatively with physical properties and shear strength of sea-bed sediments. For the qualitative comparison of potential minig sites in terms of these two factors, physical properties such as water contents, void ratios, porosities, and grain densities, and shear strengths of surface sediments were determined for the three potential manganese nodule mining sites(KR1, KR2, and KR5) in the Korean manganese nodule contract area, northeast Pacific. For the study, sediment samples were collected from 107 stations from 2004 to 2006. The physical properties of surface sediments showed more significant differences between northern(KR1, KR2) and southern(KR5) blocks than between northern blocks(KR1 vs. KR2). Water content, void ratio, and porosity of sediments from KR5 were relatively higher than those from KR1 and KR2. Grain density of sediments from KR5 was relatively lower than those from KR1 and KR2. Shear strengths of the top 10cm sediments were higher in KR1 and KR2, whereas those of the deeper part were highest in KR5 block. Generally, sediments of high water contents are less suspendible than those of the low water contents by benthic disturbances, thus less disturbance is expected in the sediments of high water content by mining activities. In terms of trafficability, the shear strength of sediment below 10 cm deep is more important than shallower part because miner will disturb at least top 10 cm interval of the surface sediments. Base on these results, we conclude that KR5 area will be the best site for commercial mining among three investigated sites in this study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.35-40
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• 2004

Ship can not sail without water. Ships sail along different routes with different natural conditions. Thus ships sailing at different sea areas have their respective characteristics. The northern sea area and the southern one of China have different characteristics, that is to song, the sea in the northern area is shallow and that in the southern area is deep, Chinese ships developed into different types in order to adapt to this.

• Journal of the Korean earth science society
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• v.44 no.4
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• pp.264-274
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• 2023

The Korea Strait comprises a continental shelf in a shallow sea that experienced glacio-eustastic sea-level changes during the Quaternary period. A long core of 76.6 m in length was acquired at the South Sea Drilling Project site (SSDP-101; 34°19.666'E and 128°16.335'N) with a 60 m water deep. The uppermost massive sand beds were interpreted as sandy sediments of the nearshore marine sand ridge in the shallow sea during the transgression of sea level, whereas the lower parts of alternating sandy and muddy beds were interpreted as deposits in marsh, estuary, and tidal flat environments. A three-layered geoacoustic model was reconstructed for the sedimentary succession in the high-resolution seismic profile based on a 140-grain size and sediment type of core SSDP-101. For the actual underwater simulation and experiments, the in-situ P-wave speeds were calculated using the sound speed ratio of the Hamilton method.

• Journal of Ocean Engineering and Technology
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• v.31 no.5
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• pp.364-370
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• 2017

A numerical model based on the mode superposition method is used to study the vortex-induced vibration response characteristics of a deep-sea riser such as steel catenary riser (SCR). A steel catenary riser can be modeled using a flexible cable with simple supports at both ends. The natural frequency, mode shape and mode curvature of the riser are calculated and the vortex-induced vibration response of the riser is obtained using the equilibrium of the input and output power. The mode superposition method is applied to the vibrational stresses for each mode to calculate the overall riser fatigue life.

• Geotechnical Engineering
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• v.6 no.4
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• pp.65-74
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• 1990

This paper presents triaxial test (CIVC and CKOUC) results on normally consolidated deep sea clay samples. Based on the test results the pore pressure-strain relations for both isotropicaly and anisotropicaly consgidated samples are expressed with hyperbolic functions of the major princpal strain. The analysis of the difference in pore pressure behavior due to the anisotropy in consolidation stress is carried out with the effective stress pathos of CIVC and CKOUC and finds a factor which correlates the pore pressure of two types of test.

• Animal Systematics, Evolution and Diversity
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• v.32 no.3
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• pp.197-206
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• 2016

Two cold-water coral taxa, Octocorallia in the class Anthozoa and Stylasteridae in the class Hydrozoa, were identified. Deep-water samples were collected in fishing nets at depths ranging between 20 and 200 m along the coasts of the East Sea in Korea from 1976 to 1993. The two species found in this study represent new records for Korea: Paragorgia arborea (Linnaeus, 1758) in the class Anthozoa, and Stylaster profundiporus Broch, 1936 in the class Hydrozoa. Two families, Paragorgiidae and Stylasteridae, are also newly recorded in Korea. Furthermore, the species name of another cold-water gorgonian species, Primnoa pacifica (Kinoshita, 1907) in the family Primnoidae, is amended in this report. The two newly recorded cold-water coral species from Korea are described in detail based on their morphological characteristics. Paragorgia arborea is characterized by its growth form, medulla and cortex, zooid dimorphism, canal system, and spicule composition. Stylaster profundiporus is distinguished by its external skeletal characteristics, such as the coordination of dactylopores and gastropores, presence or absence of gastrostyles and dactylostyles, cyclosystem orientation, ampullar position, gastropore tube shape, and coenosteal texture.

• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.13-15
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• 2003

Studies on marine microbial diversity using direct analysis of rRNA sequences have revealed previously unrecognized microbes and novel phylogenetic lineages that represent major components of global microbial assemblages. This diversity in the marine biosphere offers opportunities for research and application in the field of biotechnology; global gas exchange, nutrient and element cycling, biomass md food production, marine bioproducts, and bioprocesses. Especially, deep-sea encompasses the extremes of virtually at] environmental parameters found on Earth and provides extreme microorganisms. In this study several extreme microorganisms were successfully isolated from the deep-sea sediment samples obtained by joining ocean cruises for last 2 years and some of them will be introduced.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.139-143
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• 2009

• Ocean and Polar Research
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• v.24 no.3
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• pp.215-223
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• 2002

Symbiosis of chemoautrophic bacteria with the members of hydrothermal vent and cold seep communities in the deep-sea were examined by histology using transmission electron microscopy; Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin; and Ifremeria nautilei from the North Fiji Basin. Two species of Bathymodiolus, each from Sagami Bay and the Iheya Ridge harbored methane-oxidizing symbionts within their gill tissues. Vent gastropod Ifremeria nautilei from the hydrothermal vents of the North Fiji Basin housed two types of symbionts; one sulfur-oxidizing type and the other methane-oxidizing type. The occurrence of chemosynthetic symbionts in these organisms were expected before-hand based on the ecological observations of their habit. The other members of these groups from world oceans and the recent advances in the symbiosis of the vent and seep communities were reviewed.