• Title/Summary/Keyword: East Sea current

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A Study on the South Korean Coastal Front (한국 남해연안 전선에 관한 연구)

  • Gong, Yeoung
    • 한국해양학회지
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    • v.1
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    • pp.25-36
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    • 1971
  • The structure of the south Korean coastal front, their fluctuation, the properties and the probable effects of the front on the mackerel fishery are discussed based on the data of 26 cruises in 1967-1969 in the southern waters of Korea. In the south Korean coastal water the annual variations of the properties shows the greatest magnitude among the other water masses in the north of East China Sea. The salinity profile provides a fairly accurate description of the interface between the two kinds of water and agree with the temperature structure in winter. The temperature front does not always coincide with the salinity front in summer, while the former corresponds to the later in winter. The sharpest and most stable front between the Tsushima Warm Current and the south Koren coastal water was found in autumn and winter. In autumn 1969, the most successful catches of mackerel was recorded in the south Korean front of great borizontal gradients of properties(temperature 5.0$^{\circ}C$/10miles, salinity 1.2 /10miles) in the east of Cheju Is. If future investigation finds the peculiar oceanographical conditions like that shown in summer, 1969, the conditions of frontal layer in coming autumn will be estimated and finally the success of the mackerel fishery will be predictable from preseason information on temperature and salinity structure in the southern waters of Korea.

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ROKN's Response Strategy to North Korea's SLBM Threat (북한 SLBM 위협과 대응방향)

  • Moon, Chang-Hwan
    • Strategy21
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    • s.40
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    • pp.82-114
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    • 2016
  • The purpose of this article is to analyze the progress of North Korea's SLBM threat, and to assess the technological capacity and threat level of its SLBMs. Currently, North Korea has approximately 1000 ballistic missiles, such as the SCUD, Musudan, and Nodong, in stock. This article pays close attention to the background and strategical implication behind North Korea's obsession with developing SLBMs despite possessing sufficient means to launch provocations with its current arsenal of ground based ballistic missiles and conventional weapons. Based on the abovementioned analysis, this article will recommend possible response directions for the ROK Armed Forces to North Korea's SLBM threat. It is highly difficult to detect SLBMs due to its stealthy nature, as it is launched underwater after covert infiltration. North Korea's SLBM is considered a game changer in that even one SLBM can significantly change the strategic balance of North East Asia. North Korea's SLBM test launch in August has made a 500km flight, landing 80km inside the JADIZ (Japan Air Defense Identification Zone), and as such, it is assessed that North Korea already possesses underwater ejection and cold launch capabilities. The most realistic response to North Korea's imminent SLBM threat is bolstering anti-submarine capabilities. ROK Armed Forces need to upgrade its underwater kill-chain by modernizing and introducing new airborne anti-submarine assets and nuclear-powered submarines, among many options. Moreover, we should integrate SM-3 missiles with the Aegis Combat system that possess strong detection capabilities and flexibility, thereby establishing a sea-based Ballistic Missle Defense (BMD) system centered around the Aegis Combat System, as sea-based ballistic missile threats are best countered out in the seas. Finally, the capabilities gap that could arise as a result of budgetary concerns and timing of fielding new assets should be filled by establishing firm ROK-US-Japan combined defense posture.

Investigation of interference current distribution in a long line scallop cage aquaculture (수하식 큰가리비 양식의 채롱간 조류의 흐름 간섭현상 규명)

  • Kim, Hyun-Young;OH, Bong-Se;Cha, Bong-Jin;Park, Mi-Seon
    • The Korean Journal of Malacology
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    • v.30 no.3
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    • pp.273-279
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    • 2014
  • The mass mortalities have been occurring of Korean scallop Patinopecten yessoensis from 1997's to now in Korea east sea. Cages behavior and interference effect (common name; curtain effect) between scallop cages were investigated in culture grounds on the eastern coastal waters of Korea for understand to mechanism of rising about mass mortalities of Korean scallop quickly. The first experiment was carried out in circulating water channel to assess inclination angel from relationship between velocity and cages interval, velocity with culture cages position. An angle of inclination of scallop culture cages were 94.6 to 92.3 degree under a several velocity which were from 0.1 m/s and 131.9 to 118.1 degree under 0.5 m/s with cages interval were 1 m, 94.3 to 91.0 degree under velocity is 0.1 m/s and 133.2 to 122.4 degree under 0.5 m/s with cages interval were 1.5 m and 94.6 to 96.4 degree under velocity is 0.1 m/s and 131.7 to 131.8 under 0.5 m/s with cages interval were 2 m. The second experiment was designed to prove the tank test. Velocities were measured inside and outside of the scallop culture ground at eastern sea of Korea. The velocity of inside of the culture was the slowest as 0.1m/s. In this result, interference between former cage and after cage was occurred.

The Effect of Wind Stress in the Southwestern Coastal Waters of the Japan Sea (동해 연안역 해수순환에 대한 바람응력 효과)

  • CHANG Sun-Duck;KIM Jong-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.6
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    • pp.538-548
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    • 1993
  • In order to estimate the influence of wind stress in the southwestern coastal waters of the Japan Sea, the wind stress was estimated from the shipboard wind data of the Fisheries Research and Development Agency along the serial observation lines and Buoy No. 6 of the Japan Meteorological Agency. 5,100 wind data are used to construct a data set of monthly mean wind stress during 10 years from 1978 to 1987. The negative values of the mean zonal wind stress curl at Ulleung Basin in the study area seem to be responsible for the formation of the warm core. The volume transport of the East Korea Warm Current are estimated quantitatively by the variations of the Ekman transport associated with the reversing direction of the monsoon. And the distribution of the warm core is explained by the simple three layer model.

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Approach Characteristics and Status of Exhibition-culture Facilities in Gangneung (강릉지역 전시문화시설의 현황 및 진입특징)

  • Byun, Kyeonghwa;Cho, Won-Seok;Kwon, Young-Gyu
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.1
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    • pp.73-81
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    • 2015
  • The purpose of this study is to analyze the approach characteristics, relation to other facilities, and current status focusing on 28 total of exhibition-culture facilities in Gangneung. The results are following as. First, 19 facilities are located in urban area and nine are located in country side. With locational characteristics of Gangneung which is mountains in west and sea to east, three are located in high hill side and four are in sea shore among nine facilities. Facilities in urban area converge to Gungpodae and Ojukhuk which are symbol space in Gangneung. Those facilities started to have been increased from 1990s and rapidly increased from 2000s. The reason is that people have been interested in culture and art in society in general. In building structure, buildings related with traditional contents were constructed with wooden structure while buildings have been mainly constructed with modern ways such as steel and reinforced concrete structure. Second, the 28 facilities are classified into three types by function of other space or facilities within same a site or a building. The three types are themselves usage only, multi-function, and park type. The multi-function type is re-classified into two; public type and commercial type. Those functions have changed according to changes of society and times. Finally, for approaching to the exhibition-culture facilities with general transportation, the mean distance from the closest bus stop to those facilities each is 280m and 27 facilities are located within 670m from the closest bus stop. For approaching way using by car creates movement along road-building site-parking space-main entrance of building. When based on main entrance by the movement, parking space located in front side of main entrance is the largest, next is in the side, and the least is in back side. Various factors such as approaching form from road to parking space and space size between main entrance and parking space influence to approaching ways of exhibition-culture facilities in Gangneung.

Taxonomical Review of the Korean Labroidei (Teleostei: Perciformes) (한국산 놀래기과 어류의 분류학적 검토)

  • Kim, Byung-Jik
    • Korean Journal of Ichthyology
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    • v.21 no.sup1
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    • pp.74-74
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    • 2009
  • The perciform suborder Labroidei comprising six families (Cichlidae, Embiotocidae, Pomacentridae, Labridae, Odacidae, and Scaridae) are characterized by having the specialized pharyngeal jaws for food processing, i.e., united fifth ceratobranchials and upper pharyngeal jaw articulating with the basicranium via diarthroses (Stiassny and Jensen, 1987). They usually inhabit in the most tropical and subtropical seas and comprise about 235 genera and roughly 2,274 species worldwide (Nelson, 2006). Concerning the Korean labroid fishes, Mori (1952) had listed 18 genera and 26 species belong to four families in his check list of Korean fishes since Jordan and Metz (1913) firstly reported six genera and seven species in only two families (Embiotocidae and Labridae). Chyung (1977) added two species, Tilapia mossambica and Cirrhilabrus temmincki, to Mori’s list and also classified them into three suborders, i.e., Embiotocina (containing only Embiotocidae), Pomacentrina (Cichlidae and Pomacentridae), and Labrina (Labridae and Scaridae). Subsequently, Lee and Kim (1996) reviewed the Korean labroidfishes taxonomically resulting in 22 genera and 32 species in five families with some taxonomical modifications including a new Korean record. It is remarkable to be added many new Korean recordsto the pomacentrids or the labrids for recent 10 years (Koh et al., 1995; Yoo et al., 1995; Koh et al., 1997; Myoung, 1997; Choi and Kim, 2000; Choi et al., 2002; Kim and Go, 2003). Recently, Kim et al. (2005) briefly described all members of the Korean Labroidei with a color photograph or a figure, recognizing 27 genera and 42 species in five families. In the present study, the current taxonomical status of the Korean labroid fishes including distributional features is summarized based both on specimens collected from the Korean waters and on literature survey to provide bio-information of the Korean native fish species. As a result, the Korean labroid fishes totally consist of 27 genera and 44 species in five families, that is, Cichlidae (1 species), Embiotocidae (3), Pomacentridae (15), Labridae (22), and Scaridae (2). They distributed mainly in the coastal waters of the South Sea, Korea, however, most pomacentrids or labrids occur in the coastal waters of Jeju Island only, although some species were observed in their larval or juvenile stages only from coastal waters of the island. Interestingly, several species are expanding their distribution north to Ulreung and Dok islands in the East Sea, Korea lately.

Neritic Paleocurrent Analysis of Pennsylvanian Tethyan Sea at Samcheog Coalfield, Korea (후기(後期) 석탄기(石炭紀) 테티스해내(海內) 한국 삼척탄전(三涉炭田)의 천해류(淺海流) 분석(分折))

  • Kim, Haang Mook
    • Economic and Environmental Geology
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    • v.11 no.1
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    • pp.21-37
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    • 1978
  • The depositional environment of the Manhang and the Geumcheon Formation of the Pennsylvanian Gomog Croup is revealed to the shallow neritic marine milieu in this paper also as the results of Park (1963), Cheong(1975) and Kim (1976), through the analyses of stratigraphy, paleocurrent, properties of cross-beddings and sedimentational features. The formations contains some possible terrestrial sediments suggesting the paralic environment, which are however not recognized definitely within them. The paleocurrent analysis is made to the Manhang Formation only. The paleocurrent of the formation is known to belong to the shallow neritic longshore current. The paleocurrent analysis is based chiefly on the cross-bedding analysis, and subordinately on the texture of elastic coarse sediments. The paleocurrent mean is determined to $269^{\circ}$, that is, from east to west, of which direction is interpreted to the right angle to the slope of the basinal depository plane and also the parallel with die depositional strike, according to Klein (1960) and Selley's (1968) criteria. The variance value of paleocurrent directions of the Manhang Formation in the whole area studied is 6,374, and the values range from 3,394 to 6,957 according to the dirstricts. The paleocurreut pattern of the whole area shows polymodel, and the patterns in each district range from trimodel to quadrimodel. Those models approach to the shallow marine or paralic model of Tohill and Picard (1966), Picard and High (1968 a), Pisnak (1957) and Pettijohn (1962). The mean value of maximum inclinations of cross-beddings of the whole area is $19.9^{\circ}$ with the standard deviation of 8.4, and ranges from $15.6^{\circ}$ to $21.7^{\circ}$ in the districts. Comparing the histogram showing the frequency distribution of the maximum inclinations of cross-beddings of the Manhang Formation with the Pettijohn's (1962) histogram, it is found that the model approaches to his marine model. The Pennsylvanian Gomog Group of the coalfield is considered to have had been deposited in the pseudogeosynclinal zone on the plateau by the transgression of the Tethyan sea caused by the epirogenic movements during the Pennsylvanian Period.

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Implications of Deep Nitrite in the Ulleung Basin (울릉 분지 저층수의 아질산염)

  • Lee, Tong-Sup;Kim, Il-Nam;Kang, Dong-Jin;Kim, Dong-Seon
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.3
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    • pp.239-243
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    • 2007
  • Presence of bottom water nitrite in the Ulleung Basin was remarkable because it is totally unexpected phenomenon at such an oxygen-rich environment. Yet no scientific explanation was set forward. Of several plausible explanations, following the Ockham's suggestion, a leaching of nitrite as an intermediate product of denitrification in the top sediment at the slope is most agreeable to given environmental settings. There seems no complementary process to make up the loss of N in the Ulleung Basin, which seems contribute to the characteristically low N:P ratio in the deep waters. If warming proceeds that weakens the thermohaline circulation, a current biological pump may stall and the phytoplankton assemblage might replaced drastically. If so this will pause an utmost challenge to the ecosystem of the East/Japan Sea. Still there remains a contradictory sedimentary signature that requests further explanation regarding the N (or organic C)-cycle such as extraordinarily high organic carbon content despite abundant oxidants in the overlying waters.

General Oceanographic Factors In Yeongil Bay Of Korea, Late October 1973 (가을철 영일만수괴의 일반해양학적 특성)

  • Kwak, Hi-Sang
    • 한국해양학회지
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    • v.11 no.2
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    • pp.89-95
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    • 1976
  • Some factors of seawater such as water temperature, salinity, pH, dissolved oxygen and asturation of dissolved oxygen were determined in 5 meters intervals from surface to bottom at 11 stations in Yeongil Bay of Korea during late October 1973. Distribution pattern of water masses in Yeongil Bay during the period seemed to be heterogeneous as dividing into two parts of surface and bottom. Water temperature, pH, dissolved oxygen and saturation of dissolved oxygen of surface water mass showed higher values and salinity of the mass showed lower values than those factors of bottom water mass. Surface water mass might be originated from Tsushima current during summer season and bottom water mass from cold body of East Sea of Korea which seemed to extend to coastal zone during winter season. Land water discharge from Hyeongsan River into the Bay is considered as a minor factor playing slight role in the water mass composition of the area.

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Field Observations of Wave-Induced Currents at Bonggil Beach (동해 봉길해안에서 해빈류의 현지 관측)

  • LEE YOUNG KWEON;YANG HAE YANG;PARK IL HEUM;LEE JONG SUP;KIM JONG KYU
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.145-150
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    • 2004
  • Using the DGPS of high precision take in a bouy, the wave-induced currents were observed by Lagrange method at Bonggile beach of the East Sea. At June, the northward wave-induced currents were dominated by the SSW waves. And the southward flaws were appeared at September and November. When 0.2-0.4m wave heights attacked the beach, the mean speed of the wave-induced currents was 0.15-0.3m/s at June and September, when the 1.0-1.6m wave heights incidented at November, that was about 0.3-0.6m/s. On the other hand, the observed results were compared with the simulated results which were solved by the 2-D model, WICU-DIVAST. It was showed the reasonable agreements.

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