• Title/Summary/Keyword: Korea strait

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A Newly Recorded Sea Star, Genus Diplopteraster (Asteroidea: Velatida: Pterasteridae), from Korea Strait

  • Shin, Sook;Ubagan, Michael D.
    • Korean Journal of Environmental Biology
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    • v.35 no.2
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    • pp.101-104
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    • 2017
  • Asteroid specimens of the genus Diplopteraster were collected by trawling nets at a depth of 93 m on 05 November 2016 from the Korea Strait ($33^{\circ}41^{\prime}N$, $127^{\circ}26^{\prime}E$). The specimens were identified as Diplopteraster multipes(M. Sars, 1866), which belongs to the family Pterasteridae, order Velatida. This species is similar to other Diplopteraster species in its pentagonal stellate shape, but is distinguished by having each paxilla composed of a protruded spine, more than eight spiracles, and regularly reticulated muscular bands. It is not commonly found in shallow water. This is the first report of the genus Diplopteraster and D. multipes in Korea.

Southwestward Intrusion of Korea Strait Bottom Cold Water Observed in 2003 and 2004

  • Shin, Chang-Woong;Kim, Cheol-Soo;Byun, Sang-Kyung;Jeon, Dong-Chull;Hwang, Sang-Chull
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.291-299
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    • 2006
  • Hydrographic surveys were carried out four times in the western channel of the Korea Strait in March and August 2003 and in June and November 2004. The bottom cold water, which was lower than $10^{\circ}C$, appeared in the channel trough except in March 2003. It flowed southwestward along the shelf of Korean coasts in August 2003 and in November 2004. The width and the maximum speed of the intrusion current were about 20 km and approximately $25\;cm\;s^{-1}$, respectively, off Ulsan, Korea. The volume transport of the bottom cold water was estimated 0.019 Sv ($Sv{\equiv}10^6\;m^3\;s^{-1}$) in August 2003 and 0.026 Sv in November 2004.

A Geoacoustic Model at the SSDP-101 Long-core Site in the Korea Strait

  • Woo-Hun Ryang;Seong-Pil Kim
    • 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.

On the Cold Water Mass Around the Southeast Coast of Korean Peninsula

  • An, Hui Soo
    • 한국해양학회지
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    • v.9 no.2
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    • pp.10-18
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    • 1974
  • The cold water mass around the southeast coast of the Korean Peninsula is analyzed by using CSK data from 1966 through 1970. It is shown that this water mass flows down from the region offshore of Jukbyun to the area of Youngil Bay along the 100meter contour line of bottom topography. In ordinary summer conditions when the current velocity in the Korea Strait is usually above about 50cm/sec and the wind direction is southwest, the cold water ascends to the surface and makes the surface temperature gradient large, unless disturbed by a tropical cyclon. The bottom water of the Korea Strait is formed by the stratification after the Tsushima intermediate water and the Japan Sea intermediate water have been mixed. In winter the Tsushima intermediate water with high salinity sinks rapidly around the inlet of the Japan Sea and prevents the Japan Sea intemediate water from entering the Korea Strait.

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Redescriptions of Two Species Copepoda(Poecilostomatoida, Lichomolgidae) Associated with the Bivalve Dosinorbis japonicus from the Korea Strait (남해도 갯벌의 떡조개에 공생하는 요각류 2종의 재기재)

  • Kim, Il-Hoi
    • Animal Systematics, Evolution and Diversity
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    • v.18 no.1
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    • pp.23-33
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    • 2002
  • Two lichomolgoid copepods, Lichomolgus inflatus Tanaka and Philoconcha paphiae Yamaguti, both known very rarely since the original descriptions, are redescribed based on the specimens discovered as associates with the bivalve Dosinorbis japonicus from the Korea Strait. Lichomolgus inflatus is very closely related to L. chamarum Humes, but can be differentiated by the features of the rostrum and genital double-somite. Philoconcha paphiae is found to have an extremely variable leg armature. This is the first discovery of the two species of copepods outside the Japanese waters.

Late Pleistocene Lowstand Wedges on the Southeastern Continental Shelf of Korea (Korea Strait)

  • Yoo D. G.;Park S. C.;Park K. S.;Sunwoo D.;Han H. S.
    • 한국석유지질학회:학술대회논문집
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    • spring
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    • pp.15-21
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    • 1998
  • Sparker profiles and sediment cores collected from the Korea Strait show a distinct pattern of stacked prograding wedges consisting of three distinct units. These wedges are interpreted as the lowstand deposits formed during glacioeustatic sea-level lowstands. Repeated sea-level falls during late Pleistocene with high sediment discharge from the paleo-Nakdong River system resulted in the formation of thick lowstand wedges.

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The Fluctuation of Fishing Grounds of Hairtail, Trichiurus lepturus in the Cheju Strait by the Distribution of Feeding Biomass (제주해협에서의 이료생물 분포에 따른 갈치어장의 변동특성)

  • 김상현;노홍길
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.1
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    • pp.1-10
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    • 2002
  • Biomass distribution of zooplankton showed its lowest level in June in the Cheju Strait, and the highest one was noticed in November when the secondary productivity is considered high. The highest biomass of zooplankton appeared in the sea areas of Sta. 14 and 11 respectively with relation to oceanographic conditions and wet weight of biomass. The positions were the center part of the Cheju Strait, while the sea area of the South Sea of Korea and the northern coast of Cheju Island showed relatively low biomass distribution. The characteristic of the sea area where biomass was densely distributed was it was in patch shape. Meanwhile, biomass distribution was higher in the northern sea area of Cheju Island than In the coastal sea of the South Sea of Korea. It shows formation of hairtail fishing grounds is closely related to biomass distribution in the Cheju Strait. In addition, high biomass is displayed in the center part of the saddle shaped ocean, a boundary of the heterogeneous water mass as a feature of fall oceanographic condition. Good fishing grounds of a hairtail In the Cheju Strait were formed outside of the sea area that showed patch-shaped high biomass distribution.

Wind-induced Spatial and Temporal Variations in the Thermohaline Front in the Jeju Strait, Korea

  • Han, In-Seong;Suh, Young-Sang;Seong, Ki-Tack
    • Fisheries and Aquatic Sciences
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    • v.16 no.2
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    • pp.117-124
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    • 2013
  • We investigated the short-term and local changes in the thermohaline front in the Jeju Strait, Korea, which is usually formed during winter and spring. To do so, we compared Real-Time Observation System by Ferryboat (RTOSF) data with wind data and routinely collected oceanographic data. During February and April 2007, a thermohaline front formed in the Jeju Strait around the 13-$14^{\circ}C$ isotherms and 33.0-33.5 isohalines. The thermohaline was clearly weakened and began moving southward in mid-March. The variations in the surface temperature and salinity showed a continuous north-south oscillation of the thermohaline front with a period of 3-10 days. The speed of the short-term and local fluctuation of thermohaline front was about 5-30 cm/s. We confirmed these findings by examining the variation in the maximum temperature gradient and $14^{\circ}C$ isotherm during the study period. These short-term and local changes had not been previously detected using serial oceanographic and satellite data. Analysis of local wind data revealed a northerly wind fluctuation with a period of 3-10 days, which was clearly related to the short-term and local changes in the thermohaline front. The short-term and local changes of the thermohaline front in the Jeju Strait originated from local changes in the winter monsoon in this area.

A New Species of the Genus Janiralata (Crustacea, Isopoda, laniridae) from Korea (한국산 Janiralata 속 등각류의 1신종)

  • 장인권
    • The Korean Journal of Zoology
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    • v.34 no.1
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    • pp.64-68
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    • 1991
  • A new species of ianirid isopod from a subtidal bottom in the Korea Strait is described and illustrated under the name of Juniralata koreuensis. This species is characterized by the cephalon lacking a distinct rostrum and prominent antero-lateral expansions, the pleotelson lacking postero-lateral projections, and the male pleopod 1 having a nipple-shaped lobe on lateral apex.

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Mysidacea (Crustacea) from the Korea Strait and Its Adjacent Waters

  • Jo, Su-Geun;Ma, Chae-U;Seo, Hae-Rip;Hong, Seong-Yun
    • Animal cells and systems
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    • v.2 no.1
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    • pp.33-47
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    • 1998
  • Thirteen pelagic species of mysids, representing nine genera, are reported from the Korea Strait and its adjacent waters. Of these, seven species, Doxomysis quadrispinosa, Meterythrops microphthalma, Pleurerythrops secunda, Pseudanchialina pusilla, Siriella gracilis, S. okadgi, and S. thompsoni, are newly recorded from the Korean waters. A taxonomic key and illustrative figures are given.

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