• Title/Summary/Keyword: Korean Strait

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HIGH-RESOLUTION SEQUENCE STRATIGRAPHY: LATEST PLEISTOCENE-HOLOCENE EXAMPLE FROM THE KOREA STRAIT SHELF

  • Yoo Dong Geun;Park Soo Chul
    • 한국석유지질학회:학술대회논문집
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    • spring
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    • pp.25-35
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    • 1997
  • The latest Pleistocene-Holocene deposits on the Korea Strait shelf form a high-frequency sequence which consists of three systems tracts: the lowstand, transgressive and highstand systems tract. The lowstand systems tract is distributed on the shelf margin and trough region, whereas the highstand systems tract is confined only to the inner shelf. Although the transgressive systems tract between the lowstand systems tract and the highstand systems tract was identified over a wide area of the shelf, it is either very thin (a few meters thick) or absent.

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The Movement of the Cold Water in the Korea Strait

  • Lim, Du Byung
    • 한국해양학회지
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    • v.8 no.1
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    • pp.46-52
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    • 1973
  • From available data, the movement of the cold water in the Korea Strait was investigated. The cold water forms an undercurrent with a speed of 0.10knots near Ulgi in June. Sometimes it reaches a speed of 0.35knots. The cold water forms a sharp wdege in the western channel like a salt wedge in an estuary. The calculated volume transport of the cold water is 17,135 cubic meters per second in June. The external influences are also discussed.

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A Study on the Prediction of the Surface Drifter Trajectories in the Korean Strait (대한해협에서 표층 뜰개 이동 예측 연구)

  • Ha, Seung Yun;Yoon, Han-Sam;Kim, Young-Taeg
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.34 no.1
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    • pp.11-18
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    • 2022
  • In order to improve the accuracy of particle tracking prediction techniques near the Korean Strait, this study compared and analyzed a particle tracking model based on a seawater flow numerical model and a machine learning based on a particle tracking model using field observation data. The data used in the study were the surface drifter buoy movement trajectory data observed in the Korea Strait, prediction data by machine learning (linear regression, decision tree) using the tide and wind data from three observation stations (Gageo Island, Geoje Island, Gyoboncho), and prediciton data by numerical models (ROMS, MOHID). The above three data were compared through three error evaluation methods (Correlation Coefficient (CC), Root Mean Square Errors (RMSE), and Normalized Cumulative Lagrangian Separation (NCLS)). As a final result, the decision tree model had the best prediction accuracy in CC and RMSE, and the MOHID model had the best prediction results in NCLS.

Year-to-Year Fluctuations of Seasonal Variation of Surface Temperature in the Korea Strait (대한해협 표면수온의 계절변화와 연별변동)

  • KANG Yong Q.;LEE Byung Don
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.6
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    • pp.557-565
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    • 1984
  • The year-to-year fluctuations of seasonal variation of sea surface temperatures (SST) in the Korea Strait are studied based on monthly SST data for more than 50 years at Mitsushima ana Okinoshima in the strait. The frequency distribution of SST has two peaks at temperatures below and above the multi-year average, but that of SST anomalies has only one peak at the zero anomaly. More than $95\%$ of the anomalies are in the range of ${\pm}2^{\circ}C$. The harmonic constansts of seasonal SST variation vary from year to year. The standard deviations of annual means, annual amplitudes, ana semi-annual amplitudes are less than $1^{\circ}C$, and those of the annual ana semi-annual phases are about $5^{\circ}$ and less than $50^{\circ}$, respectively. The SST in the Korea Strait have a tendency to decrease their amplitudes as the annual means increase. Physical mechanisms responsible for the analyzed results are discussed in this paper.

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Review on Monitoring Volume Transport through Measurement of Submarine Cable Voltages around Korea (한반도 주변의 해저 케이블 전압측정을 통한 해수수송량 관측)

  • Kim, Yun-Bae;Kim, Young-Ho;Lyu, Sang-Jin;Kim, Kuh;Choi, Byeong-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.9 no.2
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    • pp.73-81
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    • 2004
  • Voltage induced by the Tsushima Current on an abandoned submarine telephone cable has been measured since March 1998 in order to monitor the volume transport through the Korea Strait. Voltage has a good linear relationship with the transport measured by bottom-mounted Acoustic Doppler Current Profilers (ADCPs) along a section spanning the Korea Strait. This paper reviews researches using submarine cables briefly; we introduce the method to measure voltage on submarine cables, present some results focusing on the example of the Korea Strait, and mention the future prospect to use other submarine cables around Korea.

Salinity Decrease and the Transport in the South Sea of Korea in Summer (여름철 남해의 저염화와 수송양)

  • Cho, Yang-Ki;Kim, Kuh;Rho, Hong-Kil
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.1
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    • pp.126-134
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    • 1995
  • The salinity data taken by Fishery Research Development Agency were analyzed to investigate the salinity decrease in the South Sea of Korea in summer. Decrease of depth-averaged salinity in June and August can not be accounted for the input of river discharge and rainfall. The low salinity water in the Cheju Strait is the only possible source for the decrease of salinities in the South Sea. A box model of the salt conservation shows that the transport in the Cheju Strait is 0.5-0.6${\times}$10$\^$6/ ㎥/sec (mean velocity is 10-13 cm/sec) which is 31-36% of the transport in the western channel of Korea Strait and the transport in the section between Cheju island and Tsushima island is 0.9-1.4${\times}$10$\^$6/ ㎥/sec when the transport in the western channel of the Korea Strait is 1.4-2.0${\times}$10$\^$6/ ㎥/sec.

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Epibionts associated with floating Sargassum horneri in the Korea Strait

  • Kim, Hye Mi;Jo, Jihoon;Park, Chungoo;Choi, Byoung-Ju;Lee, Hyun-Gwan;Kim, Kwang Young
    • ALGAE
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    • v.34 no.4
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    • pp.303-313
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    • 2019
  • Floating seaweed rafts are a surface-pelagic habitat that serve as substrates for benthic flora and fauna. Since 2008, Sargassum horneri clumps have periodically invaded the Korea Strait. In this study, the polymerase chain reaction-free small-organelles enriched metagenomics method was adopted to identify the species of epibiotic eukaryotes present in floating S. horneri fronds. A total of 185 species were identified, of which about 63% were previously undetected or unreported in Korean waters. The rafts harbored a diverse assemblage of eukaryotic species, including 39 Alveolata, 4 Archaeplastida, 95 Opisthokonts, 4 Rhizaria, and 43 Stramenopiles. Of these 185 taxa, 48 species were found at both Sargassum rafts collection stations and included 24 Stramenopiles, 17 Alveolata, and 7 Opisthokonts. Among these, the highest proportion (50%) of species was photo-autotrophic in basic trophic modes, while the proportion of phagotrophic, osmo- or saprotrophic, and parasitic modes were 43.8%, 4.2%, and 2.1%, respectively. This study demonstrates the contribution of floating Sargassum rafts as dispersal vectors that facilitate the spread of alien species.

Surface Current Fields in the Eastern East China Sea

  • Lie, Heung-Jae;Cho, Cheol-Ho
    • Journal of the korean society of oceanography
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    • v.32 no.1
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    • pp.1-7
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    • 1997
  • Surface current fields in the eastern East China Sea (ECS) were constructed by analyzing trajectories of 58 satellite-tracked surface drifters released during 1991-1996. Composite trajectories and 20-minute-by-20-minute box-averaged current vectors show that the basic current pattern composes of: the Kuroshio main stream, which turns eastward toward the Tokara Strait; a northward branch current of the Kuroshio on the ECS outer shelf deeper than 100 m; and an anticyclonic circulation in the northern Okinawa Trough west of Kyushu. The northward branch current sharply changes its direction to the northeast when it crosses a line connecting Cheju Island, Korea and Goto Islands, Japan. The basic pattern of current field changes slightly from winter to summer, and the main axis of the Tsushima Current in the Korea Strait is found to shift seasonally. The drifter experiment does not support the claim that the Yellow Sea Warm Current is separated from the northward branch current on the outer shelf southeast of Cheju Island. We suggest that the use of the term 'Tsushima Current' be limited to the northeast channel flow in the Korea Strait. The new term 'Kuroshio Branch Current' is suggested for the northward branch current on the outer shelf south of Cheju-do, which is separated from the Kuroshio.

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Numerical Experiment on the Ulleung Eddy due to the Variation of the Tsushima Current in the East Sea

  • KIM Soon Young;LEE Jae Chul;LEE Hyong Sun;SHIM Tae Bo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.6
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    • pp.1033-1043
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    • 1997
  • In order to understand the generation mechanism of the Ulleung Eddy, we carried out a series of numerical experiments using the nonlinear 11/2 - layer model allowing the inflow of the Tsushima Current. According to our numerical results, the Ulleung Eddy was generated due to the inflow variations of the Tsushima Current. Its inflow through the Korea Strait was deflected to the east due to the Coriolis force and the nonlinear self advection. Thus, an anticyclonic motion was formed at the north of the Korea Strait. The inflow became a coastal boundary current, and finally flowed out model ocean through the eastern exit. When the speed of inflow decreased slowly, the eddy- like motion at the north of the Korea Strait changed into an enclosed anticyclonic eddy of about 200 km in diameter. The Ulleung Eddy became circular shape due to the nonlinear self advection, then changed into elliptical shape in meridional direction because of the blocking effect of the western boundary.

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Distribution of Fish Larvae and the Front Structure of the Korea Strait in Summer (여름철 대한해협의 전선구조에 따른 자치어의 분포 특성)

  • Kim, Sung;Yoo, Jae-Myung
    • Korean Journal of Ichthyology
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    • v.11 no.1
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    • pp.72-85
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    • 1999
  • A study on the larval fish assemblage around the front area was conducted in the Korea Strait in August, 1993. The front was found in the shelf break located in $35{\sim}36^{\circ}N$. A total of 125 species were found in the study area. Of these Engraulis japonicus was the most dominant species comprising 84.3% of the total fish larvae collected and followed by Maurolicus muelleri accounting for 7.7%. Gobiidae, Callionymidae and Pomacentridae showed higher frequency of occurrence. These five species can be divided into three groups. First group was comprised in the larval fish species such as E. japonicus and Callionymidae which were found in the whole study area. The second group was comprised of Gobiidae and Pomacentridae which were found in the warm area located in the southern part of the front area. The other species was M. muelleri found in the cold area located in the northern part of the front area including the front area. The assemblage, geological distribution and body length composition of the fish larvae in the Korea Strait would be mainly determined by the spawning ecology of the fishes, and the geological distribution and structure of the front which is formed in the ocean boundary between the Tsushima Current and the East Sea Cold Water.

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