• Title/Summary/Keyword: coastal sea

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Clay mineral distribution and provenance in surface sediments of Central Yellow Sea Mud

  • Koo, HyoJin;Lee, YunJi;Kim, SoonOh;Cho, HyenGoo
    • Geosciences Journal
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    • v.22 no.6
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    • pp.989-1000
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    • 2018
  • The provenance of the Central Yellow Sea Mud (CYSM) in the Yellow Sea has been attracted a great deal of attention over the last three decades, but a consensus is not yet reached. In this study, 101 surface sediment samples collected from the CYSM were investigated to determine provenance and transport mechanisms in the area using the clay minerals and major element components. The Huanghe sediments are characterized by higher smectite, but the Changjiang sediments are more abundant illite contents. Western Korean rivers contain more kaolinite and chlorite than do Chinese rivers. The Chinese rivers have higher $Fe_2O_3$, MgO, and CaO than the Korean rivers at the same $Al_2O_3$ concentration. Therefore, the clay minerals and major element concentrations can be useful indicator for the source. Based on our results, we suggest that the surface sediments in CYSM were composed mainly of Changjiang sediments, mixed a partly with sediments from the Huanghe and the western Korean rivers. Although the northwestern part of CYSM is proximate to the Huanghe, the contents of smectite and CaO were extremely low. It could be evidence that the Huanghe materials do not enter directly into the CYSM due to the Shandong Peninsula Front. Considering the oceanic circulation in the Yellow Sea, the Changjiang sediments could be transported eastward with the Changjiang Diluted Water and then mixed in CYSM via the Yellow Sea Warm Current (YSWC). Huanghe sediments could be provided by coastal currents (Shandong Coastal Current and Yellow Sea Coastal Current) and the YSWC. In addition, sediments from western Korean rivers might be supplied into the CYSM deposit via the Korean Coastal Current, Transversal Current, and YSWC.

Maturity and Spawning of Lycodes tanakae in the Coastal Waters of the Middle East Sea (동해 중부연안 벌레문치(Lycodes tanakae)의 성숙과 산란)

  • Shon, Myong Ho;Yoon, Byoung Sun;Park, Jeong-Ho;Choi, Young Min;Lee, Jae Bong;Lee, Hae Won;Cha, Hyung Kee;Yang, Jae Hyeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.3
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    • pp.255-263
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    • 2014
  • We investigated the reproductive characteristics of Lycodes tanakae in the coastal waters of the middle East Sea to elucidate the species' population structure. We investigated Lycodes tanakae maturation and spawning based on samples collected by Danish seine and gill nets from January 2012 to December 2013. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. The spawning period was December to February, while fecundity ranged from 1,677 eggs at 57.3 cm (total length;TL) to 6,445 eggs at 75.7 cm. The relationship between TL and fecundity (F) was $F_e=6E-05TL^{3.127}$ ($R^2$ = 0.516), and F increased with increasing TL. We estimated the TL at 50% group maturity as 60.4 cm for females and 59.8 cm for males. This study is the first report of Lycodes tanakae reproductive characteristics in the coastal waters of the middle East Sea.

Sea Breeze Criterion and the Climatological Characteristics of the Short-time Sea Breeze in Gangneung Coastal Area (강릉 연안지역 해풍의 선정기준과 단 시간 해풍의 기후학적 특성)

  • Park, Jae-Hong;Jung, Woo-Sik;Leem, Heon-Ho;Lee, Hwa-Woon
    • Journal of the Korean earth science society
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    • v.23 no.5
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    • pp.436-441
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    • 2002
  • This study is concerned with the sea breeze criterion and climatological characteristics of the short-time sea breeze in the Gangneung coastal area. The sea breeze criteria in this area are listed here. First, the fact of the sea breeze blowing was considered to be a change of wind direction from land to sea and vice versa without terrain effect like easterly wind. Second, the sea breeze of which continuous time 1-hour or 2-hour was selected. Then the climatological characteristics of the short-time sea breeze were analyzed using the meterological data from a 10-year(1988${\sim}$1997) period. The climatological characteristics which were analyzed for the short-time sea breeze consist of the frequency, onset time, wind direction speed and temperature. Finally, this study will be helpful in meteorological application through the climatological characteristics of sea breeze along the east coast as well as Gangneung Airport.

NUMERICAL MODEL FOR STORM SURGES

  • Yamashita, Takao;Bekku, Isao
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1995.10a
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    • pp.1-4
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    • 1995
  • Storm surges are defined as abnormal changes of sea surface elevation whose periods range from several hours to days. The generation mechanism is separated into two. One is sea water suction due to atmospheric depression and the other is wind-driven sea water circulation. The former is a forced long-wave motion which is accompanied by a typhoon. (omitted)

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Three-Dimensional Finite Element Modeling for the Yellow Sea - Initial approach -

  • Suh, Seung-Won;M.G.G. Foreman
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1996.10a
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    • pp.14-14
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    • 1996
  • In order to understand the tidal hydrodynamics of the Yellow Sea and Parts of the East China Sea, we have developed a three-dimensional, fine resolution, nonlinear, harmonic finite element model. Major four tidal constituents, M$_2$, S$_2$, K$_1$ and O$_1$ are used as forcing along the open boundary. Due to the shallowness of the region, tidal results are strongly affected by the bottom roughness coefficients, especially for the quadratic form. (omitted)

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Current Observations in the Yellow Sea and the East China Sea Continental Shelf (황해 및 동중국해륙붕에서의 해류관측)

  • 최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.5 no.4
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    • pp.414-426
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    • 1993
  • A description is given of the recent techniques employed for the measurement of currents in the East China Sea continental shell The variability of the currents in the region is briefly discussed as it affects the measurement Data sources have been collated to develop an inventory of current observations in the shelf seas around Korea.

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Long-term Variation and Characteristics of Water Quality in the Garolim Coastal Areas of Yellow Sea, Korea (가로림연안 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Kim, Hyung-Chul;Kim, Pyoung-Joong;Park, Gyung-Soo;Ko, Joen-Young;Jeon, Sang-Baek;Lee, Seung-Min;Park, Jong-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.315-328
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    • 2009
  • Long-term trends and distribution patterns of water quality were investigated in the Garolim coastal areas of Yellow Sea, Korea from 1998 to 2007. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except pH and ammonia. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly classified into 4 clusters by PCA; year cluster 1997, 1998 and 2000-2002, 1999 and 2003-2006/2008. By this multi-variate analysis the annual trends were summarized as follows; In recent years, salinity increased, whereas dissolved inorganic nitrogen, nitrate nitrogen and COD decreased and water quality generally continued to be in good condition in Gsrolim coastal areas without inflow of freshwater from land. Garolim coastal areas are required to be conserved continuously as important coastal areas for fisheries.

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Deterministic Estimation of Typhoon-Induced Surges and Inundation on Korean Coastal Regions (국내 연안 태풍 해일의 결정론적 추정 및 침수 영역 예측)

  • Ku, Hyeyun;Maeng, Jun Ho;Cho, Kwangwoo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.1
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    • pp.1-8
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    • 2019
  • This research mainly focuses on examining the applicability of the deterministic model SLOSH (Sea, Lake and Overland Surges from Hurricanes) on Seas covering South Korea. Also, a simple bathtub approach which estimates coastal inundation area is validated as a first step of estimating effects of sea-level rise on the coastal cities of South Korea according to climate change. Firstly, the typhoon-induced surges are obtained from the model SLOSH by adopting historical typhoons MAEMI (0314) and BOLAVEN (1215). The results are compared to observational, typhoon-induced surge heights at several tidal stations. The coastal inundation area is estimated by comparing the maximum envelop of waves (MEOW) and the elevation of coastal land. It reproduces well the inundation area. It can be seen that this research gained applicability for estimating further potential coastal inundation with climate changes.